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Prostate cancer is frequently treated with radiotherapy. Unfortunately, aggressive radioresistant relapses can arise, and the molecular underpinnings of radioresistance are unknown. Modern clinical radiotherapy is evolving to deliver higher doses of radiation in fewer fractions (hypofractionation). We therefore analyzed genomic, transcriptomic, and proteomic data to characterize prostate cancer radioresistance in cells treated with both conventionally fractionated and hypofractionated radiotherapy. Independent of fractionation schedule, resistance to radiotherapy involved massive genomic instability and abrogation of DNA mismatch repair. Specific prostate cancer driver genes were modulated at the RNA and protein levels, with distinct protein subcellular responses to radiotherapy. Conventional fractionation led to a far more aggressive biomolecular response than hypofractionation. Testing preclinical candidates identified in cell lines, we revealed POLQ (DNA Polymerase Theta) as a radiosensitizer. POLQ-modulated radioresistance in model systems and was predictive of it in large patient cohorts. The molecular response to radiation is highly multimodal and sheds light on prostate cancer lethality.SignificanceRadiation is standard of care in prostate cancer. Yet, we have little understanding of its failure. We demonstrate a new paradigm that radioresistance is fractionation specific and identified POLQ as a radioresistance modulator.

Hypofractionated radiotherapy (RT) has become a trend in the modern era, as advances in RT techniques, including intensity-modulated RT and image-guided RT, enable the precise and safe delivery of high-dose radiation. Hypofractionated RT offers convenience and can reduce the financial burden on patients by decreasing the number of fractions. Furthermore, hypofractionated RT is potentially more beneficial for tumors with a low α/β ratio compared with conventional fractionation RT. Therefore, hypofractionated RT has been investigated for various primary cancers and has gained status as a standard treatment recommended in the guidelines. In genitourinary (GU) cancer, especially prostate cancer, the efficacy, and safety of various hypofractionated dose schemes have been evaluated in numerous prospective clinical studies, establishing the standard hypofractionated RT regimen. Hypofractionated RT has also been explored for gynecological (GY) cancer, yielding relevant evidence in recent years. In this review, we aimed to summarize the representative evidence and current trends in clinical studies on hypofractionated RT for GU and GY cancers addressing several key questions. In addition, the objective is to offer suggestions for the available dose regimens for hypofractionated RT by reviewing protocols from previous clinical studies. [ABSTRACT FROM AUTHOR]

Several recent studies have investigated the use of hypofractionated radiotherapy (HFRT) for various cancers. However, HFRT for non-small cell lung cancer (NSCLC) with or without concurrent chemotherapy is not yet widely used because of concerns about serious side effects and the lack of evidence for improved treatment results. Investigations of HFRT with concurrent chemotherapy in NSCLC have usually been performed in single-arm studies and with a small number of patients, so there are not yet sufficient data. Therefore, the Korean Society for Radiation Oncology Practice Guidelines Committee planned this review article to summarize the evidence on HFRT so far and provide it to radiation oncology clinicians. In summary, HFRT has demonstrated promising results, and the reviewed data support its feasibility and comparable efficacy for the treatment of locally advanced NSCLC. The incidence and severity of esophageal toxicity have been identified as major concerns, particularly when treating large fraction sizes. Strategies, such as esophagus-sparing techniques, image guidance, and dose constraints, may help mitigate this problem and improve treatment tolerability. Continued research and clinical trials are essential to refine treatment strategies, identify optimal patient selection criteria, and enhance therapeutic outcomes. [ABSTRACT FROM AUTHOR]

PURPOSE: Hypofractionation is noninferior to conventional fractionation in the treatment of localized prostate cancer. Using results from the European Society of Radiation Oncologys (ESTRO) Global Impact of Radiotherapy in Oncology (GIRO) initiative survey on hypofractionation, this study identifies rates of adoption, facilitating factors, and barriers to adoption of hypofractionation in prostate cancer across World Bank income groups. MATERIALS AND METHODS: The ESTRO-GIRO initiative administered an international, anonymous, electronic survey to radiation oncologists from 2018 to 2019. Physician demographics, clinical practice characteristics, and hypofractionation regimen use (if any) for several prostate cancer scenarios were collected. Responders were asked about specific justifications and barriers to adopting hypofractionation, and responses were stratified by World Bank income group. Multivariate logistic regression models were used to analyze variables associated with hypofractionation preference. RESULTS: A total of 1,157 physician responses were included. Most respondents (60%) were from high-income countries (HICs). In the curative setting, hypofractionation was most often preferred in low- and intermediate-risk prostate cancers, with 52% and 47% of respondents reporting hypofractionation use in ≥50% of patients, respectively. These rates drop to 35% and 20% in high-risk prostate cancer and where pelvic irradiation is indicated. Most respondents (89%) preferred hypofractionation in the palliative setting. Overall, respondents from upper-middle-income countries and lower-middle- and low-income countries were significantly less likely to prefer hypofractionation than those from HICs (P < .001). The most frequently cited justification and barrier were availability of published evidence and fear of worse late toxicity, respectively. CONCLUSION: Hypofractionation preference varies by indication and World Bank income group, with greater acceptance among providers in HICs for all indications. These results provide a basis for targeted interventions to increase provider acceptance of this treatment modality.

Background: The benefit of prophylactic whole pelvis radiation therapy (WPRT) in prostate cancer has been debated for decades, with evidence based mainly on conventional fractionation targeting pelvic nodes. Aim: This retrospective cohort study aimed to explore the impact of adding moderately hypofractionated pelvic radiotherapy to prostate-only irradiation (PORT) on prognosis, toxicity, and quality of life in real-world settings. Materials and methods: Patients with high-risk and conventionally staged prostate cancer (cT1-3N0M0) treated with moderately hypofractionated WPRT or PORT, using external beam radiotherapy alone or combined with high-dose-rate brachytherapy, at Örebro University Hospital between 2008 and 2021 were identified. Biochemical failure-free survival (BFFS), metastasis-free survival (MFS), prostate cancer-specific survival (PCSS), and overall survival (OS) were compared using Kaplan-Meier method and Cox proportional hazards. Toxicity and quality of life measures were also analysed. Results: Among 516 patients (227 PORT, 289 WPRT), 5-year BFFS rates were 77 % (PORT) and 74 % (WPRT), adjusted HR=1.50 (95 % CI=0.88–2.55). No significant differences were found in MFS, PCSS, or OS in main analyses. WPRT was associated with a higher risk of acute grade ≥ 2 and 3 genitourinary toxicities whereas no differences in late toxicities or quality of life between PORT and WPRT were observed. Conclusion: We found no significant differences in oncological outcomes or quality of life when comparing moderately hypofractionated PORT to WPRT. Some differences in toxicity patterns were observed. Despite caveats related to study design, our findings support the need for further research on WPRT’s impact on treatment-related and patient-reported outcomes.

Implementation of ultra-high dose-rate FLASH radiotherapy (FLASH-RT) is rapidly gaining traction as a unique cancer treatment modality able to dramatically minimize normal tissue toxicity while maintaining antitumor efficacy compared with standard-of-care radiotherapy at conventional dose rate (CONV-RT). The resultant improvements in the therapeutic index have sparked intense investigations in pursuit of the underlying mechanisms. As a preamble to clinical translation, we exposed non-tumor-bearing male and female mice to hypofractionated (3 × 10 Gy) whole brain FLASH- and CONV-RT to evaluate differential neurologic responses using a comprehensive panel of functional and molecular outcomes over a 6-month follow-up. In each instance, extensive and rigorous behavioral testing showed FLASH-RT to preserve cognitive indices of learning and memory that corresponded to a similar protection of synaptic plasticity as measured by long-term potentiation (LTP). These beneficial functional outcomes were not found after CONV-RT and were linked to a preservation of synaptic integrity at the molecular (synaptophysin) level and to reductions in neuroinflammation (CD68+ microglia) throughout specific brain regions known to be engaged by our selected cognitive tasks (hippocampus, medial prefrontal cortex). Ultrastructural changes in presynaptic/postsynaptic bouton (Bassoon/Homer-1 puncta) within these same regions of the brain were not found to differ in response to dose rate. With this clinically relevant dosing regimen, we provide a mechanistic blueprint from synapse to cognition detailing how FLASH-RT reduces normal tissue complications in the irradiated brain.SignificanceFunctional preservation of cognition and LTP after hypofractionated FLASH-RT are linked to a protection of synaptic integrity and a reduction in neuroinflammation over protracted after irradiation times.

INTRODUCTION: Treatment for glioblastomas, aggressive and nearly uniformly fatal brain tumors, provide limited long-term success. Immunosuppression by myeloid cells in both the tumor microenvironment and systemic circulation are believed to contribute to this treatment resistance. Standard multi-modality therapy includes conventionally fractionated radiotherapy over 6 weeks; however, hypofractionated radiotherapy over 3 weeks or less may be appropriate for older patients or populations with poor performance status. Lymphocyte concentration changes have been reported in patients with glioblastoma; however, monocytes are likely a key cell type contributing to immunosuppression in glioblastoma. Peripheral monocyte concentration changes in patients receiving commonly employed radiation fractionation schemes are unknown. METHODS: To determine the effect of conventionally fractionated and hypofractionated radiotherapy on complete blood cell leukocyte parameters, retrospective longitudinal concentrations were compared prior to, during, and following standard chemoradiation treatment. RESULTS: This study is the first to report increased monocyte concentrations and decreased lymphocyte concentrations in patients treated with conventionally fractionated radiotherapy compared to hypofractionated radiotherapy. DISCUSSION: Understanding the impact of fractionation on peripheral blood leukocytes is important to inform selection of dose fractionation schemes for patients receiving radiotherapy.

BackgroundTo evaluate acute and late genitourinary and gastrointestinal toxicities and patient reported urinary and sexual function following accelerated, hypofractionated external beam radiotherapy to the prostate, seminal vesicles and pelvic lymph nodes and high dose rate (HDR) brachytherapy or stereotactic body radiation therapy (SBRT) prostate boost.MethodsPatients at a single institution with NCCN intermediate- and high-risk localized prostate cancer with logistical barriers to completing five weeks of whole pelvic radiotherapy (WPRT) were retrospectively reviewed for toxicity following accelerated, hypofractionated WPRT (41.25 Gy in 15 fractions of 2.75 Gy). Patients also received prostate boost radiotherapy with either HDR brachytherapy (1 fraction of 15 Gy) or SBRT (19 Gy in 2 fractions of 9.5 Gy). The duration of androgen deprivation therapy was at the discretion of the treating radiation oncologist. Toxicity was evaluated by NCI CTCAE v 5.0.ResultsBetween 2015 and 2017, 22 patients with a median age of 71 years completed accelerated, hypofractionated WPRT. Median follow-up from the end of radiotherapy was 32 months (range 2-57). 5%, 73%, and 23% of patients had clinical T1, T2, and T3 disease, respectively. 86% of tumors were Gleason grade 7 and 14% were Gleason grade 9. 68% and 32% of patients had NCCN intermediate- and high-risk disease, respectively. 91% and 9% of patients received HDR brachytherapy and SBRT prostate boost following WPRT, respectively. Crude rates of grade 2 or higher GI and GU toxicities were 23% and 23%, respectively. 3 patients (14%) had late or persistent grade 2 toxicities of urinary frequency and 1 patient (5%) had late or persistent GI toxicity of diarrhea. No patient experienced grade 3 or higher toxicity at any time. No difference in patient-reported urinary or sexual function was noted at 12 months.ConclusionsAccelerated, hypofractionated whole pelvis radiotherapy was associated with acceptable GU and GI toxicities and should be further validated for those at risk for harboring occult nodal disease.

Background: As breast augmentation has become more popular, an increasing number of women with augmented breasts require treatment for breast cancer. This study aimed to assess the outcomes of postoperative whole breast radiation therapy (WB-RT) in Asian patients with breast cancer who underwent prior cosmetic breast implantation. Methods: We retrospectively reviewed the medical records of 61 patients with breast cancer who had prior cosmetic breast implants (prior-CBI) and underwent breast-conserving surgery (BCS) and WB-RT between 2015 and 2020. The median implant volume was 238.8 cc, with a median interval of 84.7 months between the prior-CBI and BCS. WB-RT was administered with either conventional fractionation (CF-RT) at 50 Gy in 25 fractions (N = 36) or hypofractionation (HF-RT) at 42.6 Gy in 16 fractions (N = 25). The incidences of implant-related complications (IRC) and their contributing factors were analyzed. Results: After a median follow-up of 43.5 months, the 3-year cumulative incidences of IRC and implant loss were 17.2% and 4.9%, respectively. Among the four (6.6%) patients who opted for implant removal after RT, three were potentially related to RT-related capsular contracture. There was no difference in the 3-year cumulative IRC rates following CF-RT and HF-RT (12.2% and 26.7%, respectively; p = 0.120). The risk factors for IRC included a larger implant size (> 260 cc) and a higher ratio of breast tissue to implant volume. Conclusions: This study demonstrated a favorable safety profile of WB-RT for treatment of breast cancer in Asian women with prior-CBI. The integration of HF-RT following BCS was thought to be a feasible approach. [ABSTRACT FROM AUTHOR]

BackgroundPatients with non-small-cell lung cancer (NSCLC) that is resistant to PD-1 and PD-L1 (PD[L]-1)-targeted therapy have poor outcomes. Studies suggest that radiotherapy could enhance antitumour immunity. Therefore, we investigated the potential benefit of PD-L1 (durvalumab) and CTLA-4 (tremelimumab) inhibition alone or combined with radiotherapy.MethodsThis open-label, multicentre, randomised, phase 2 trial was done by the National Cancer Institute Experimental Therapeutics Clinical Trials Network at 18 US sites. Patients aged 18 years or older with metastatic NSCLC, an Eastern Cooperative Oncology Group performance status of 0 or 1, and progression during previous PD(L)-1 therapy were eligible. They were randomly assigned (1:1:1) in a web-based system by the study statistician using a permuted block scheme (block sizes of three or six) without stratification to receive either durvalumab (1500 mg intravenously every 4 weeks for a maximum of 13 cycles) plus tremelimumab (75 mg intravenously every 4 weeks for a maximum of four cycles) alone or with low-dose (0·5 Gy delivered twice per day, repeated for 2 days during each of the first four cycles of therapy) or hypofractionated radiotherapy (24 Gy total delivered over three 8-Gy fractions during the first cycle only), 1 week after initial durvalumab-tremelimumab administration. Study treatment was continued until 1 year or until progression. The primary endpoint was overall response rate (best locally assessed confirmed response of a partial or complete response) and, along with safety, was analysed in patients who received at least one dose of study therapy. The trial is registered with ClinicalTrials.gov, NCT02888743, and is now complete.FindingsBetween Aug 24, 2017, and March 29, 2019, 90 patients were enrolled and randomly assigned, of whom 78 (26 per group) were treated. This trial was stopped due to futility assessed in an interim analysis. At a median follow-up of 12·4 months (IQR 7·8-15·1), there were no differences in overall response rates between the durvalumab-tremelimumab alone group (three [11·5%, 90% CI 1·2-21·8] of 26 patients) and the low-dose radiotherapy group (two [7·7%, 0·0-16·3] of 26 patients; p=0·64) or the hypofractionated radiotherapy group (three [11·5%, 1·2-21·8] of 26 patients; p=0·99). The most common grade 3-4 adverse events were dyspnoea (two [8%] in the durvalumab-tremelimumab alone group; three [12%] in the low-dose radiotherapy group; and three [12%] in the hypofractionated radiotherapy group) and hyponatraemia (one [4%] in the durvalumab-tremelimumab alone group vs two [8%] in the low-dose radiotherapy group vs three [12%] in the hypofractionated radiotherapy group). Treatment-related serious adverse events occurred in one (4%) patient in the durvalumab-tremelimumab alone group (maculopapular rash), five (19%) patients in the low-dose radiotherapy group (abdominal pain, diarrhoea, dyspnoea, hypokalemia, and respiratory failure), and four (15%) patients in the hypofractionated group (adrenal insufficiency, colitis, diarrhoea, and hyponatremia). In the low-dose radiotherapy group, there was one death from respiratory failure potentially related to study therapy.InterpretationRadiotherapy did not increase responses to combined PD-L1 plus CTLA-4 inhibition in patients with NSCLC resistant to PD(L)-1 therapy. However, PD-L1 plus CTLA-4 therapy could be a treatment option for some patients. Future studies should refine predictive biomarkers in this setting.FundingThe US National Institutes of Health and the Dana-Farber Cancer Institute.

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BACKGROUND: Centrally located lung tumors present treatment challenges given their proximity to mediastinal structures including the central airway, esophagus, major vessels, and heart. Therapeutic options can be limited for medically inoperable patients, particularly if they have received previous thoracic radiotherapy. High dose rate (HDR) brachyablation was developed to improve the therapeutic ratio for patients with central lung tumors. The purpose of this study is to report initial safety and efficacy outcomes with this treatment for central lung malignancies. METHODS: From September 2015 to August 2019, a total of 25 patients with 37 pulmonary tumors were treated with percutaneous HDR brachyablation. Treatment was delivered by a multi-disciplinary team of interventional radiologists, pulmonologists, and radiation oncologists. Twenty-three patients received a median dose of 21.5 Gy (range 15-27.5) in a single fraction, whereas two patients received median dose of 24.75 Gy (range 24-25.5) over 2-3 fractions. Tumor local control (LC) was evaluated by Response Evaluation Criteria in Solid Tumors v1.1. Treatment-related toxicities were graded by Common Terminology Criteria for Adverse Events v5.0, with adverse events less than 90 days defined as acute, and those occurring later were defined as late. LC, progression-free survival (PFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method. RESULTS: Of 37 treated tumors, 88% were metastatic. Tumor location was central and ultra-central in 24.3% and 54.1%, respectively. Average tumor volume was 11.6 cm3 (SD 12.4, range 0.57-62.8). Median follow-up was 19 months (range 3-48). Two-year LC, PFS, and OS were 96.2%, 29.7%, and 65.5%, respectively. Thirteen of 39 (33.3%) catheter implantation procedures were associated with trace minor pneumothorax requiring no intervention, 1 (2.5%) procedure with minor radiographic pulmonary hemorrhage, and 4 (10.3%) with major pneumothorax requiring chest tube insertions. All procedural complications resolved within 24 h from treatment. Acute grade 1-2 toxicity was identified in 4 patients, whereas none developed late toxicity beyond 90 days of follow-up. CONCLUSION: Percutaneous HDR brachyablation is a safe and promising treatment option for centrally located primary and metastatic lung tumors. Future comparisons with stereotactic body radiotherapy and other ablative techniques are warranted to expand multi-disciplinary management options.

PurposeProspective human data are lacking regarding safety, efficacy, and immunologic impacts of different radiation doses administered with combined PD-L1/CTLA-4 blockade.Patients and methodsWe performed a multicenter phase II study randomly assigning patients with metastatic microsatellite stable colorectal cancer to repeated low-dose fractionated radiation (LDFRT) or hypofractionated radiation (HFRT) with PD-L1/CTLA-4 inhibition. The primary endpoint was response outside the radiation field. Correlative samples were analyzed using multiplex immunofluorescence (IF), IHC, RNA/T-cell receptor (TCR) sequencing, cytometry by time-of-flight (CyTOF), and Olink.ResultsEighteen patients were evaluable for response. Median lines of prior therapy were four (range, 1-7). Sixteen patients demonstrated toxicity potentially related to treatment (84%), and 8 patients had grade 3-4 toxicity (42%). Best response was stable disease in 1 patient with out-of-field tumor shrinkage. Median overall survival was 3.8 months (90% confidence interval, 2.3-5.7 months). Correlative IF and RNA sequencing (RNA-seq) revealed increased infiltration of CD8+ and CD8+/PD-1+/Ki-67+ T cells in the radiation field after HFRT. LDFRT increased foci of micronuclei/primary nuclear rupture in two subjects. CyTOF and RNA-seq demonstrated significant declines in multiple circulating immune populations, particularly in patients receiving HFRT. TCR sequencing revealed treatment-associated changes in T-cell repertoire in the tumor and peripheral blood.ConclusionsWe demonstrate the feasibility and safety of adding LDFRT and HFRT to PD-L1/CTLA-4 blockade. Although the best response of stable disease does not support the use of concurrent PD-L1/CTLA-4 inhibition with HFRT or LDFRT in this population, biomarkers provide support that both LDFRT and HFRT impact the local immune microenvironment and systemic immunogenicity that can help guide future studies.

PurposeDosimetric and clinical predictors of radiation-induced optic nerve/chiasm neuropathy (RION) after single-fraction stereotactic radiosurgery (SRS) or hypofractionated (2-5 fractions) radiosurgery (fSRS) were analyzed from pooled data that were extracted from published reports (PubMed indexed from 1990 to June 2015). This study was undertaken as part of the American Association of Physicists in Medicine Working Group on Stereotactic Body Radiotherapy, investigating normal tissue complication probability (NTCP) after hypofractionated radiation.Methods and materialsEligible studies described dose delivered to optic nerve/chiasm and provided crude or actuarial toxicity risks, with visual endpoints (ie, loss of visual acuity, alterations in visual fields, and/or blindness/complete vision loss). Studies of patients with optic nerve sheath tumors, optic nerve gliomas, or ocular/uveal melanoma were excluded to obviate direct tumor effects on visual outcomes, as were studies not specifying causes of vision loss (ie, tumor progression vs RION).ResultsThirty-four studies (1578 patients) were analyzed. Histologies included pituitary adenoma, cavernous sinus meningioma, craniopharyngioma, and malignant skull base tumors. Prior resection (76% of patients) did not correlate with RION risk (P = .66). Prior irradiation (6% of patients) was associated with a crude 10-fold increased RION risk versus no prior radiation therapy. In patients with no prior radiation therapy receiving SRS/fSRS in 1-5 fractions, optic apparatus maximum point doses resulting in

Background: Based on the special pattern of recurrence in the excision cavity, secondary computed tomography (CT) can be introduced after hypofractionated whole breast radiotherapy with early breast cancer, aiming for accurate delineation of tumor bed boost and reduced toxicity. This study aimed to assess the volumetric changes in the lumpectomy cavity before and after hypofractionated whole breast radiation therapy (WBRT) and related clinical factors. Method: This prospective study was designed and CT simulation was done for 45 patients from September 2019 to April 2020, two radiotherapy treatment planning were generated for each patient before and after hypofractionated WBRT. The tumor bed is defined using surgical clips, seroma, and postoperative alterations. Based on the original CT and tumor bed boost CT, statistically significant decrease was examined. The relationship between various factors and the volume decrease in the excision cavity was examined. Results: The median value of reduction in the excision cavity was 15.4 cm3 with the statistical significance (P < 0.001). In multivariate linear regression, the significant variable, which predict the volume reduction, was the presence of seroma (B = 24.48, confidence interval, 13.09 to 35.87, P < 0.001). Conclusion: our results suggested significant benefit from resimulation before boost planning especially for patients with clinical evident seroma.

Abstract Background Due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, recently, Radiotherapy (RT) protocols requiring fewer sessions (hypofractionated) have been used to shorten RT treatment and minimize patient exposure to medical centers, and decrease the risk of SARS-CoV-2 infection. Methods This longitudinal, prospective, observational study aimed to compare the quality of life (QoL) and the incidence of oral mucositis and candidiasis in 66 patients with head and neck cancer (HNC) who undergo a hypofractionated RT protocol (GHipo), total of 55 Gy for 4 weeks, or a conventional RT protocol (GConv), total of 66 − 70 Gy for 6 − 7 weeks. Purpose To assess the incidence and severity of oral mucositis, the incidence of candidiasis, and QoL were evaluated using the World Health Organization scale, clinical evaluation, and the QLC-30 and H&N-35 questionnaires, respectively, at the beginning and the end of RT. Results The incidence of candidiasis did not show differences between the two groups. However, at the end of RT, mucositis had a higher incidence (p

PurposeRecent data have shown that single-fraction irradiation delivered to the whole brain in less than tenths of a second using FLASH radiotherapy (FLASH-RT), does not elicit neurocognitive deficits in mice. This observation has important clinical implications for the management of invasive and treatment-resistant brain tumors that involves relatively large irradiation volumes with high cytotoxic doses.Experimental designTherefore, we aimed at simultaneously investigating the antitumor efficacy and neuroprotective benefits of FLASH-RT 1-month after exposure, using a well-characterized murine orthotopic glioblastoma model. As fractionated regimens of radiotherapy are the standard of care for glioblastoma treatment, we incorporated dose fractionation to simultaneously validate the neuroprotective effects and optimized tumor treatments with FLASH-RT.ResultsThe capability of FLASH-RT to minimize the induction of radiation-induced brain toxicities has been attributed to the reduction of reactive oxygen species, casting some concern that this might translate to a possible loss of antitumor efficacy. Our study shows that FLASH and CONV-RT are isoefficient in delaying glioblastoma growth for all tested regimens. Furthermore, only FLASH-RT was found to significantly spare radiation-induced cognitive deficits in learning and memory in tumor-bearing animals after the delivery of large neurotoxic single dose or hypofractionated regimens.ConclusionsThe present results show that FLASH-RT delivered with hypofractionated regimens is able to spare the normal brain from radiation-induced toxicities without compromising tumor cure. This exciting capability provides an initial framework for future clinical applications of FLASH-RT.See related commentary by Huang and Mendonca, p. 662.

Background FAST-Forward aimed to identify a 5-fraction schedule of adjuvant radiotherapy delivered in 1 week that was non-inferior in terms of local cancer control and as safe as the standard 15-fraction regimen after primary surgery for early breast cancer. Published acute toxicity and 5-year results are presented here with other aspects of the trial. Design Multicentre phase III non-inferiority trial. Patients with invasive carcinoma of the breast (pT1-3pN0-1M0) after breast conservation surgery or mastectomy randomised (1 : 1 : 1) to 40 Gy in 15 fractions (3 weeks), 27 Gy or 26 Gy in 5 fractions (1 week) whole breast/chest wall (Main Trial). Primary endpoint was ipsilateral breast tumour relapse; assuming 2% 5-year incidence for 40 Gy, non-inferiority pre-defined as < 1.6% excess for 5-fraction schedules (critical hazard ratio = 1.81). Normal tissue effects were assessed independently by clinicians, patients and photographs. Sub-studies Two acute skin toxicity sub-studies were undertaken to confirm safety of the test schedules. Primary endpoint was proportion of patients with grade ≥ 3 acute breast skin toxicity at any time from the start of radiotherapy to 4 weeks after completion. Nodal Sub-Study patients had breast/chest wall plus axillary radiotherapy testing the same three schedules, reduced to the 40 and 26 Gy groups on amendment, with the primary endpoint of 5-year patient-reported arm/hand swelling. Limitations A sequential hypofractionated or simultaneous integrated boost has not been studied. Participants Ninety-seven UK centres recruited 4096 patients (1361:40 Gy, 1367:27 Gy, 1368:26 Gy) into the Main Trial from November 2011 to June 2014. The Nodal Sub-Study recruited an additional 469 patients from 50 UK centres. One hundred and ninety and 162 Main Trial patients were included in the acute toxicity sub-studies. Results Acute toxicity sub-studies evaluable patients: (1) acute grade 3 Radiation Therapy Oncology Group toxicity reported in 40 Gy/15 fractions 6/44 (13.6%); 27 Gy/5 fractions 5/51 (9.8%); 26 Gy/5 fractions 3/52 (5.8%). (2) Grade 3 common toxicity criteria for adverse effects toxicity reported for one patient. At 71-month median follow-up in the Main Trial, 79 ipsilateral breast tumour relapse events (40 Gy: 31, 27 Gy: 27, 26 Gy: 21); hazard ratios (95% confidence interval) versus 40 Gy were 27 Gy: 0.86 (0.51 to 1.44), 26 Gy: 0.67 (0.38 to 1.16). With 2.1% (1.4 to 3.1) 5-year incidence ipsilateral breast tumour relapse after 40 Gy, estimated absolute differences versus 40 Gy (non-inferiority test) were −0.3% (−1.0–0.9) for 27 Gy (p = 0.0022) and −0.7% (−1.3–0.3) for 26 Gy (p = 0.00019). Five-year prevalence of any clinician-assessed moderate/marked breast normal tissue effects was 40 Gy: 98/986 (9.9%), 27 Gy: 155/1005 (15.4%), 26 Gy: 121/1020 (11.9%). Across all clinician assessments from 1 to 5 years, odds ratios versus 40 Gy were 1.55 (1.32 to 1.83; p < 0.0001) for 27 Gy and 1.12 (0.94–1.34; p = 0.20) for 26 Gy. Patient and photographic assessments showed higher normal tissue effects risk for 27 Gy versus 40 Gy but not for 26 Gy. Nodal Sub-Study reported no arm/hand swelling in 80% and 77% in 40 Gy and 26 Gy at baseline, and 73% and 76% at 24 months. The prevalence of moderate/marked arm/hand swelling at 24 months was 10% versus 7% for 40 Gy compared with 26 Gy. Interpretation Five-year local tumour incidence and normal tissue effects prevalence show 26 Gy in 5 fractions in 1 week is a safe and effective alternative to 40 Gy in 15 fractions for patients prescribed adjuvant local radiotherapy after primary surgery for early-stage breast cancer. Future work Ten-year Main Trial follow-up is essential. Inclusion in hypofractionation meta-analysis ongoing. A future hypofractionated boost trial is strongly supported. Trial registration FAST-Forward was sponsored by The Institute of Cancer Research and was registered as ISRCTN19906132. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 09/01/47) and is published in full in Health Technology Assessment; Vol. 27, No. 25. See the NIHR Funding and Awards website for further award information. Plain language summary Patients diagnosed with early breast cancer are often recommended to have radiotherapy after surgery because research has shown that it lowers the risk of the cancer returning. However, it may cause some short- and long-term side effects. Previous clinical trials showed that the same, or even better, outcomes with a lower total dose of radiotherapy given in fewer, larger daily doses compared with older historical treatment schedules. The National Institute for Health and Care Research Health Technology Assessment Programme-funded FAST-Forward Trial aimed to see whether the number of doses could be reduced further without reducing the beneficial effects of radiotherapy. Between November 2011 and June 2014, 4096 patients agreed to take part in the FAST-Forward Main Trial testing three schedules of radiotherapy to the breast. Standard treatment given on 15 days over 3 weeks (Control Group) was compared with two different lower dose schedules where treatment was given on 5 days over 1 week (lower dose Test Groups). An additional 469 patients entered a sub-study where the gland area under the arm also received radiotherapy (Nodal Sub-Study). Main Trial 5-year results reported in April 2020 showed that the number of patients whose cancer had returned in the treated breast was low in all groups: around 2 in 100 (2.1%) for the Control Group, and 1.7% in the higher dose and 1.4% in the lower dose Test Groups. The majority of reported side effects assessed by patients and doctors up to 5 years after radiotherapy were mild for all treatment groups. Patients in the Control Group and in the lower dose Test Group experienced similar levels of side effects. More side effects were reported in the higher dose Test Group, although differences were small. Overall, the FAST-Forward findings suggest that the lower dose 1-week schedule gave similar results in terms of the cancer returning and side effects to the standard 3-week treatment and this schedule can now be used to help treat future patients. Scientific summary Background Breast cancer is the most common malignancy in women and the second leading cause of cancer death. After a diagnosis of early breast cancer, a combination of treatments is planned by a multidisciplinary team. This usually involves surgery to remove the cancer with additional radiotherapy (RT) and systemic therapies tailored to the stage and biology of the cancer, and to the individual patient’s characteristics and wishes. Meta-analyses confirm that RT after surgery for early breast cancer reduces local cancer relapse and breast cancer deaths. Randomised controlled trials involving over 8000 patients with long-term follow-up confirmed that hypofractionated RT [fewer larger fractions (Fr; daily doses)] can be at least as safe and effective as the historic standard of 50 Gray (Gy) in 25 fractions (5 weeks) if a lower total dose is used. The UK START trials contribute much of the global data for moderate hypofractionation. START-A maintained the 5-week treatment time across all randomised groups and included two doses of a 13-fraction regimen, enabling the investigators to make unconfounded estimates of the sensitivity to fraction size. START-B tested 40 Gy in 15 fractions over 3 weeks against 50 Gy in 25 fractions over 5 weeks. Five- and ten-year results for local tumour control and late-occurring normal tissue effects (NTE) assessed by patients, clinicians and from photographs were consistent with the hypothesis that breast cancer tissue and the dose-limiting normal tissues are similarly sensitive to fraction size. The START trials had a large effect on breast cancer RT practice in the UK and worldwide. A 15-fraction schedule has been the UK standard-of-care recommended by the National Institute for Health and Care Excellence since 2009, but was thought unlikely to represent the useful limits of hypofractionation for whole breast RT. The UK FAST trial compared 28.5 Gy in 5 fractions of 5.7 Gy or 30 Gy in 5 fractions of 6 Gy, both delivered once weekly over 5 weeks, to 50 Gy in 25 fractions. The first results of the FAST trial, subsequently confirmed with the 10-year results, identified a 5-fraction schedule estimated to be radiobiologically equivalent to the 25-fraction standard in terms of late NTE. This gave impetus to the investigation of 1-week 5-fraction schedules in the phase III FAST-Forward Trial. Objectives Main Trial: to identify a 5-fraction schedule of curative RT delivered in once-daily fractions (1 week) that is at least as effective and safe as the current UK standard 15-fraction (3-week) regimen after primary surgery for early breast cancer, in terms of local tumour control, adverse effects, patient-reported outcomes (PRO) and health economic (HE) consequences. Nodal Sub-Study: to show that a 5-fraction schedule of adjuvant RT to level I–III axilla and/or level IV axilla [supraclavicular fossa (SCF)] is non-inferior to a 15-fraction standard in terms of patient-reported arm swelling and function, and to contribute additional information to the endpoints of the Main Trial. Methods FAST-Forward is a UK-wide phase III randomised non-inferiority trial testing two 1-week schedules against the 3-week regimen. Patients with early breast cancer requiring adjuvant RT were randomly allocated (1 : 1 : 1) to 40 Gy in 15 fractions over 3 weeks, 27 Gy or 26 Gy in 5 fractions over 1 week to the whole breast or chest wall (Main Trial) plus the regional lymph nodes (Nodal Sub-Study). A sequential tumour bed RT boost to the conserved breast was allowed, with centres required to specify boost intention before randomisation. Primary endpoints were local relapse (Main Trial) and patient-reported arm/hand swelling (Nodal Sub-Study). Secondary endpoints were late NTE assessed by patients and clinicians, cancer and survival outcomes. The Main Trial target sample size was 4000 patients, providing 80% power (one-sided α = 0.025) to exclude an absolute increase of 1.6% in 5-year ipsilateral breast tumour relapse (IBTR) incidence for a 5-fraction schedule compared with control, assuming 2% 5-year incidence in the 40 Gy group. Eligibility for the Main Trial was patients with complete microscopic resection of early invasive breast cancer, following breast conservation surgery or mastectomy, prescribed local RT. Inclusion criteria was age ≥ 18 years, axillary staging and/or dissection, pT1-3 pN0-1 M0 disease, written informed consent, able to comply with follow-up; concurrent anti-human epidermal growth factor receptor-2 (HER-2) therapy and/or endocrine therapies were allowed. Age ≥ 65 years with pT1 G1/2 ER+ve/HER-2−ve pN0 M0 invasive disease was excluded from protocol v2.0 due to the very low risk of local cancer relapse. Exclusions included ipsilateral microinvasive disease and/or non-gradeable tumours, contralateral and/or previous ipsilateral breast cancer, concurrent cytotoxic chemotherapy (sequential neoadjuvant or adjuvant cytotoxic therapy allowed if ≥ 2 weeks between chemotherapy and RT) and RT to any regional lymph node area (excepting lower axilla included in standard tangential fields to breast/chest wall). The whole breast clinical target volume (CTV) was either determined retrospectively from field-based tangential fields or volumed prospectively. Post-mastectomy chest wall CTV encompassed post-surgical skin flaps and underlying soft tissues to the deep fascia; underlying muscle and rib cage excluded. The lymph node CTV included the axillary chain and/or the SCF (level IV axilla) either in entirety or levels specified by the clinician. The treatment plan was optimised with 3D dose compensation to achieve the dose constraints. A comprehensive quality assurance programme involved every RT centre before trial activation and continued throughout trial accrual. The RT planning packs for the Main Trial and Nodal Sub-Study are available from www.icr.ac.uk/fastforward. Patients were assessed by clinicians for IBTR and late NTE at annual follow-up visits. Late-onset NTE in ipsilateral breast or chest wall (breast distortion, shrinkage, induration and telangiectasia; and breast or chest wall oedema and discomfort) were graded by clinicians on a 4-point scale, interpreted as none, mild, moderate, or marked. Symptomatic rib fracture, symptomatic lung fibrosis, and ischaemic heart disease were recorded. In the PRO sub-study, questionnaires were administered at baseline (pre-randomisation), 3, 6, 12, 24 and 60 months. Patient assessments used a 4-point ordinal scale, as for the clinical assessments. In the photographic sub-study, photographs were taken at baseline (pre-RT), 2 and 5 years after RT and scored on a 3-point ordinal scale. In the acute toxicity sub-study, patients were assessed pre-treatment, then weekly for 6 weeks, or longer if there was higher than grade 1 toxicity still present. Two acute toxicity studies were performed; in the first study the scoring system included oedema, which is usually related to recent surgery, and also included patients with a boost. A second study was done without these confounding issues to more accurately assess the acute toxicity of the 1-week schedules compared with the 3-weekly standard. Acute reactions of the treated breast skin were graded using Radiation Therapy Oncology Group (RTOG) criteria for the first sub-study and standard common toxicity criteria for adverse effects (CTCAE) criteria for the second. The Nodal Sub-Study inclusion criteria required pT1-3 pN1-3a M0 disease and histological involvement of axillary lymph nodes with an indication for RT to level I-III axilla and/or level IV axilla. From 2018 the Nodal Sub-Study design was amended to a 2-group trial, with no further randomisation to Test Group 1 (27 Gy). All patients in the Nodal Sub-Study were asked to consent to the PRO sub-study and photographic assessments. The following additional PRO were included in the Nodal Sub-Study: shoulder stiffness, upper limb pain, sensorimotor symptoms and arm function. A HE evaluation was conducted to assess the cost-effectiveness of whole breast RT with 26 Gy/5 fractions over 1 week compared with the 3-week schedule of 40 Gy/15 fractions. We report the 5-year primary analysis of the Main Trial and a descriptive interim analysis of the Nodal Sub-Study up to 3 years’ follow-up; formal analysis of the Nodal Sub-Study will await 5 years’ follow-up. Results Between November 2011 and June 2014, 4110 patients were enrolled in the FAST-Forward Main Trial from 97 UK centres (47 RT and 50 referring centres); 14 patients subsequently withdrew consent. One hundred and ninety patients were recruited into acute toxicity study 1, 161 patients into acute toxicity study 2, 1798 patients into the PRO sub-study, 1737 patients into the photographic assessment sub-study, 3878 patients consented to donate a blood sample and 4077 patients consented to donate their primary tissue sample. Four hundred and sixty-nine patients were recruited to the Nodal Sub-Study. The demographic and clinical characteristics at baseline were well balanced between groups. In the Main Trial, after a median follow-up of 71.5 months IBTR was recorded in 79 patients (31 in the 40 Gy group, 27 in the 27 Gy group and 21 in the 26 Gy group); hazard ratios (HRs) versus 40 Gy in 15 fractions were 0.86 (95% confidence interval 0.51 to 1.44) for 27 Gy/5 fractions and 0.67 (0.38 to 1.16) for 26 Gy/5 fractions. Estimated 5-year cumulative incidence of IBTR was 2.1% for 40 Gy (expected incidence 2%), 1.7% for 27 Gy and 1.4% for 26 Gy. Estimated absolute differences in IBTR versus 40 Gy were –0.3% (–1.0 to 0.9) for 27 Gy and –0.7% (–1.3 to 0.3) for 26 Gy. As the upper confidence limits excluded an increase in IBTR of 1.6% or more so non-inferiority can be claimed for both 5-fraction schedules compared with 40 Gy/15 fractions. At least one annual clinical assessment of NTE was available in the Main Trial for 3975 (97.0%) of 4096 patients. At 5 years, any moderate or marked clinician-assessed NTE in the breast or chest wall was reported for 98 of 986 (9.9%) 40 Gy patients, 155 (15.4%) of 1005.27 Gy patients, and 121 of 1020 (11.9%) 26 Gy patients, with a significant difference between 40 Gy and 27 Gy (0.0003) but not between 40 Gy and 26 Gy (p = 0·17). Breast shrinkage was the most prevalent moderate or marked effect at 5 years, reported in 50 (5.5%) of 916.40 Gy patients, 78 (8.2%) of 948.27 Gy patients, and 65 (6.8%) of 954.26 Gy patients. Longitudinal analysis of all annual clinical assessments of NTE over follow-up showed a significantly increased risk of any moderate or marked effect in the breast or chest wall for the 27 Gy group compared with 40 Gy with no significant difference between 26 and 40 Gy. Comparing the two 5-fraction schedules, 26 Gy had significantly lower risk of any moderate or marked breast or chest wall NTE and breast shrinkage compared with 27 Gy. Estimates of 5-year cumulative incidence of any moderate or marked clinician-assessed NTE in the breast or chest wall were 26.8% for 40 Gy, 35.1% for 27 Gy and 28.5% for 26 Gy. Retrospective subgroup analyses in the Main Trial comparing IBTR in 26 Gy versus 40 Gy provide no evidence of a differential effect according to age, grade, pathological tumour size, nodal status, tumour bed boost, treatment with adjuvant chemotherapy, HER-2 status or in triple-negative patients. Confidence intervals for the HR overlap for the subgroups, although the number of events in these analyses was small, hence results should be interpreted with caution as the statistical power is low. Subgroup analysis in the Main Trial according to type of primary surgery was not possible as there was only one IBTR event post-mastectomy in a control group patient (out of 91) and none in the 173 patients treated with 5 fractions. The two acute toxicity sub-studies comprised a total of 350 patients. Incidence of grade 3+ acute skin toxicity according to RTOG criteria was 14% for 40 Gy/15 fractions, 10% for 27 Gy/5 fractions, and 6% for 26 Gy/5 fractions in sub-study 1. For sub-study 2, acute toxicity grade 3+ according to CTCAE was 0%, 2.4% and 0%, respectively. Grade 2 toxicity was more common in 40 Gy/15 fractions compared with the two 5-fraction schedules. Four hundred and sixty-nine patients from 28 RT and 22 referral centres (183 for 40 Gy/15 fractions, 104 for 27 Gy/5 fractions and 182 for 26 Gy/5 fractions) were entered into the Nodal Sub-Study. Compared with the Main Trial, as expected more patients had higher-grade disease and nearly half had a mastectomy. Axillary clearance was performed in around 50% of patients, with the remainder having some form of nodal sampling. At this interim review at 2 years patients reported moderate or marked hand/arm swelling in 10% (40 Gy), 7% (26 Gy) and 13% (27 Gy). Prevalence of clinician-assessed lymphodema at 3 years was 8% (40 Gy), 12% (26 Gy) and 11% (27 Gy). In the cost-effectiveness work the base case analysis, mean costs and quality-adjusted life-years (QALYs) for 40 Gy/15 fractions were £31,640 and 11.08 QALYs; for 26 Gy/5 fractions these were £29,638 and 11.12 QALYs. Therefore the 26 Gy/5 fractions regimen was expected to dominate with expected cost savings of £2002 (95% interval £1245 to £2804) and higher expected QALYs: 0.04 (95% interval −0.01 to 0.09). Across simulations there was a 99.9% chance that 26 Gy/5 fractions either dominated 40 Gy/15 fractions or had an incremental cost-effectiveness ratio below £15,000/QALY. Conclusion The 26 Gy/5 fractions 1-week schedule is non-inferior to 40 Gy/15 fractions over 3 weeks for IBTR. The 26 Gy dose level is comparable to 40 Gy/15 fractions in terms of NTE assessed by patients, clinicians and from photographs, and is comparable to NTE expected after 46–48 Gy in 2 Gy fractions. The 27 Gy/5 fractions regimen was non-inferior for IBTR but had statistically significantly higher levels of many late NTE compared with the 40 and 26 Gy schedules, with late NTE rates of comparable magnitude to 50 Gy/25 fractions, the historic standard schedule. Acute skin reactions reported within the trial are low, whichever regimen is used. Prevalence rates suggest that erythema after the 1-week schedule came on slightly quicker, is less intense and settles about 2 weeks earlier than after the 3-week schedule although no formal statistical analysis of this was performed. The mildness of the acute skin toxicity associated with the 5-fraction regimens was expected. Interim results from the Nodal Sub-Study at 2–3 years’ follow-up indicate no cause for concern of an excess in NTE for 26 Gy/5 fractions compared with 40 Gy/15 fractions. Low rates of IBTR and of moderate/marked late NTE can be attributed to improvements in all diagnostic and treatment modalities and to the commitment of patients to early diagnosis and randomised trials. Beyond its safety and effectiveness, the 26 Gy/5 fractions schedule is convenient and less expensive for patients and for health services. The 26 Gy/5 fractions schedule reduces the estimated healthcare fiscal cost of breast RT by over 50%. The 5-fraction regimen reduces the machine time required for breast RT patients, thus improving patient access for other groups of cancer patients within the NHS. Study registrations FAST-Forward is registered at www.isrctn.com, ISRCTN19906132. The Main Trial is published in Lancet 2020;395:1613–26. See the NIHR Journals Library website for further project information. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 09/01/47) and is published in full in Health Technology Assessment; Vol. 27, No. 25. See the NIHR Funding and Awards website for further award information.

Objective To compare the incidence of radiation-related toxicities between conventional and hypofractionated intensity-modulated radiation therapy (IMRT) for limited-stage small cell lung cancer (SCLC), and to explore the risk factors of hypofractionated radiotherapy-induced toxicities. Methods Data were retrospectively collected from consecutive limited-stage SCLC patients treated with definitive concurrent chemoradiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from March 2016 to April 2022. The enrolled patients were divided into two groups according to radiation fractionated regimens. Common Terminology Criteria for Adverse Events (CTCAE, version 5.0) was used to evaluate the grade of radiation esophagus injuries and lung injuries. Logistic regression analyses were used to identify factors associated with radiation-related toxicities in the hypofractionated radiotherapy group. Results Among 211 enrolled patients, 108 cases underwent conventional IMRT and 103 patients received hypofractionated IMRT. The cumulative incidences of acute esophagitis grade ≥2 [38.9% (42/108) vs 35.0% (36/103), P=0.895] and grade ≥ 3 [1.9% (2/108) vs 5.8% (6/103), P=0.132] were similar between conventional and hypofractionated IMRT group. Late esophagus injuries grade ≥2 occurred in one patient in either group. No differences in the cumulative incidence of acute pneumonitis grade ≥2[12.0% (13/108) vs 5.8% (6/103), P=0.172] and late lung injuries grade ≥2[5.6% (6/108) vs 10.7% (11/103), P=0.277] were observed. There was no grade ≥3 lung injuries occurred in either group. Using multiple regression analysis, mean esophageal dose ≥13 Gy (OR=3.33, 95% CI: 1.23-9.01, P=0.018) and the overlapping volume between planning target volume (PTV) and esophageal ≥8 cm3(OR=3.99, 95% CI: 1.24-12.79, P=0.020) were identified as the independent risk factors associated with acute esophagitis grade ≥2 in the hypofractionated radiotherapy group. Acute pneumonitis grade ≥2 was correlated with presence of chronic obstructive pulmonary disease (COPD, P=0.025). Late lung injuries grade ≥2 was correlated with tumor location(P=0.036). Conclusions Hypofractionated IMRT are tolerated with manageable toxicities for limited-stage SCLC patients treated with IMRT. Mean esophageal dose and the overlapping volume between PTV and esophageal are independently predictive factors of acute esophagitis grade ≥2, and COPD and tumor location are valuable factors of lung injuries for limited-stage SCLC patients receiving hyofractionated radiotherapy. Prospective studies are needed to confirm these results. [ABSTRACT FROM AUTHOR]

Purpose: This study, conducted during the COVID-19 crisis, primarily aimed to compare the acute toxicity between conventional fractionated radiation therapy (CF-RT) with hypofractionated radiation therapy (HF-RT) among patients who underwent breast-conserving surgery or mastectomy in whom breast or chest wall and regional nodal irradiation (RNI) were indicated. The secondary endpoints were both acute and subacute toxicity, cosmesis, quality of life, and lymphedema features. Methods: In this open and non-inferiority randomized trial, patients (n = 86) were randomly allocated 2:1 in the CF-RT arm (n = 33; 50 Gy/25 fractions ± sequential boost [10 Gy/5 fractions]) versus the HF-RT arm (n = 53; 40 Gy/15 fractions ± concomitant boost [8 Gy/15 fractions]). Toxic effects and cosmesis evaluation used the Common Terminology Criteria for Adverse Events, version 4.03 (CTCAE) and the Harvard/National Surgical Adjuvant Breast and Bowel Project (NSABP)/Radiation Therapy Oncology Group (RTOG) scale. For the patientreported quality of life (QoL), the European Organisation for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ-C30) and the breast cancer-specific supplementary questionnaire (QLQ-BR23) were used. Lymphedema was assessed by comparing volume differences between the affected and contralateral arms using the Casley-Smith formula. Results: Grade 2 and grade 3 dermatitis were lower with HF-RT than with CF-RT (28% vs. 52%, and 0% vs. 6%, respectively; p = 0.022). HF-RT had a lower rate of grade 2 hyperpigmentation (23% vs. 55%; p = 0.005), compared to CF-RT. No other differences in overall rates of physician-assessed grade 2 or higher and grade 3 or higher acute toxicity between HF-RT and CF-RT were registered. There was no statistical difference between groups regarding cosmesis, lymphedema rate (13% vs. 12% HF-RT vs. CF-RT; p = 1.000), and functional and symptom scales, during both the irradiation period and after 6 months of the end of treatment. The results revealed that the subset of patients up to 65 years or older did not show a statistical difference between both arm fractionation schedules (p > 0.05) regarding skin rash, fibrosis, and lymphedema. Conclusion: HF-RT was non-inferior to CF-RT, and moderate hypofractionation showed lower rates of acute toxicity, with no changes in quality-of-life outcomes. [ABSTRACT FROM AUTHOR]

Objective: Although single-fraction high-dose-rate brachytherapy (SFHDR) for localized prostate cancer has been tried in clinical trials, relevant medical evidence is currently lacking. It is necessary to systematically analyze the safety and efficacy of SFHDR. Methods: Comprehensive and systematic searches for eligible studies were performed in PubMed, Embase, and the Cochrane Library databases. The primary endpoints included safety and efficacy, represented by toxic effects and biochemical recurrence-free survival (bRFS), respectively. The proportion rates were used as the effect measure for each study and were presented with corresponding 95% confidence intervals (CI) and related 95% prediction interval (PI). Restricted maximum-likelihood estimator (REML) and the Hartung–Knapp method were used in the meta-analysis. Results: Twenty-five studies met the inclusion criteria for quantitative analysis, including 1440 patients. The median age of patients was 66.9 years old (62–73 years old) and the median follow-up was 47.5 months (12–75 months). The estimates of cumulative occurrence for severe gastrointestinal (GI) and genitourinary (GU) toxic effects were 0.1% (95% CI 0–0.2%) and 0.4% (95% CI 0–1.2%), and for grade 2 toxic effects were 1.6% (95% CI 0.1–4.7%) and 17.1% (95% CI 5.4–33.5%), respectively. The estimate of 3‑year bRFS was 87.5% (95% CI 84.4–90.3%) and 71.0% (95% CI 63.0–78.3%) for 5‑year bRFS. The pooled bRFS rates for low-risk patients were 99.0% (95% CI 85.2–100.0%) at 3 years and 80.9% (95% CI 75.4–85.9%) at 5 years, and the risk group was found to be statistically correlated with bRFS (3-year bRFS, P < 0.01; 5‑year bRFS, P = 0.04). Conclusion: SFHDR is associated with favorable tolerability and suboptimal clinical benefit in patients with localized prostate cancer. Ongoing and planned high-quality prospective studies are necessary to verify its safety and efficacy. [ABSTRACT FROM AUTHOR]

BACKGROUND: Recent advances in radiotherapy techniques have allowed ablative doses to be safely delivered to inoperable liver tumors. In this setting, proton beam radiotherapy (PBT) provides the means to escalate radiation dose to the target volume while sparing the uninvolved liver. This study evaluated the safety and efficacy of hypofractionated PBT for liver tumors, predominantly hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). METHODS: We evaluated the prospective registry of the Proton Collaborative Group for patients undergoing definitive PBT for liver tumors. Demographic, clinicopathologic, toxicity, and dosimetry information were compiled. RESULTS: To date, 63 patients have been treated at 9 institutions between 2013 and 2019. Thirty (48%) had HCC and 25 (40%) had ICC. The median dose and biological equivalent dose (BED) delivered was 58.05 GyE (range 32.5-75) and 80.5 GyE (range 53.6-100), respectively. The median mean liver BED was 13.9 GyE. Three (4.8%) patients experienced at least one grade ≥ 3 toxicity. With median follow-up of 5.1 months (range 0.1-40.8), the local control (LC) rate at 1 year was 91.2% for HCC and 90.9% for ICC. The 1-year LC was significantly higher (95.7%) for patients receiving BED greater than 75.2 GyE than for patients receiving BED of 75.2 GyE or lower (84.6%, p = 0.029). The overall survival rate at 1 year was 65.6% for HCC and 81.8% for ICC. CONCLUSIONS: Hypofractionated PBT results in excellent LC, sparing of the uninvolved liver, and low toxicity, even in the setting of dose-escalation. Higher dose correlates with improved LC, highlighting the importance of PBT especially in patients with recurrent or bulky disease.

BackgroundThis systematic review reports on outcomes and toxicities following stereotactic radiosurgery (SRS) for non-functioning pituitary adenomas (NFAs) and presents consensus opinions regarding appropriate patient management.MethodsUsing the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a systematic review was performed from articles of ≥10 patients with NFAs published prior to May 2018 from the Medline database using the key words "radiosurgery" and "pituitary" and/or "adenoma." Weighted random effects models were used to calculate pooled outcome estimates.ResultsOf the 678 abstracts reviewed, 35 full-text articles were included describing the outcomes of 2671 patients treated between 1971 and 2017 with either single fraction SRS or hypofractionated stereotactic radiotherapy (HSRT). All studies were retrospective (level IV evidence). SRS was used in 27 studies (median dose: 15 Gy, range: 5-35 Gy) and HSRT in 8 studies (median total dose: 21 Gy, range: 12-25 Gy, delivered in 3-5 fractions). The 5-year random effects local control estimate after SRS was 94% (95% CI: 93.0-96.0%) and 97.0% (95% CI: 93.0-98.0%) after HSRT. The 10-year local control random effects estimate after SRS was 83.0% (95% CI: 77.0-88.0%). Post-SRS hypopituitarism was the most common treatment-related toxicity observed, with a random effects estimate of 21.0% (95% CI: 15.0-27.0%), whereas visual dysfunction or other cranial nerve injuries were uncommon (range: 0-7%).ConclusionsSRS is an effective and safe treatment for patients with NFAs. Encouraging short-term data support HSRT for select patients, and mature outcomes are needed before definitive recommendations can be made. Clinical practice opinions were developed on behalf of the International Stereotactic Radiosurgery Society (ISRS).

Background: The objective was to report acute toxicity and quality of life in prostate cancer patients treated with definitive hypofractionated pelvic radiation therapy. Materials and methods: Patients were designated candidates for hypofractionated pelvic radiation therapy if biopsy or imaging studies evidenced unfavorable intermediate-risk, high-risk or node-positive disease. Patients were treated using a regimen of 44 Gy to the nodal areas and simultaneous integrated boost of 60 Gy to the prostate in 20 fractions with CBCT-based imaging and volumetric arc therapy (VMAT). Patient data was obtained retrospectively; acute gastrointestinal (GI) and genitourinary (GU) toxicity was classified per Common Terminology Criteria for Adverse Events (CTCAE) v5.0 and obtained from clinical records. Quality of life was surveyed via phone call using the European Organization for Research and Treatment of Cancer (EORTC) questionnaire QLQ-PR25. Results: 78 patients were treated between May and December 2021. 83.33% of patients had high-risk disease, 16.67% had intermediate-risk disease, and 34.62% patients had node-positive disease. Median follow-up was 10.6 months. No patients presented acute grade >3 GI toxicity, and one patient presented grade 3 GU toxicity. 25.64% patients presented acute G2 GI toxicity and 17.95% patients presented acute G2 GU toxicity. 60.26% of patients responded to the EORTC-PR25 questionnaire. Mean scores for symptom scales were 11.26, 4.96 and 9.57 for Urinary Symptoms, Bowel Symptoms and Hormonal Treatment-Related Symptoms; mean scores for Sexual Activity and Functioning were 19.86 and 31.08, respectively. Conclusion: Definitive hypofractionated pelvic radiation therapy has an acceptable acute toxicity and QoL profile in this series of patients, although longer follow-up is needed to properly evaluate short and long-term toxicity. Further follow-up and patient recruitment is ongoing. [ABSTRACT FROM AUTHOR]

Background: Based on the special pattern of recurrence in the excision cavity, secondary computed tomography (CT) can be introduced after hypofractionated whole breast radiotherapy with early breast cancer, aiming for accurate delineation of tumor bed boost and reduced toxicity. This study aimed to assess the volumetric changes in the lumpectomy cavity before and after hypofractionated whole breast radiation therapy (WBRT) and related clinical factors. Method: This prospective study was designed and CT simulation was done for 45 patients from September 2019 to April 2020, two radiotherapy treatment planning were generated for each patient before and after hypofractionated WBRT. The tumor bed is defined using surgical clips, seroma, and postoperative alterations. Based on the original CT and tumor bed boost CT, statistically significant decrease was examined. The relationship between various factors and the volume decrease in the excision cavity was examined. Results: The median value of reduction in the excision cavity was 15.4 cm³with the statistical significance (P < 0.001). In multivariate linear regression, the significant variable, which predict the volume reduction, was the presence of seroma (B = 24.48, confidence interval, 13.09 to 35.87, P < 0.001). Conclusion: our results suggested significant benefit from resimulation before boost planning especially for patients with clinical evident seroma. [ABSTRACT FROM AUTHOR]

Background: Due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, recently, Radiotherapy (RT) protocols requiring fewer sessions (hypofractionated) have been used to shorten RT treatment and minimize patient exposure to medical centers, and decrease the risk of SARS-CoV-2 infection. Methods: This longitudinal, prospective, observational study aimed to compare the quality of life (QoL) and the incidence of oral mucositis and candidiasis in 66 patients with head and neck cancer (HNC) who undergo a hypofractionated RT protocol (GHipo), total of 55 Gy for 4 weeks, or a conventional RT protocol (GConv), total of 66 − 70 Gy for 6 − 7 weeks. Purpose: To assess the incidence and severity of oral mucositis, the incidence of candidiasis, and QoL were evaluated using the World Health Organization scale, clinical evaluation, and the QLC-30 and H&N-35 questionnaires, respectively, at the beginning and the end of RT. Results: The incidence of candidiasis did not show differences between the two groups. However, at the end of RT, mucositis had a higher incidence (p < 0.01) and severity (p < 0.05) in GHipo. QoL was not markedly different between the two groups. Although mucositis worsened in patients treated with hypofractionated RT, QoL did not worsen for patients on this regimen. Conclusions: Our results open perspectives for the potential use of RT protocols for HNC with fewer sessions in conditions that require faster, cheaper, and more practical treatments. [ABSTRACT FROM AUTHOR]

PurposeThis study, conducted during the COVID-19 crisis, primarily aimed to compare the acute toxicity between conventional fractionated radiation therapy (CF-RT) with hypofractionated radiation therapy (HF-RT) among patients who underwent breast-conserving surgery or mastectomy in whom breast or chest wall and regional nodal irradiation (RNI) were indicated. The secondary endpoints were both acute and subacute toxicity, cosmesis, quality of life, and lymphedema features.MethodsIn this open and non-inferiority randomized trial, patients (n = 86) were randomly allocated 2:1 in the CF-RT arm (n = 33; 50 Gy/25 fractions ± sequential boost [10 Gy/5 fractions]) versus the HF-RT arm (n = 53; 40 Gy/15 fractions ± concomitant boost [8 Gy/15 fractions]). Toxic effects and cosmesis evaluation used the Common Terminology Criteria for Adverse Events, version 4.03 (CTCAE) and the Harvard/National Surgical Adjuvant Breast and Bowel Project (NSABP)/Radiation Therapy Oncology Group (RTOG) scale. For the patient-reported quality of life (QoL), the European Organisation for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ-C30) and the breast cancer-specific supplementary questionnaire (QLQ-BR23) were used. Lymphedema was assessed by comparing volume differences between the affected and contralateral arms using the Casley–Smith formula.ResultsGrade 2 and grade 3 dermatitis were lower with HF-RT than with CF-RT (28% vs. 52%, and 0% vs. 6%, respectively; p = 0.022). HF-RT had a lower rate of grade 2 hyperpigmentation (23% vs. 55%; p = 0.005), compared to CF-RT. No other differences in overall rates of physician-assessed grade 2 or higher and grade 3 or higher acute toxicity between HF-RT and CF-RT were registered. There was no statistical difference between groups regarding cosmesis, lymphedema rate (13% vs. 12% HF-RT vs. CF-RT; p = 1.000), and functional and symptom scales, during both the irradiation period and after 6 months of the end of treatment. The results revealed that the subset of patients up to 65 years or older did not show a statistical difference between both arm fractionation schedules (p > 0.05) regarding skin rash, fibrosis, and lymphedema.ConclusionHF-RT was non-inferior to CF-RT, and moderate hypofractionation showed lower rates of acute toxicity, with no changes in quality-of-life outcomes.Clinical trial registrationClinicalTrials.gov, identifier NCT 40155531.

Purpose/objectiveHypofractionated radiotherapy (HRT) regimens for prostate cancer are emerging, but tolerance doses for late adverse events are scarce. The purpose of this study is to define dose-volume predictors for late gastrointestinal and genitourinary (GI and GU) toxicities after HRT in the multi-center NRG Oncology/RTOG 0415 low-risk prostate cancer trial (N = 521).Material/methodsTreatment in the studied HRT arm was delivered as 70 Gy at 2.5 Gy/fraction with 3D-CRT/IMRT (N = 108/413). At a median follow-up of 5.9 years, the crude late ≥Grade 2 GI and GU toxicities were 19% and 29%, respectively. For modeling, the complete HRT cohort was randomly split into training and validation (70% and 30%; preserved toxicity rates). Within training, dose-response modeling was based on dose-volume cut-points (EQD2Gy; bladder/rectum: α/β = 6 Gy/3Gy), age, acute ≥Grade 2 toxicity, and treatment technique using univariate and multivariate logistic regression on bootstrapping (UVA and MVA). Candidate predictors were determined at p ≤ 0.05, and the selected MVA models were explored on validation where model generalizability was judged if the area under the receiver-operating curve in validation (AUCvalidation) was within AUCtraining ± SD with p ≤ 0.05, and with an Hosmer-Lemeshow p-value (pHL) > 0.05.ResultsThree candidate predictors were suggested for late GI toxicity: the minimum dose to the hottest 5% rectal volume (D5%[Gy]), the absolute rectal volume

ObjectivesThe objective of this study was to analyze outcomes for patients with soft tissue sarcoma of the extremities using neoadjuvant ifosfamide-based chemotherapy and hypofractionated reduced dose radiotherapy, followed by limb-sparing surgery.Materials and methodsAn Institutional Review Board (IRB)-approved retrospective review of patients treated at a single institution between 1990 and 2013 was performed. In total, 116 patients were identified who received neoadjuvant ifosfamide-based chemotherapy and 28 Gy in 8 fractions of preoperative radiation (equivalent dose in 2 Gray fractions, 31.5 Gy [α/β 10] 36.4 Gy [α/β 3]) followed by limb-sparing surgery. Local recurrence (LR), distant failure (DF), and overall survival (OS) were calculated. Univariate and multivariate analysis for LR, DF, and OS were performed using Cox analysis. Statistical significance was set at a P

Historical conventional fractionated radiation therapy (RT) for breast cancer consisted of 1.8-2.0 Gy per fraction with a total dose of 45-60 Gy over 5-7 weeks. Based on radiobiological characteristics, a low α/β is suspected of breast cancer resulting in sensitivity to higher dose per fraction (2.5-3.0 Gy). Over the past 10 years, multiple clinical trials support the application of shorter treatment regimen with hypofractionated RT (HypoRT). Recently, ultra-HypoRT with 5 fractions showed favorable outcomes. Although the safety and efficacy of HypoRT has been supported by high-quality randomized trials, there are still some worries and doubts around HypoRT from radiation oncologists. However, the radiation oncology community have now reached an important timepoint for adopting HypoRT during the COVID-19 pandemic. The aim of this review is to provide an overview of HypoRT in breast cancer based on prospective randomized trials and discuss the special consideration regarding HypoRT. [ABSTRACT FROM AUTHOR]

Our previous study showed that two different regimens of moderate hypofractionated radiotherapy (HFRT) delivered with helical tomotherapy (HT) are well tolerated in older prostate cancer patients. We provide a longterm efficacy and toxicity after > 7 years of follow-up.

Abstract Background Several studies have reported patient-related risk factors for late rectal bleeding following conventionally fractionated radiotherapy for prostate cancer. We investigated patient-related risk factors for late rectal bleeding after hypofractionated radiotherapy. Methods A total of 231 patients with local or locally advanced prostate cancer treated with hypofractionated radiotherapy (70 or 67.2 Gy in 28 fractions) were evaluated retrospectively. All patients received intensity-modulated radiotherapy with daily image guidance. The relationships between late rectal bleeding and risk factors like diabetes, hypertension, cirrhosis, and anticoagulant use were analyzed. Results During a median follow-up of 23 months, the crude rates of grade ≥ 1, grade ≥ 2, and grade ≥ 3 late rectal bleeding were 23.8%, 16.9%, and 9.5%, respectively. Cirrhosis and anticoagulant use predicted an increased risk of grade ≥ 3 rectal bleeding in multivariable analyses (hazard ratio [HR] 14.37, 95% confidence interval [CI] 3.09–66.87, P = 0.001, and HR 2.93, 95% CI 1.14–7.55, P = 0.026, respectively). The non-anticoagulant group had a significantly superior 5-year freedom from grade ≥ 3 bleeding compared to the anticoagulant group in a propensity-weighted log-rank analysis (88.0% vs. 76.7%, P = 0.041). A receiver operating characteristic curve analysis revealed that rectal bleeding was minimized in the anticoagulant group if the equivalent dose at fractionation of 2 Gy (EQD2) V77 Gy of the rectum was

PurposeThere is considerable interest in very short (ultrahypofractionated) radiation therapy regimens to treat prostate cancer based on potential radiobiological advantages, patient convenience, and resource allocation benefits. Our objective is to demonstrate that detectable changes in health-related quality of life measured by the bowel and urinary domains of the Expanded Prostate Cancer Index Composite (EPIC-50) were not substantially worse than baseline scores.Methods and materialsNRG Oncology's RTOG 0938 is a nonblinded randomized phase 2 study of National Comprehensive Cancer Network low-risk prostate cancer in which each arm is compared with a historical control. Patients were randomized to 5 fractions (7.25 Gy in 2 weeks) or 12 fractions (4.3 Gy in 2.5 weeks). The co-primary endpoints were the proportion of patients with a change in EPIC-50 bowel score at 1 year (baseline to 1 year) >5 points and in EPIC-50 urinary score >2 points tested with a 1-sample binomial test.ResultsThe study enrolled 127 patients to 5 fractions (121 analyzed) and 128 patients to 12 fractions (125 analyzed). Median follow-up for all patients at the time of analysis was 3.8 years. The 1-year frequency for >5 point change in bowel score were 29.8% (P < .001) and 28.4% (P < .001) for 5 and 12 fractions, respectively. The 1-year frequencies for >2 point change in urinary score were 45.7% (P < .001) and 42.2% (P < .001) for 5 and 12 fractions, respectively. For 5 fractions, 32.9% of patients had a drop in 1-year EPIC-50 sexual score of ≥11 points (P = .34); for 12 fractions, 30.9% of patients had a drop in 1-year EPIC-50 sexual score of ≥ 11 points (P = .20). Disease-free survival at 2 years is 99.2% (95% confidence interval: 97.5-100) in the 5-fraction arm and 97.5% (95% confidence interval: 94.6-100) in the 12-fraction arm. There was no late grade 4 or 5 treatment-related urinary or bowel toxicity.ConclusionsThis study confirms that, based on changes in bowel and urinary domains and toxicity (acute and late), the 5- and 12-fraction regimens are well tolerated. These ultrahypofractionated approaches need to be compared with current standard radiation therapy regimens.

PurposeTo investigate the safety of accelerated hypofractionated radiation therapy (AHRT) with concurrent chemotherapy (CT) for inoperable stage III non-small cell lung cancer (NSCLC).Patients and methodsThe primary objectives were to define the maximally tolerable course of accelerated radiation therapy and to describe toxicities of therapy. Total radiation therapy remained at 60 Gy. The number of once-daily fractions in each successive cohort was reduced as follows: cohort 1, 60 Gy in 27 fractions; cohort 2, 60 Gy in 24 fractions; cohort 3, 60 Gy in 22 fractions; and cohort 4, 60 Gy in 20 fractions. Concurrent treatment consisted of weekly carboplatin area under the curve (AUC) 2 and paclitaxel 45 mg/m2. Consolidation treatment consisted of carboplatin AUC 6 and paclitaxel 200 mg/m2 every weeks × 2 cycles. Maximum tolerated dose: Of 6 patients/cohort, ≤2 patients experienced grade ≥3 toxicity, and ≤1 patient experienced grade ≥4 toxicity.Results22 patients were accrued; of those, 21 patients were evaluable between July 2012 and May 2014. Grade 5 toxicity occurred in 3 patients: 1 patient in cohort 2 (hemoptysis), 2 patients in cohort 3 (hemoptysis, pneumonitis). The maximum tolerated dose (MTD) was defined by cohort 2 (60 Gy in 2.5 Gy/fraction). Time to grade 5 toxicity was 9 months, 6 months, and 9 months after the start of treatment. The median follow-up time was 23.0 months (range, 7.6-30.6 months) in living patients, the median overall survival was 19.3 months (95% confidence interval [CI] 9.3-34.0 months), and the median progression-free survival was 12.2 months (95% CI 6.1-22.5 months).ConclusionsOnly modest hypofractionation was achievable as a result of long-term toxicities. Nevertheless, the MTD of 60 Gy given at 2.5 Gy/fraction allows completion of RT in 20% fewer treatments than conventional therapy. Further investigation of AHRT may help to better define the therapeutic index.

Background: There is a growing interest in the use of hypofractionation in the setting of post-mastectomy radiation therapy (PMRT). Here, we present an interim report on the acute toxicities and the dosimetry of a 15-day hypofractionated regimen. Materials and methods: Patients aged 18-75 years who underwent mastectomy and had pathological stage IIB-IIIC or any clinical stage who had received neoadjuvant chemotherapy were treated with PMRT at a dose of 43.5 Gy in 15 fractions. Acute toxicities were scored using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Results: Between September 2020 and September 2021, 92 patients were enrolled in the study. Majority experienced grade 1 dermatitis during the course of treatment. Skin toxicities peaked two weeks after PMRT in which 57 patients (62%) had grade 2 dermatitis and 6 patients (7%) had grade 3 dermatitis. Most resolved one month after treatment, with all resolving at three months. Grade 2 fatigue occurred in 4 patients (4%). There were no grade 3 fatigue or pneumonitis of any grade. The average V95% for the chest wall, axilla, and supraclavicular fossa were 91.5%, 99.3%, and 97.5%, respectively. Average ipsilateral lung V17 was 43.6%, while the mean heart dose averaged at 3.46 Gy. Conclusion: This interim report showed that hypofractionated PMRT is associated with a low incidence of clinically significant acute toxicities. With the use of the 3-dimensional conformal radiotherapy technique and volume-based planning, adequate target volume coverage and acceptable heart doses were achieved, although with a slightly higher ipsilateral lung dose. [ABSTRACT FROM AUTHOR]

Purpose: To study the late urinary toxicity in patients with prostate cancer with prior transurethral resection of prostate (TURP) and treated with hypofractionated prostate radiation therapy., Methods and Materials: Patients diagnosed with prostate cancer, with a prior TURP, and treated with moderate or extreme hypofractionated intensity-modulated radiation therapy (moderate hypofractionated radiation therapy [MHRT], stereotactic body radiation therapy [SBRT]), were included in this study. Severity and duration of urinary symptoms observed during serial follow-up after at least 3 months from radiation therapy were graded per National Cancer Institute Common Terminology Criteria for Adverse Events v5.0 using information from a prospectively maintained institutional database. Impact of hypofractionation and other potential contributory factors on cumulative grade 2+ late urinary toxicity was analyzed with univariable and multivariable binary logistic regression., Results: A total of 203 eligible patients were included (MHRT = 114, 64-68 Gy/25#; SBRT = 89, 35-37.5 Gy/5#). Median time from TURP to radiation therapy was 10 months (IQR, 7-16 months), similar for MHRT and SBRT. Overall, mean cavity volume was 1.17 cc (IQR, 0.5-1.35 cc), whereas in MHRT and SBRT groups it was 1.03 cc (IQR, 0.4-1.15 cc) and 1.27 cc (IQR, 0.5-1.4 cc), respectively. At a median follow-up of 37 months, cumulative grade 3 and grade 2 late urinary toxicity was 8.4% (n = 17) and 23.2% (n = 47), respectively. Grade 3 symptoms were observed at median 29 months (IQR, 19-62 months) after radiation therapy completion, lasting for a median duration of 8 months (IQR, 2-14 months). Hematuria (6.4%) and urinary obstruction (3.4%) were the chief grade 3 symptoms. Multivariable analysis for age, diabetes, pelvic radiation therapy, fraction size, prostate volume, TURP to radiation therapy duration, and TURP cavity volume showed no significant association with late grade 2+ urinary toxicity., Conclusions: In this large cohort of patients with prior TURP and treated with hypofractionated prostate radiation therapy, incidence of severe late urinary adverse effects was <10%, mainly hematuria or urinary obstruction. Most of these were temporary, and no significant contributory factors were identified for late urinary morbidity after TURP and radiation therapy., (Copyright © 2024 Elsevier Inc. All rights reserved.)

There is new data in the fractionation modalities and these are the really the practice-changing trials of last years: can we use hypo fractionated whole breast radiotherapy in patients presented with ductal carcinoma in situ? Can we realize hypofractionated whole breast radiotherapy with simultaneous integrated boost? What about hypofractionated irradiation after mastectomy with reconstruction? Can we do hypofractionation to lymph nodes without risk of increased toxicity? The purpose of this work is to respond with the last evidence-based recently presented or published data., (Copyright © 2024 Société française de radiothérapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.)

Background: In patients with early-stage breast cancer following breast surgery, ultra-hypofractionated (UHF) breast/chest wall radiation therapy (RT) has been shown to be non-inferior to a moderate-hypofractionated (MHF) regimen, with a minimal risk of breast induration, in the FAST-Forward trial, and UHF is now becoming the standard regimen in Europe. Herein, we aimed to investigate Japanese patients' attitudes toward the UHF regimen., Methods: A questionnaire-based survey was conducted at 13 RT centers in nine prefectures across Japan. All patients underwent breast-conserving surgery, followed by either conventional fractionation (2 Gy/fr) or MHF (2.66 Gy/fr) whole-breast irradiation (WBI) with or without a tumor bed boost. The questionnaire consisted of 13 questions mainly addressing quality-of-life during RT. Key questions included an 11-point scale (0-10) for rating the patients' enthusiasm for the UHF regimen and prioritization of the following treatment-related effects: treatment efficacy, acute/late adverse effects, physical/emotional/financial burden, and breast cosmesis. The patient and treatment characteristics were assessed by a physician., Results: In total, 247 questionnaires were administered between November 2022 and June 2023. The age distribution was as follows: < 50:50 s:60 s: ≥ 70 = 59 (24%):76 (30%):63 (26%):49 (20%). Sixty-nine percent of patients rated their enthusiasm for the UHF regimen at ≥ 6 out of 10 points (45% rated 10/10). Treatment efficacy was the highest priority for most patients (89%), whereas breast cosmesis the lowest priority (53%)., Conclusions: Patients' enthusiasm for UHF-WBI was observed across the cohort. These results could motivate researchers and clinicians to introduce UHF regimens in clinical practice., (© 2024. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

Background: This single center prospective observational study was conducted to evaluate the acute toxicity of hypo-fractionated radiotherapy for Japanese breast cancer patients after surgery., Methods: This study recruited patients who were scheduled for moderately hypo-fractionated radiotherapy including supraclavicular lymph node area (Cohort M) or ultra-hypo-fractionated radiotherapy for the conserved breast (Cohort U) as postoperative treatment for breast cancer. Radiotherapy plans were generated using automated planning system. Irradiation of 42.5 Gy/16 fractions (Cohort M) or 26 Gy/5 fractions (Cohort U) was delivered, and boost irradiation of 10 Gy/5 fractions was added as needed. The primary endpoint was the proportion of grade ≥ 2 acute adverse events within 90 days. The toxicities were evaluated using CTCAE ver 5.0., Results: Between January 2023 and December 2023, 123 patients (81 in Cohort M and 42 in Cohort U) were enrolled. All the included patients were Japanese and completed their planned radiotherapy and were also able to be evaluated for acute adverse events. Grade 1/2/3-5 acute adverse events were observed in 67/12/0 for Cohort M and 31/4/0 for Cohort U. The proportion of grade ≥ 2 acute adverse events within 90 days was 15% (95% confidence interval 8-24%) for Cohort M and 10% (95% confidence interval 3-23%) for Cohort U., Conclusions: The proportion of acute toxicity of hypo-fractionated radiotherapy for Japanese breast cancer patients after surgery was shown to be acceptable in this study., (© 2024. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

Purpose: Regional nodal irradiation (RNI) to the axilla and supraclavicular area presents distinct toxicities, such as lymphedema and shoulder stiffness, compared with whole-breast irradiation. There is insufficient evidence on the safety of dose-escalation in hypofractionated RNI. We aimed to evaluate and compare toxicity rates in patients with breast cancer who received hypofractionated RNI with and without dose-escalation., Methods and Materials: We retrospectively analyzed 381 patients with breast cancer treated with hypofractionated RNI between March 2015 and February 2017. Patients received either the standard-dose to the regional nodal area (43.2 Gy/16 fx; 48.7 Gy 3.5 equivalent dose [EQD2], 2 Gy equivalent dose with α/β= 3.5 Gy) or dose-escalation with a median dose of 54.8 Gy 3.5 EQD2 (range, 51.7-60.9 Gy 3.5 EQD2), depending on clinical and pathologic nodal stage. Toxicity rates of lymphedema and shoulder stiffness were assessed, and statistical analyses were conducted to identify associated factors., Results: The median follow-up time was 32.3 months (5.7-47.0 months). After radiation therapy, 71 (18.6%) patients developed lymphedema, and 48 (12.6%) developed shoulder stiffness. Patients who received dose-escalation exhibited significantly higher rates of lymphedema (32.1% vs 14.8%; odds ratio, 2.72, P = .0004) and shoulder stiffness (23.8% vs 9.4%; odds ratio, 2.01, P = .0205) compared with the standard-dose group. Moreover, dose-escalation showed a tendency to increase the severity of lymphedema and shoulder stiffness., Conclusions: Patients who received dose-escalation in hypofractionated RNI face a higher risk of developing lymphedema and shoulder stiffness compared with those who received standard-dose hypofractionated RNI. Therefore, it is crucial to implement close and frequent monitoring for early detection, along with timely rehabilitation interventions for these patients., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The other side of radiotherapy (RT), in addition to the cytotoxic effect, is the ability to modulate the immune system in terms of activation or suppression, also depending on the dose and fractionation delivered. This immune RT effect can be detected both locally in the irradiated tumor site and in the peripheral blood. The aim of this study was to assess the consequence of pelvic irradiation on peripheral immune cells and cytokine secretions in localized prostate cancer (PC) patients undergoing pelvic irradiation with a simultaneous moderately hypofractionated prostate/prostate bed boost by Volumetric Modulated Arc Therapy (VMAT). Furthermore, we analyzed whether there was a correlation between these peripheral immune parameters and acute and late genitourinary (GU) and gastrointestinal (GI) toxicity., Methods: Thirty-eight PC patients were treated with pelvis irradiation (dose per fraction 1.8 Gy) and simultaneous hypofractionated (median dose per fraction: 2.7 Gy) prostate/prostate bed boost. A longitudinal analysis was performed for 12 months on peripheral blood to assess changes in 9 different lymphocyte subpopulations by flow cytometry and 10 circulating cytokines by Multiplex Luminex assay and ELISA., Results: Our analysis revealed that basal IFN-γ serum values were significantly lower in the definitive (curative intent for patients with prostate) patient group respect to the post-operative one. All the lymphocyte subsets and IFN-α, IFN-β and Il-2 peripheral concentrations displayed significant variations between the different time points considered. The immune cell population that suffers the greatest RT toxicity in the blood was B lymphocyte. We found an interesting correlation between basal TGF-β1 and late GU toxicity. In particular, TGF-β1 concentrations before RT were significantly higher in patients that experienced grade 2-3 of late GU toxicity, respect to grade 0-1. Exploring possible correlations between some clinical/biological findings and radiation planning parameters, we found no statistical significance., Conclusions: Our study analyzed, in the context of hypofractionated radiotherapy in prostate cancer, different parameters of the peripheral immune system. We have highlighted longitudinally the peripheral behavior of the different lymphocyte subpopulations and of a group of 10 cytokines during the first year after RT. One of the analyzed cytokines, such as TGF-β1, has proven to be promising predictive factor of severe late GU toxicity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 D’Auria, Valvano, Calice, D’Esposito, Cabaro, Formisano, Bianchino, Traficante, Bianculli, Lazzari, Statuto and Rago.)

Purpose/objective(s): Merkel cell carcinoma (MCC) radiation treatment has historically consisted of standard 1.8-2 Gy fractions treated daily over 4-6 weeks. Hypofractionated treatment regimens have demonstrated tumor control and toxicity equivalence to standard fractionation regimens for common cutaneous malignancies such as basal cell and squamous cell carcinomas. Herein we report the outcomes of hypofractionated versus standard fractionation radiotherapy for MCC at our institution., Materials/methods: The study involved a retrospective review of MCC patients treated with radiotherapy. Treatment characteristics and patient outcomes, including acute toxicities, disease recurrence and survival data were collected. The cumulative incidence of local and distant failures was estimated, with death as a competing risk., Results: A total of 29 treatment courses for 24 patients were included, of which 13 involved standard fractionation with curative intent, 10 involved hypofractionated radiotherapy with curative intent, and 6 involved single fraction (8 Gy) palliative radiation. Half the patients were treated to a head/neck site. A subset of patients treated adjuvantly with curative intent included 8 standard fractionation and 8 hypofractionated radiotherapy patients. No statistically significant differences in local and/or distant failure or overall survival was observed between the patient groups., Conclusion: Hypofractionated radiotherapy for MCC was associated with similar treatment outcomes relative to standard fractionation. In our limited patient sample, hypofractionated radiation treatment achieved similar results with similar toxicity and fewer treatments. Further analysis of a larger patient population with longer follow up is needed to confirm treatment tolerability and efficacy., (© 2024. The Author(s).)

Background: The identification of the subgroups with differential treatment effects (DTE) is important for decisionmaking in personalized treatment. The DTE analysis assists in identifying patients who are more likely to benefit from a particular treatment regimen. The aim of the study was to analyze DTE in terms of the survival of glioblastoma (GBM) patients in the groups of standard radiotherapy (SRT) and hypofractionated radiotherapy (HRT) by the multicluster modeling of homogenous groups while retaining the statistical characteristics of the overall primary study cohort., Patients and Methods: The cohort of 159 patients with newly diagnosed GBM stratified according to the radiotherapy regimen (HRT group (n = 110/69.2%); SRT group (n = 49/30.8%)) was evaluated retrospectively. Forty-eight subgroups (multiclusters) were created by enumerating all possible combinations of 5 significant covariates (age, sex, the radicality of the surgical resection, chemotherapy, and Karnofsky performance status) of the Cox model. The DTE for the cancerspecific survival (CSS) within 48 modeled multiclusters were studied by comparing the interpolated Weibull CSS curves according to the Kolmogorov - Smirnov test., Results: The findings showed that the SRT group was superior to the HRT group by CSS only in 3 of the modeled clusters presenting clinical scenarios with a non-radical tumor resection, no chemotherapy, and low Karnofsky functional status (≤ 70 scores) (Cluster 10: male aged < 60; Cluster 21: female aged ≥ 60; Cluster 22: male aged ≥ 60). Most of the studied clinical variants (45 of 48 multiclusters) did not demonstrate a significant difference when comparing the interpolated Weibull curves of the CSS for the SRT and HRT groups according to the Kolmogorov - Smirnov test (p ≥ 0.05)., Conclusions: We propose a novel multicluster modeling approach that addresses DTE in relatively small samples of GBM patients receiving SRT or HRT. This original analytical method can be taken into consideration while designing new well-powered prospective trials aimed at the subgroup analysis in GBM patients who will be most beneficial from personalized treatment strategies.

Introduction: Radical prostatectomy is appropriate for any patient whose cancer appears clinically localised to prostate. However because of potential perioperative morbidity, radical prostatectomy is generally reserved for patients whose life expectancy is more than ten years. Moderate hypofractionation for localized prostate cancer is safe and effective. There is a growing body of evidence in support of extreme hypofractionation for localized prostate cancer. Hypofractionation for prostate cancer was originally carried out in the pursuit of efficiency and convenience, but has now attracted greatly renewed interest based upon a hypothesis that prostate cancers have a higher sensitivity to fraction size, reflected in a low α/β ratio, then do late responding organs at risk such as the rectum or bladder., Material and Methods: From January 2017 to December 2020 we treated 112 patients of localised Prostate Cancer with Image Guided Radiotherapy (IGRT). They were in range of 75-85 years. They were of stage T1-T3, N0 or N1. There were significant comborbidities. ECOG performance status was 0-1. They were given 3 months of Androgen Deprivation Therapy (ADT) before starting IGRT. Patients were immobilised with casts and subject to CT simulation. CBCT was taken daily. Dose was 70 Gy @ 250 cGy per fraction at a frequency of 5 fractions per week. Complete blood counts were done weekly for assessment of haematological toxicity. Androgen Deprivation Therapy was continued post IGRT., Results: All the patients were able to complete the treatment. Evaluation was done at one month, three month and six months post treatment. 104 out of 112 patients achieved complete response. Other 8 had near complete response. There were no acute grade 3-4 toxicities. Grade 1-2 toxicities like skin desquamation, diarrhoea, burning micturition were managed conservatively. Late toxicity was rectal bleeding seen after one year of completion of treatment and was managed with steroid enemas. 23 patients required argon plasma laser therapy., Conclusion: Image guided radiotherapy is well tolerated, easy to implement and an effective alternative to radical prostatectomy in elderly patients with comorbidities and low life expectancy., (Copyright © 2024 Copyright: © 2024 Annals of African Medicine.)

Radiation oncology caregivers worldwide are dedicated to advancing cancer treatment with the ultimate goal of eradicating the disease. Recognizing the inherent complexity of cancer treatment using hypo-fractionation radiotherapy (HFRT), these caregivers are committed to exploring avenues for progress and providing personalized care to each patient. Strong teams and effective workflows are an essential component to implementing safe HFRT. Every patient presents unique challenges, and as a united team of clinical and administrative professionals, radiation oncology care teams strive to drive advancements and streamline complexities in their field, guided by continuous technological innovation., (Published by Elsevier Inc.)

Data demonstrates that hypofractionation is increasingly utilized based on evidence-based guidelines. The outdated Medicare fee-for-service approach penalizes radiation oncology (RO) practices from adopting hypofractionation, even as many patients benefit. To address the flawed fee-for-service payment system, which rewards volume over value, ASTRO introduced the Radiation Oncology Case Rate (ROCR) Value-Based Payment Program. ROCR shifts payment for RO services from fee-for-service to payment per patient or per episode. To address disparities, ROCR provides an evidence-based approach through the Health Equity Achievement in Radiation Therapy (HEART) initiative, providing transportation assistance payment for the underserved. Additionally, ROCR allows practices sufficient capital to maintain existing equipment and invest in new technology. This increases patient access to technological advancements allowing for more efficient, targeted, and personalized care with improved patient outcomes at a lower overall cost., Competing Interests: Conflict of interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: The standard treatment schedule for unresectable stage III non-small cell lung cancer (NSCLC) is chemotherapy with concurrent radiation therapy (60 Gy delivered in 30 fractions), although moderately hypofractionated radiation therapy (Hypo-RT) has also been considered as an alternative strategy. This study aimed to compare the efficacy and toxicity of moderately Hypo-RT with helical TomoTherapy versus conventionally fractionated radiation therapy (Con-RT) in patients with unresectable stage III NSCLC receiving concurrent chemotherapy., Methods and Materials: In this randomized, multicenter, nonblinded phase 3 clinical trial, eligible patients were randomised at a 1:1 ratio to either the Hypo-RT group (60 Gy in 20 fractions) or Con-RT group (60 Gy in 30 fractions). All patients received 2 cycles of concurrent platinum-based chemotherapy plus 2 cycles of consolidation therapy. The primary endpoint was 3-year overall survival (OS) in the intention-to-treat population. The secondary endpoints were progression-free survival and treatment-related adverse events., Results: A total of 146 patients were enrolled from July 27, 2018, to November 1, 2021. The median follow-up was 46 months. The 3-year OS rates in the Hypo-RT and Con-RT groups were 58.4% and 38.4%, respectively (P = .02). The median OS from randomisation was 41 months in the Hypo-RT group and 30 months in the Con-RT group (hazard ratio, 0.61; 95% confidence interval, 0.40-0.94; P = .02). There was no significant difference in the rates of grade ≥2 treatment-related adverse events between the 2 groups., Conclusions: Moderately Hypo-RT using helical TomoTherapy may improve OS in patients with unresectable stage III NSCLC, while maintaining toxicity rates., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Importance: Postmastectomy radiation therapy (PMRT) improves local-regional disease control and patient survival. Hypofractionation (HF) regimens have comparable efficacy and complication rates with improved quality of life compared with conventional fractionation (CF) schedules. However, the use of HF after mastectomy in patients undergoing breast reconstruction has not been prospectively examined., Objective: To compare HF and CF PMRT outcomes after implant-based reconstruction., Design, Setting, and Participants: This randomized clinical trial assessed patients 18 years or older undergoing mastectomy and immediate expander or implant reconstruction for breast cancer (Tis, TX, or T1-3) and unilateral PMRT from March 8, 2018, to November 3, 2021 (median [range] follow-up, 40.4 [15.4-63.0] months), at 16 US cancer centers or hospitals. Analyses were conducted between September and December 2023., Interventions: Patients were randomized 1:1 to HF or CF PMRT. Chest wall doses were 4256 cGy for 16 fractions for HF and 5000 cGy for 25 fractions for CF. Chest wall toxic effects were defined as a grade 3 or higher adverse event., Main Outcomes and Measures: The primary outcome was the change in physical well-being (PWB) domain of the Functional Assessment of Cancer Therapy-Breast (FACT-B) quality-of-life assessment tool at 6 months after starting PMRT, controlling for age. Secondary outcomes included toxic effects and cancer recurrence., Results: Of 400 women (201 in the CF arm and 199 in the HF arm; median [range] age, 47 [23-79] years), 330 patients had PWB scores at baseline and at 6 months. There was no difference in the change in PWB between the study arms (estimate, 0.13; 95% CI, -0.86 to 1.11; P = .80), but there was a significant interaction between age group and study arm (P = .03 for interaction). Patients younger than 45 years had higher 6-month absolute PWB scores if treated with HF rather than CF regimens (23.6 [95% CI, 22.7-24.6] vs 22.0 [95% CI, 20.7-23.3]; P = .047) and reported being less bothered by adverse effects (mean [SD], 3.0 [0.9] in the HF arm and 2.6 [1.2] in the CF arm; P = .02) or nausea (mean [SD], 3.8 [0.4] in the HF arm and 3.6 [0.8] in the CF arm; P = .04). In the as-treated cohort, there were 23 distant (11 in the HF arm and 12 in the CF arm) and 2 local-regional (1 in the HF arm and 1 in the CF arm) recurrences. Chest wall toxic effects occurred in 39 patients (20 in the HF arm and 19 in the CF arm) at a median (IQR) of 7.2 (1.8-12.9) months. Fractionation was not associated with chest wall toxic effects on multivariate analysis (HF arm: hazard ratio, 1.02; 95% CI, 0.52-2.00; P = .95). Fewer patients undergoing HF vs CF regimens had a treatment break (5 [2.7%] vs 15 [7.7%]; P = .03) or required unpaid time off from work (17 [8.5%] vs 34 [16.9%]; P = .02)., Conclusions and Relevance: In this randomized clinical trial, the HF regimen did not significantly improve change in PWB compared with the CF regimen. These data add to the increasing experience with HF PMRT in patients with implant-based reconstruction., Trial Registration: ClinicalTrials.gov Identifier: NCT03422003.