Search

The aim of this work was to investigate whether reirradiation of recurrent glioblastoma with hypofractionated stereotactic radiation therapy (HSRT) consisting of 35 Gy in 5 fractions (35 Gy/5 fx) compared with 25 Gy in 5 fractions (25 Gy/5 fx) improves outcomes while maintaining acceptable toxicity. We conducted a prospective randomized phase 2 trial involving patients with recurrent glioblastoma (per the 2007 and 2016 World Health Organization classification). A minimum interval from first radiation therapy of 5 months and gross tumor volume of 150 cc were required. Patients were randomized 1:1 to receive HSRT alone in 25 Gy/5 fx or 35 Gy/5 fx. The primary endpoint was progression-free survival (PFS). We used a randomized phase 2 screening design with a 2-sided α of 0.15 for the primary endpoint. From 2011 to 2019, 40 patients were randomized and received HSRT, with 20 patients in each group. The median age was 50 years (range, 27-71); a new resection before HSRT was performed in 75% of patients. The median PFS was 4.9 months in the 25 Gy/5 fx group and 5.2 months in the 35 Gy/5 fx group (P =.23). Six-month PFS was similar at 40% (85% CI, 24%-55%) for both groups. The median overall survival (OS) was 9.2 months in the 25 Gy/5 fx group and 10 months in the 35 Gy/5 fx group (P =.201). Grade ≥3 necrosis was numerically higher in the 35 Gy/5 fx group (3 [16%] vs 1 [5%]), but the difference was not statistically significant (P =.267). In an exploratory analysis, median OS of patients who developed treatment-related necrosis was 14.1 months, and that of patients who did not was 8.7 months (P =.003). HSRT alone with 35 Gy/5 fx was not superior to 25 Gy/5 fx in terms of PFS or OS. Due to a potential increase in the rate of clinically meaningful treatment-related necrosis, we suggest 25 Gy/5 fx as the standard dose in HSRT alone. During follow-up, attention should be given to differentiating tumor progression from potentially manageable complications. [ABSTRACT FROM AUTHOR]

In this paper, we present a review of several selected talks presented at the CTTACC conference (Cellular Therapies in Trauma and Critical Care) held in Scottsdale, AZ in May 2023. This conference review highlights the potential for cellular therapies to "reset" the dysregulated immune response and restore physiologic functions to normal. Improvements in medical care systems and technology have increasingly saved lives after major traumatic events. However, many of these patients have complicated post-traumatic sequelae, ranging from short-term multi-organ failure to chronic critical illness. Patients with chronic critical illness have been found to have dysregulated immune responses. These abnormal and harmful immune responses persist for years after the initial insult and can potentially be mitigated by treatment with cellular therapies. The sessions emphasized the need for more research and clinical trials with cellular therapies for the treatment of a multitude of chronic illnesses: post-trauma, radiation injury, COVID-19, burns, traumatic brain injury (TBI) and other chronic infections. [ABSTRACT FROM AUTHOR]

Proton relative biological effectiveness (RBE) is a dynamic variable influenced by factors like linear energy transfer (LET), dose, tissue type, and biological endpoint. The standard fixed proton RBE of 1.1, currently used in clinical planning, may not accurately represent the true biological effects of proton therapy (PT) in all cases. This uncertainty can contribute to radiation-induced normal tissue toxicity in patients. In late-responding tissues such as the spinal cord, toxicity can cause devastating complications. This study investigated spinal cord tolerance in mice subjected to proton irradiation and characterized the influence of fractionation on proton- induced myelopathy at entrance (ENT) and Bragg peak (BP) positions. Cervical spinal cords of 8-week-old C57BL/6J female mice were irradiated with single- or multi-fractions (18x) using lateral opposed radiation fields at 1 of 2 positions along the Bragg curve: ENT (dose-mean LET = 1.2 keV/μm) and BP (LET = 6.9 keV/μm). Mice were monitored over 1 year for changes in weight, mobility, and general health, with radiation-induced myelopathy as the primary biological endpoint. Calculations of the RBE of the ENT and BP curve (RBE ENT/BP) were performed. Single-fraction RBE ENT/BP for 50% effect probability (tolerance dose (TD 50), grade II paresis, determined using log-logistic model fitting) was 1.10 ± 0.06 (95% CI) and for multifraction treatments it was 1.19 ± 0.05 (95% CI). Higher incidence and faster onset of paralysis were seen in mice treated at the BP compared with ENT. The findings challenge the universally fixed RBE value in PT, indicating up to a 25% mouse spinal cord RBE ENT/BP variation for multifraction treatments. These results highlight the importance of considering fractionation in determining RBE for PT. Robust characterization of proton-induced toxicity, aided by in vivo models, is paramount for refining clinical decision-making and mitigating potential patient side effects. [ABSTRACT FROM AUTHOR]

The optimal dose and range of radiation therapy for central nervous system nongerminomatous germ cell tumors (NGGCTs) have not been uniformly established. Therefore, this study aimed to investigate the effect of individualized radiation therapy, based on the response to induction chemotherapy combined with surgery, on the prognosis of patients with NGGCTs. Based on the imaging examination and tumor markers after induction chemotherapy and pathologic results of second-look surgery, patients with NGGCT received different radiation therapy strategies, including 30.6 Gy whole ventricular irradiation + tumor-bed boost to 54 Gy, 30.6 Gy craniospinal irradiation + tumor-bed boost to 54 Gy, 36 Gy craniospinal irradiation + tumor-bed boost to 54 Gy, and 36 Gy craniospinal irradiation + 54 Gy tumor-bed boost with 45 Gy to metastatic spinal lesions. A total of 51 patients were enrolled between January 2015 and March 2021, with a median age of 10.3 years. The 3-year event-free survival and overall survival (OS) of the entire cohort were 70.2% ± 6.9% and 77.5% ± 6.0%, respectively. The 3-year OS of patients achieving partial response after induction chemotherapy was higher than that of patients with stable disease (P =.03) or progressive disease (P =.002). The 3-year event-free survival and OS of the 18 patients receiving 30.6 Gy whole ventricular irradiation and 54 Gy tumor-bed boost were 88.9% ± 7.4% and 94.4% ± 5.4%, respectively. The results suggest that an individualized radiation therapy strategy based on response to induction chemotherapy and surgery is a feasible and promising means of achieving reduction in dose and extent of radiation in patients while still providing good response. [ABSTRACT FROM AUTHOR]

The utility of Adaptive Radiotherapy (ART) in Head and Neck Squamous Cell Carcinoma (HNSCC) remains to be ascertained. While multiple retrospective and single-arm prospective studies have demonstrated its efficacy in decreasing parotid doses and reducing xerostomia, adequate randomized evidence is lacking. ReSTART (Reducing Salivary Toxicity with Adaptive Radiotherapy) is an ongoing phase III randomized trial of patients with previously untreated, locally advanced HNSCC of the oropharynx, larynx, and hypopharynx. Patients are randomized in a 1:1 ratio to the standard Intensity Modulated Radiotherapy (IMRT) arm {Planning Target Volume (PTV) margin 5 mm} vs. Adaptive Radiotherapy arm (standard IMRT with a PTV margin 3 mm, two planned adaptive planning at 10th and 20th fractions). The stratification factors include the primary site and nodal stage. The RT dose prescribed is 66Gy in 30 fractions for high-risk PTV and 54Gy in 30 fractions for low-risk PTV over six weeks, along with concurrent chemotherapy. The primary endpoint is to compare salivary toxicity between arms using salivary scintigraphy 12 months' post-radiation. To detect a 25% improvement in the primary endpoint at 12 months in the ART arm with a two-sided 5% alpha value and a power of 80% (and 10% attrition ratio), a sample size of 130 patients is required (65 patients in each arm). The secondary endpoints include acute and late toxicities, locoregional control, disease-free survival, overall survival, quality of life, and xerostomia scores between the two arms. The ReSTART trial aims to answer an important question in Radiation Therapy for HNSCC, particularly in a resource-limited setting. The uniqueness of this trial, compared to other ongoing randomized trials, includes the PTV margins and the xerostomia assessment by scintigraphy at 12 months as the primary endpoint. • The ReSTART, trial, evaluates the efficacy of adaptive radiotherapy in reducing xerostomia for HNSCC. • In the adaptive RT arm, two pre-planned adaptive planning are done at 10 and 20 fractions. • The CTV to PTV margin in the adaptive RT arm is 3 mm. • Primary hypothesis is a 25% benefit of 1-year salivary function, which is assessed by salivary scintigraphy. [ABSTRACT FROM AUTHOR]

For high-risk neuroblastoma, planning target volume coverage is often compromised to respect adjacent kidney tolerance. This trial investigated whether intensity-modulated arc radiotherapy techniques (IMAT) could facilitate dose escalation better than conventional techniques. Children with high-risk abdominal neuroblastoma referred for radiotherapy to the primary tumour site and involved regional lymph nodes were randomised to receive either standard dose (21 Gy in 14 fractions) or escalated dose (36 Gy in 24 fractions) radiotherapy. Dual planning with both a conventional anterior-posterior parallel opposed pair radiotherapy technique and an IMAT technique was performed. The quality of target volume and organ-at-risk delineation, and dosimetric plans, were externally reviewed. Dosimetric parameters were used to judge the superior technique for treatment. This feasibility trial was not powered to detect improvement in outcome with dose escalation. Between 2017 and 2020, 50 patients were randomised and dual-planned. The IMAT technique was judged more favourable in 48 patients. In all patients randomised to receive 36 Gy, IMAT would have permitted delivery of the full dose (median D50% 36.0 Gy, inter-quartile range 36.0–36.1 Gy) to the target volume, whereas dose compromise would have been required with conventional planning (median D50% 35.6 Gy, inter-quartile range 28.7–35.9 Gy). IMAT facilitates safe dose escalation to 36 Gy in patients receiving radiotherapy for neuroblastoma. The value of dose escalation is now being evaluated in a current prospective phase III randomised trial. • The standard tumour bed radiotherapy dose used for neuroblastoma is 21 Gy. • The optimal dose is uncertain, and a higher dose may lead to better local control. • Organ-at-risk tolerance may limit the desired dose to the target volume. • Intensity-modulated arc therapy facilitates better delivery of higher doses. [ABSTRACT FROM AUTHOR]

In recent years, the intersection of the academic and medical domains has increasingly spotlighted the utilization of biomaterials in radioactive disease treatment and radiation protection. Biomaterials, distinguished from conventional molecular pharmaceuticals, offer a suite of advantages in addressing radiological conditions. These include their superior biological activity, chemical stability, exceptional histocompatibility, and targeted delivery capabilities. This review comprehensively delineates the therapeutic mechanisms employed by various biomaterials in treating radiological afflictions impacting the skin, lungs, gastrointestinal tract, and hematopoietic systems. Significantly, these nanomaterials function not only as efficient drug delivery vehicles but also as protective agents against radiation, mitigating its detrimental effects on the human body. Notably, the strategic amalgamation of specific biomaterials with particular pharmacological agents can lead to a synergistic therapeutic outcome, opening new avenues in the treatment of radiation- induced diseases. However, despite their broad potential applications, the biosafety and clinical efficacy of these biomaterials still require in-depth research and investigation. Ultimately, this review aims to not only bridge the current knowledge gaps in the application of biomaterials for radiation-induced diseases but also to inspire future innovations and research directions in this rapidly evolving field. [Display omitted] [ABSTRACT FROM AUTHOR]

DNA-dependent protein kinase (DNA-PK) plays a key role in the repair of DNA double strand breaks via nonhomologous end joining. Inhibition of DNA-PK can enhance the effect of DNA double strand break inducing anticancer therapies. Peposertib (formerly "M3814") is an orally administered, potent, and selective small molecule DNA-PK inhibitor that has demonstrated radiosensitizing and antitumor activity in xenograft models and was well-tolerated in monotherapy. This phase 1 trial (National Clinical Trial 02516813) investigated the maximum tolerated dose, recommended phase 2 dose (RP2D), safety, and tolerability of peposertib in combination with palliative radiation therapy (RT) in patients with thoracic or head and neck tumors (arm A) and of peposertib in combination with cisplatin and curative-intent RT in patients with squamous cell carcinoma of the head and neck (arm B). Patients received peposertib once daily in ascending dose cohorts as a tablet or capsule in combination with palliative RT (arm A) or in combination with intensity modulated curative-intent RT and cisplatin (arm B). The most frequently observed treatment-emergent adverse events were radiation skin injury, fatigue, and nausea in arm A (n = 34) and stomatitis, nausea, radiation skin injury, and dysgeusia in arm B (n = 11). Based on evaluations of dose-limiting toxicities, tolerability, and pharmacokinetic data, RP2D for arm A was declared as 200 mg peposertib tablet once daily in combination with RT. In arm B (n = 11), 50 mg peposertib was declared tolerable in combination with curative-intent RT and cisplatin. However, enrollment was discontinued because of insufficient exposure at that dose, and the RP2D was not formally declared. Peposertib in combination with palliative RT was well-tolerated up to doses of 200 mg once daily as tablet with each RT fraction. When combined with RT and cisplatin, a tolerable peposertib dose yielded insufficient exposure. [ABSTRACT FROM AUTHOR]

To compare characteristics and outcomes in patients who had radiotherapy (RT) for prostate cancer (PCa) and underwent urinary diversion (UD) due to prostatic fistula (Fistula) vs localized radiation injury (Localized). This study was a retrospective single-institution study. Exclusion criteria included follow-up <3 months, large pelvic tumor, and surgery for cancer control. The Fistula group included fistulization outside of the urinary tract (rectal, soft tissue, thigh, pubic symphysis, and extensive necrosis surrounding the prostate). The group Localized had a multitude of problems; however, all were confined to the urinary tract. Patient characteristics, perioperative variables, and outcomes were compared between groups. Sixty-nine patients were included and had UD from 2009-2022. Median age and time from RT to UD were 73 (interquartile range (IQR) 67.9, 78.1) and 7.3 (IQR 3.2, 12.5) years. There were 29 (42%) and 40 (58%) patients in the Fistula and Localized groups. The Fistula group had a higher rate of abdominal/perineal approach (62.1% vs 12.5%, P <.001), a lower rate of right colon pouch (17.2% vs 40%, P =.043), and a longer operative time (515.7 vs 414.2 minutes, P =.017). Clavien-Dindo complications ≥3 were higher in the Fistula group (44.8% vs 20%, P =.027), including a higher rate of re-operation for recurrent pelvic abscess (37.9% vs 5%, P <.001). Survival for the cohort was 85.5% and did not differ between groups. Patients with prostate fistula after RT for PCa undergoing UD had longer, more complex operations, and higher rates of complications, notably post-operative pelvic abscesses, compared to men with localized RT injury. Long-term survival was comparable in both groups. [ABSTRACT FROM AUTHOR]

To investigate the association of low-grade radiation injury (LGRI) and high-grade radiation injury (HGRI) following prostate cancer treatment with mental health diagnoses and therapy. A retrospective study of men diagnosed with prostate cancer who were treated with radiotherapy. Men were followed to assess for LGRI or HGRI using IBM MarketScan. Cohorts included: no injury (no-RI), LGRI, HGRI, and controls. Mental health diagnoses and related treatment (medication/therapy) were identified using ICD-10 codes, CPT codes, and national drug codes. A multivariable Cox proportional hazards model from time of radiation to first instance of mental health diagnosis was modeled against injury group, age, and comorbidities. Between 2011 and 2020 we identified 55,425 men who received radiotherapy for prostate cancer. 22,879 (41.3%) experienced a LGRI while 4128 (7.4%) experienced a HGRI. Prior to radiation therapy, mental health diagnoses were equally distributed across cohorts (P >.05). Every marker of mental health showed a step-wise increase in incidence from no-RI to LGRI to HGRI except for alcohol abuse. Use of mental health medications and therapy visits were slightly more likely in the LGRI and HGRI groups prior to radiation, however, this difference was greatly increased postradiation therapy. LGRI (HR 1.38; P <.001) and HGRI (HR 2.1; P <.001) were independently associated with an increased likelihood of mental health diagnoses. LGRI and HGRI following prostate cancer radiotherapy are associated with increased risk of mental health diagnosis, medication use, and therapy need compared to men who do not develop injuries. The most common mental health diagnoses were depression and anxiety. [ABSTRACT FROM AUTHOR]

Despite the breast being a mobile organ, there is currently no standard suitable immobilisation device to optimise radiotherapy for women with larger breasts treated after a wide local excision. The SuPPORT 4 All (S4A) bra was co-designed with patients and radiotherapy professionals. The purpose of this study was to test the feasibility of using the S4A bra in the existing breast cancer radiotherapy pathway. A randomised feasibility trial was conducted in a single institution; the primary feasibility endpoint was the recruitment of 50 participants. Efficacy endpoints were also tested, including assessment of skin reactions, dose to organs at risk and patient comfort. Fifty women were randomised to receive either standard radiotherapy with no immobilisation (control) or radiotherapy with the S4A bra (intervention). A separate planning study was undertaken on the cases randomised to receive the S4A bra. Participants in the intervention arm (S4A bra) underwent two planning computed tomography scans, one with the bra on and one without the bra; allowing direct comparison of organs at risk data for S4A bra versus no bra. All women who started radiotherapy wearing the S4A bra completed treatment with the bra; patient comfort did not change across the 3 weeks of treatment. Positional accuracy using the bra was comparable with existing published accuracy for methods without immobilisation. The mean ipsilateral lung doses showed some improvement when positioning with the S4A bra was compared with the no bra set-up (3.72 Gy versus 4.85 Gy for right-sided cases, 3.23 Gy versus 3.62 Gy for left-sided cases). The S4A bra is feasible to use in the radiotherapy pathway with good patient adherence. The S4A bra has potential to reduce dose to organs at risk (specifically ipsilateral lung dose) while maintaining good breast tissue coverage, and improved patient dignity, warranting further investigation on a larger scale. • The S4A bra is feasible to use in the breast cancer radiotherapy pathway. • In women with larger breasts, the S4A bra may reduce the mean ipsilateral lung dose. • The bra may allow greater breast coverage without increasing mean heart dose. • Patient compliance with use of the immobilisation bra was high. • Compliance with self-monitoring of skin reactions and breast changes was good. [ABSTRACT FROM AUTHOR]

The anti-inflammatory efficacy of radiation therapy (RT) with single fractions below 1.0 Gy has been demonstrated in Alzheimer's disease mouse models. As neuroinflammation is also a major pathological feature of Parkinson's disease (PD), RT may also be effective in PD treatment. Therefore, this study aimed to investigate the anti-inflammatory effect of low-moderate dose RT (LMDRT, 0.6 Gy/single dose, for 5 days) exposure in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 30 mg/kg, intraperitoneally, for 5 consecutive days)-induced PD mouse model. Importantly, LMDRT reduced the levels of glial fibrillary acidic protein and intercellular adhesion molecule-1 (CD54) in the striatum region, which increased following MPTP administration. LMDRT also modulated inflammatory gene expression patterns in the substantia nigra region of the MPTP-treated mice. However, LMDRT had no direct effects on the severe loss of dopaminergic neurons and impaired motor behavior in the rotarod test. These results indicate that LMDRT has anti-inflammatory effects by modulating neuroinflammatory factors, including glial fibrillary acidic protein and intercellular adhesion molecule-1, but showed no behavioral improvements or neuroprotection in the MPTP-induced mouse model of PD. [ABSTRACT FROM AUTHOR]

Compared with conventional dose rate irradiation (CONV), ultrahigh dose rate irradiation (UHDR) has shown superior normal tissue sparing. However, a clinically relevant widening of the therapeutic window by UHDR, termed "FLASH effect," also depends on the tumor toxicity obtained by UHDR. Based on a combined analysis of published literature, the current study examined the hypothesis of tumor isoefficacy for UHDR versus CONV and aimed to identify potential knowledge gaps to inspire future in vivo studies. A systematic literature search identified publications assessing in vivo tumor responses comparing UHDR and CONV. Qualitative and quantitative analyses were performed, including combined analyses of tumor growth and survival data. We identified 66 data sets from 15 publications that compared UHDR and CONV for tumor efficacy. The median number of animals per group was 9 (range 3-15) and the median follow-up period was 30.5 days (range 11-230) after the first irradiation. Tumor growth assays were the predominant model used. Combined statistical analyses of tumor growth and survival data are consistent with UHDR isoefficacy compared with CONV. Only 1 study determined tumor-controlling dose (TCD 50) and reported statistically nonsignificant differences. The combined quantitative analyses of tumor responses support the assumption of UHDR isoefficacy compared with CONV. However, the comparisons are primarily based on heterogeneous tumor growth assays with limited numbers of animals and short follow-up, and most studies do not assess long-term tumor control probability. Therefore, the assays may be insensitive in resolving smaller response differences, such as responses of radioresistant tumor subclones. Hence, tumor cure experiments, including additional TCD 50 experiments, are needed to confirm the assumption of isoeffectiveness in curative settings. [ABSTRACT FROM AUTHOR]

Patients exposed to acute high doses of ionizing radiation are susceptible to dose-dependent bone marrow depression with resultant pancytopenia. Romiplostim (RP; Nplate) is a recombinant thrombopoietin receptor agonist protein that promotes progenitor megakaryocyte proliferation and platelet production and is an approved treatment for patients with chronic immune thrombocytopenia. The goal of our study was to evaluate the postirradiation survival and hematologic benefits of a single dose of RP with or without pegfilgrastim (PF; Neulasta, granulocyte colony stimulating factor) by conducting a well-controlled, treatment-concealed, good laboratory practice-compliant study in rhesus macaques that was compliant with the United States Food and Drug Administration Animal Rule regulatory approval pathway. Irradiated male and female rhesus macaques (20/sex in each of 3 groups: control, RP, and RP + PF) were subcutaneously administered vehicle or RP (5 mg/kg, 10 mL/kg) on day 1 in the presence or absence of 2 doses of PF (0.3 mg/kg, 0.03 mL/kg, days 1 and 8). Total body radiation (680 cGy, 50 cGy/min from cobalt-60 gamma ray source) occurred 24 ± 2 hours previously at a dose targeting 70% lethality for the control cohort over 60 days. The study examined 60-day survival postirradiation as the primary endpoint. Secondary endpoints included incidence, severity, and duration of thrombocytopenia and neutropenia, other hematology parameters, coagulation parameters, and body weight change to provide insights into potential mechanisms of action. Compared with sham-treated controls, treated animals demonstrated a 40% to 55% survival benefit compared with controls, less severe clinical signs, reduced incidence of thrombocytopenia and/or neutropenia, earlier hematologic recovery, and reduced morbidity from bacterial infection. These results were pivotal in obtaining Food and Drug Administration approval in January 2021 for RP's new indication as a single administration therapy to increase survival in adults and pediatric patients acutely exposed to myelosuppressive doses of radiation. [ABSTRACT FROM AUTHOR]

To evaluate the healthcare resource impact of radiation injury following prostate cancer treatment. Using IBM MarketScan, we performed a retrospective study of men with prostate cancer who were treated with radiotherapy and subsequently developed low-grade (LGRI) and high-grade radiation injury (HGRI). Radiation injury diagnoses included bladder neck stenosis, hematuria/cystitis, fistula, ureteral stricture, and incontinence. LGRI and HGRI included injury diagnosis without intervention and with intervention, respectively. Health care visits and costs were measured over 5 time periods including 2 years before radiation, 1 year before radiation, radiation to injury diagnosis, injury diagnosis to first intervention (LGRI), and following first intervention (HGRI). Negative binomial regression modeling was used to assess the effect of radiation injury on average cost adjusting for demographics and comorbidities. Between 2008 and 2017, we identified 121,027 men who received radiotherapy following prostate cancer diagnosis of which 10,057 (8.3%) experienced a HGRI. The frequency of urologic visits and average costs were similar in those without injury and LGRI. However, men with HGRI experienced higher visit frequency and monthly costs. Amongst high-grade injuries, urinary fistula had the highest frequency of visit utilization at 378 visits before first intervention and 245 visits after first intervention. Following radiation injury diagnosis, the average monthly cost was twice as high in those with HGRI ($85.78) compared to LGRI ($38.66). HGRI was associated with increased urologic health care use and average monthly cost when compared to those who experienced LGRI or no injury. Urinary fistula was associated with the largest resource burden. [ABSTRACT FROM AUTHOR]

Currently, there is no effective treatment for chronic skin radiation injury, which burdens patients significantly. Previous studies have shown that cold atmospheric plasma has an apparent therapeutic effect on acute and chronic skin injuries in clinical. However, whether CAP is effective for radiation-induced skin injury has not been reported. We created 35Gy X-ray radiation exposure within 3 * 3 cm2 region of the left leg of rats and applied CAP to the wound bed. Wound healing, cell proliferation and apoptosis were examined in vivo or vitro. CAP alleviated radiation-induced skin injury by enhancing proliferation and migration and cellular antioxidant stress and promoting DNA damage repair through regulated nuclear translocation of NRF2. In addition, CAP inhibited the proinflammatory factors' expression of IL-1β, TNF-α and temporarily increased the pro repair factor's expression of IL-6 in irradiated tissues. At the same time, CAP also changed the polarity of macrophages to a repair-promoting phenotype. Our finding suggested that CAP ameliorated radiation-induced skin injury by activating NRF2 and ameliorating the inflammatory response. Our work provided a preliminary theoretical foundation for the clinical administration of CAP in high-dose irradiated skin injury. [Display omitted] • CAP alleviates radiation-induced skin injury. • CAP increased antioxidants through nuclear translocation of NRF2. • CAP ameliorates the inflammatory in irradiated skin. [ABSTRACT FROM AUTHOR]

Victims of acute radiation exposure are susceptible to hematopoietic toxicity due to bone marrow damage and loss of mature blood elements. Here, we evaluated cord blood–derived endothelial progenitor cells (CB-EPCs) as a potential cellular therapy for mitigation of hematologic acute radiation syndrome. CB-EPCs express endothelial cell markers and maintain their growth characteristics beyond 10+ passages without diminishing their doubling capacity. Further, CB-EPCs can be cryopreserved in vapor-phase liquid nitrogen and easily recovered for propagation, making them an attractive nonimmunogenic cellular therapy for off-the-shelf use. Importantly, we show CB-EPCs have the capacity to potently expand adult human bone marrow hematopoietic progenitor cells both in vitro and in vivo. To demonstrate the role of CB-EPCs in promoting in vivo human immune reconstitution after irradiation, we employed a novel humanized mouse model established by transplant of CD34+ bone marrow cells from 9 unique adult organ donors into immunocompromised NSG-SGM3 mice. The response of the humanized immune system to ionizing irradiation was then tested by exposure to 1 Gy followed by subcutaneous treatment of CB-EPCs, Food and Drug Administration–approved growth factor pegfilgrastim (0.3 mg/kg), or saline. At day 7, total human bone marrow was decreased by 80% in irradiated controls. However, treatment with either growth factor pegfilgrastim or CB-EPCs increased recovery of total human bone marrow by 2.5-fold compared with saline. Notably, CB-EPCs also increased recovery of both human CD34+ progenitors by 5-fold and colony-forming capacity by 3-fold versus saline. Additionally, CB-EPCs promoted recovery of endogenous bone marrow endothelial cells as observed by both increased vessel area and length compared with saline. These findings indicate the feasibility of using humanized mice engrafted with adult bone marrow for radiation research and the development of CB-EPCs as an off-the-shelf cellular therapy for mitigation of hematologic acute radiation syndrome. [ABSTRACT FROM AUTHOR]

Skin brachytherapy represents an excellent alternative treatment for patients with non-melanoma skin cancers. It offers superior conformity of dose distribution with rapid dose fall off, reducing the risk of radiotherapy-related treatment toxicity. A smaller treatment volume in brachytherapy, when compared with external beam radiotherapy, is conducive for hypofractionation, which is an attractive option for decreasing outpatient visits to the cancer centre, especially for elderly and frail patients. Skin brachytherapy is an excellent option to preserve function and cosmesis, especially in skin cancers located in the head and neck region. Electronic brachytherapy, image-guided superficial brachytherapy and 3D printed moulds are all emerging advances in skin brachytherapy. [ABSTRACT FROM AUTHOR]

Comparative outcome data after intraoperative radiation therapy and whole breast irradiation (WBI) for breast cancer at >10 years median follow-up are rare. We present a mature, single-institution, matched-pair comparison reporting survival and relapse rates in patients treated with either modality. Complete data sets for 258 intraoperative electron radiation therapy (IOERT) patients treated between 2000 and 2010 were matched with 258 patients postoperatively treated with WBI by age/histology/tumor size, grading/lymph-node-status/hormone receptors/type of adjuvant therapy/surgical margins, and treatment date. Relapse at surgical intervention site was classified as true local recurrence (LR). All recurrences in the treated breast (any quadrant) were classified as ipsilateral recurrence (IR). Median follow-up was 157 months (12-251) for the IOERT group and 154 months (31-246) for the WBI group. Cumulative incidence of IR at 5, 10, and 15 years was 2.4%, 7.9%, and 12.7% for IOERT and 1.2%, 4.1%, and 5.0% for WBI (P =.02). Cumulative incidence of LR at 5, 10, and 15 years was 1.6%, 5.1%, and 8.3% for IOERT and 0.4%, 2.1%, and 2.5% for WBI (P =.02). No differences in overall survival, disease-free survival, second cancer incidence, or cardiac events were recorded in either treatment group. Outcome was better in the accelerated partial breast irradiation (APBI)-suitable group than in the APBI-unsuitable group (2009 criteria) (cumulative incidence of IR at 5, 10, and 15 years was 0% vs 7.3%, 6.1% vs 13.3%, and 7.3% vs 19.9% for IOERT and 0% vs 1.8%, 2.0% vs 3.9%, and 3.1% vs 3.9% for WBI) and in the revised APBI-suitable group than in the APBI-cautionary group (2017 criteria) (cumulative incidence of IR at 5, 10, and 15 years was 1.1% vs 6.4%, 6.2% vs 13.3%, and 7.8% vs 27.5% for IOERT and 1.7% vs 0%, 4.1% vs 4.4%, and 5.4% vs 4.4% for WBI). The IR and LR rate were higher after IOERT than after WBI for the American Society for Radiation Oncology suitable patient group, although without reaching statistical significance. Thus, IOERT could be an alternative to WBI upon stringent patient selection, but patients should be counseled carefully about the potential for increased IR rate with IOERT. Second cancer incidence and cardiac events did not differ between IOERT and WBI. [ABSTRACT FROM AUTHOR]

Biology-guided radiation therapy (BgRT) uses real-time line-of-response data from on-board positron emission tomography (PET) detectors to guide beamlet delivery during therapeutic radiation. The current workflow requires 18F-fluorodeoxyglucose (FDG) administration daily before each treatment fraction. However, there are advantages to reducing the number of tracer injections by using a PET tracer with a longer decay time. In this context, we investigated 89Zr-panitumumab (89Zr-Pan), an antibody PET tracer with a half-life of 78 hours that can be imaged for up to 9 days using PET. The BgRT workflow was evaluated preclinically in mouse colorectal cancer xenografts (HCT116) using small-animal positron emission tomography/computed tomography (PET/CT) for imaging and image-guided kilovoltage conformal irradiation for therapy. Mice (n = 5 per group) received 7 MBq of 89Zr-Pan as a single dose 2 weeks after tumor induction, with or without fractionated radiation therapy (RT; 6 × 6.6 Gy) to the tumor region. The mice were imaged longitudinally to assess the kinetics of the tracer over 9 days. PET images were then analyzed to determine the stability of the PET signal in irradiated tumors over time. Mice in the treatment group experienced complete tumor regression, whereas those in the control group were killed because of tumor burden. PET imaging of 89Zr-Pan showed well-delineated tumors with minimal background in both groups. On day 9 postinjection, tumor uptake of 89Zr-Pan was 7.2 ± 1.7 in the control group versus 5.2 ± 0.5 in the treatment group (mean percentage of injected dose per gram of tissue [%ID/g] ± SD; P =.07), both significantly higher than FDG uptake (1.1 ± 0.5 %ID/g) 1 hour postinjection. To assess BgRT feasibility, the clinical eligibility criteria was computed using human-equivalent uptake values that were extrapolated from preclinical PET data. Based on this semiquantitative analysis, BgRT may be feasible for 5 consecutive days after a single 740-MBq injection of 89Zr-Pan. This study indicates the potential of long-lived antibody-based PET tracers for guiding clinical BgRT. [ABSTRACT FROM AUTHOR]

FLASH radiation therapy (FLASH-RT) is a promising radiation technique that uses ultrahigh doses of radiation to increase the therapeutic window of the treatment. FLASH-RT has been observed to provide normal tissue sparing at high dose rates and similar tumor control compared with conventional RT, yet the biological processes governing these radiobiological effects are still unknown. In this study, we sought to investigate the potential immune response generated by FLASH-RT in a high dose of proton therapy in an orthotopic glioma rat model. We cranially irradiated rats with a single high dose (25 Gy) using FLASH dose rate proton irradiation (257 ± 2 Gy/s) or conventional dose rate proton irradiation (4 ± 0.02 Gy/s). We first assessed the protective FLASH effect that resulted in our setup through behavioral studies in naïve rats. This was followed by a comprehensive analysis of immune cells in blood, healthy tissue of the brain, and tumor microenvironment by flow cytometry. Proton FLASH-RT spared memory impairment produced by conventional high-dose proton therapy and induced a similar tumor infiltrating lymphocyte recruitment. Additionally, a general neuroinflammation that was similar in both dose rates was observed. Overall, this study demonstrated that FLASH proton therapy offers a neuro-protective effect even at high doses while mounting an effective lymphoid immune response in the tumor. [ABSTRACT FROM AUTHOR]

Radiotherapy for Hodgkin lymphoma leads to the irradiation of organs at risk (OAR), which may confer excess risks of late effects. Comparative dosimetry studies show that proton beam therapy (PBT) may reduce OAR irradiation compared with photon radiotherapy, but PBT is more expensive and treatment capacity is limited. The purpose of this study is to inform the appropriateness of PBT for intermediate-stage Hodgkin lymphoma (ISHL). A microsimulation model simulating the course of ISHL, background mortality and late effects was used to estimate comparative quality-adjusted life years (QALYs) lived and healthcare costs after consolidative pencil beam scanning PBT or volumetric modulated arc therapy (VMAT), both in deep-inspiration breath-hold. Outcomes were compared for 606 illustrative patients covering a spectrum of clinical presentations, varying by two age strata (20 and 40 years), both sexes, three smoking statuses (never, former and current) and 61 pairs of OAR radiation doses from a comparative planning study. Both undiscounted and discounted outcomes at 3.5% yearly discount were estimated. The maximum excess cost of PBT that might be considered cost-effective by the UK's National Institute for Health and Care Excellence was calculated. OAR doses, smoking status and discount rate had large impacts on QALYs gained with PBT. Current smokers benefited the most, averaging 0.605 undiscounted QALYs (range –0.341 to 2.171) and 0.146 discounted QALYs (range –0.067 to 0.686), whereas never smokers benefited the least, averaging 0.074 undiscounted QALYs (range –0.196 to 0.491) and 0.017 discounted QALYs (range –0.030 to 0.086). For the gain in discounted QALYs to be considered cost-effective, PBT would have to cost at most £4812 more than VMAT for current smokers and £645 more for never smokers. This is below preliminary National Health Service cost estimates of PBT over photon radiotherapy. In a UK setting, PBT for ISHL may not be considered cost-effective. However, the degree of unquantifiable uncertainty is substantial. • Proton beam therapy offers dosimetric advantage over photon radiotherapy. • Lifetime modelling needed to estimate comparative benefits and cost-effectiveness. • Baseline risks such as smoking increased quality adjusted survival benefit. • Proton beam therapy unlikely to be cost-effective in UK under NICE threshold. • There is a large amount of unquantifiable uncertainty when using modelling approach. [ABSTRACT FROM AUTHOR]

[Display omitted] • Intravenous injection of IVIg alone fights against radiation-induced hematopoietic and GI tract toxicity in female mice only. • Abdominal local irradiation induces a sex-specific gut microbiota configuration and small intestinal gene expression signature. • IVIg combined with Lachnospiraceae or hypoxanthine, a metabolite produced by Lachnospiraceae , mitigates radiation injuries in male mice. • Lachnospiraceae or hypoxanthine replenishment up-regulates radiation-decreased PLD1 expression in small intestine in male mice. In females, radiation exposure increases the intestinal PLD1, silencing PLD1 blunts the radioprotection of IVIg. • IVIg performs radioprotection in a sex-dependent manner through Lachnospiraceae /hypoxanthine/PLD1 axis. With the mounting number of cancer survivors, the complications following cancer treatment become novel conundrums and starve for countermeasures. Intravenous immunoglobulin (IVIg) is a purified preparation for immune-deficient and autoimmune conditions. Here, we investigated whether IVIg could be employed to fight against radiation injuries and explored the underlying mechanism. Hematopoietic or gastrointestinal (GI) tract toxicity was induced by total body or abdominal local irradiation. High-throughput sequencing was performed to analyze the gut microbiota configurations and gene expression profile of small intestine. The untargeted metabolomics of gut microbiome was assessed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses. Hydrodynamic-based gene delivery was used to knockdown the target genes in vivo. Intravenous injection of IVIg protected against radiation-induced hematopoietic and GI tract toxicity in female mice but not in males. IVIg structured sex-characteristic gut microbiota configurations in abdominal irradiated mice. The irradiation enriched gut Lachnospiraceae in female mice but reduced those in males. IVIg injection combined with oral gavage of Lachnospiraceae or its metabolite hypoxanthine, alleviated radiation toxicity in male mice however, Lachnospiraceae or hypoxanthine alone failed to ameliorate the injuries. Abdominal local irradiation drove sex-distinct gene expression signatures in small intestine. Mechanistic investigation showed that replenishment of Lachnospiraceae or hypoxanthine offset abdominal radiation-reduced PLD1 expression in male mice. In females, irradiation elevated PLD1 expression. Deletion of PLD1 in GI tract of female mice erased the radioprotective effects of IVIg. IVIg battles against radiation injuries in a sex-specific, gut microbiome-dependent way through Lachnospiraceae /hypoxanthine/PLD1 axis. Our findings provide a sex-precise therapeutic avenue to improve the prognosis of cancer patients with radiotherapy in pre-clinical settings. [ABSTRACT FROM AUTHOR]

Pelvic radiation therapy (RT) can cause debilitating bladder toxicities but few clinical interventions exist to prevent injury or alleviate symptoms. From a large genome-wide association study in patients with prostate cancer it was previously reported that SNPs tagging AGT, part of the renin-angiotensin system (RAS), correlated with patient-reported late hematuria, identifying a potential targetable pathway to prevent RT-induced bladder injury. To investigate this association, we performed a preclinical study to determine whether RAS modulation protected the bladder against RT injury. C57BL/6 male mice were treated with an oral angiotensin converting enzyme inhibitor (ACEi: 0.3g/L captopril) 5 days before focal bladder X-irradiation with either single dose (SD) 30 Gy or 3 fractions of 8 Gy (8 Gy × 3 in 5 days). RT was delivered using XStrahl SARRP Muriplan CT-image guidance with parallel-opposed lateral beams. ACEi was maintained for 20 weeks post RT. Bladder toxicity was assessed using assays to identify local injury that included urinalysis, functional micturition, bladder-released exosomes, and histopathology, as well as an assessment of systemic changes in inflammatory-mediated circulating immune cells. SD and fractionated RT increased urinary frequency and reduced the volume of individual voids at >14 weeks, but not at 4 weeks, compared with nonirradiated animals. Urothelial layer width was positively correlated with mean volume of individual voids (P =.0428) and negatively correlated with number of voids (P =.028), relating urothelial thinning to changes in RT-mediated bladder dysfunction. These chronic RT-induced changes in micturition patterns were prevented by captopril treatment. Focal bladder irradiation significantly increased the mean particle count of urine extracellular vesicles and the monocyte and neutrophil chemokines CCL2 and MIP-2, and the proportions of circulating inflammatory-mediated neutrophils and monocytes, which was also prevented by captopril. Exploratory transcriptomic analysis of bladder tissue implicated inflammatory and erythropoietic pathways. This study demonstrated that systemic modulation of the RAS protected against and alleviated RT-induced late bladder injury but larger confirmatory studies are needed. [ABSTRACT FROM AUTHOR]

Minibeam radiation therapy (MBRT) is an innovative technique that uses a spatial dose modulation. The dose distribution consists of high doses (peaks) in the path of the minibeam and low doses (valleys). The underlying biological mechanism associated with MBRT efficacy remains currently unclear and thus we investigated the potential role of the immune system after treatment with MBRT. Rats bearing an orthotopic glioblastoma cell line were treated with 1 fraction of high dose conventional radiation therapy (30 Gy) or 1 fraction of the same mean dose in MBRT. Both immunocompetent (F344) and immunodeficient (Nude) rats were analyzed in survival studies. Systemic and intratumoral immune cell population changes were studied with flow cytometry and immunohistochemistry (IHC) 2 and 7 days after the irradiation. The absence of response of Nude rats after MBRT suggested that T cells were key in the mode of action of MBRT. An inflammatory phenotype was observed in the blood 1 week after irradiation compared with conventional irradiation. Tumor immune cell analysis by flow cytometry showed a substantial infiltration of lymphocytes, specifically of CD8 T cells and B cells in both conventional and MBRT-treated animals. IHC revealed that MBRT induced a faster recruitment of CD8 and CD4 T cells. Animals that were cured by radiation therapy did not suffer tumor growth after reimplantation of tumoral cells, proving the long-term immunity response generated after a high dose of radiation. Our findings show that MBRT can elicit a robust antitumor immune response in glioblastoma while avoiding the high toxicity of a high dose of conventional radiation therapy. [ABSTRACT FROM AUTHOR]

To report the final results of a dose-escalation study of volumetric intensity-modulated arc stereotactic radiosurgery (VMAT-SRS) boost after three-dimensional conformal radiation therapy in patients with spine metastases. Oligometastatic cancer patients bearing up to five synchronous metastases (visceral or bone, including vertebral ones) and candidates for surgery or radiosurgery were considered for inclusion. 25 Gy was delivered in 10 daily fractions (2 weeks) to the metastatic lesion, affected vertebrae and adjacent ones (one cranial and one caudal vertebra). Sequentially, the dose to spinal metastases was progressively increased (8 Gy, 10 Gy, 12 Gy) in the patient cohorts. Dose-limiting toxicities were defined as any treatment-related non-hematologic acute adverse effects rated as grade ≥3 or any acute haematological toxicity rated as ≥ 4 by the Radiation Therapy Oncology Group scale. Fifty-two lesions accounting for 40 consecutive patients (male/female: 29/11; median age: 71 years; range 40–85) were treated from April 2011 to September 2020. Most patients had a primary prostate (65.0%) or breast cancer (22.5%). Thirty-two patients received 8 Gy VMAT-SRS boost (total BED α/β10 : 45.6 Gy), 14 patients received 10 Gy (total BED α/β10 : 51.2 Gy) and six patients received 12 Gy (total BED α/β10 : 57.6 Gy). The median follow-up time was over 70 months (range 2–240 months). No acute toxicities > grade 2 and no late toxicities > grade 1 were recorded. The overall response rate based on computed tomography/positron emission tomography–computed tomography/magnetic resonance was 78.8%. The 24-month actuarial local control, distant metastases-free survival and overall survival rates were 88.5%, 27.1% and 90.3%, respectively. A 12 Gy spine metastasis SRS boost following 25 Gy to the affected and adjacent vertebrae was feasible with an excellent local control rate and toxicity profile. • A dose-finding trial focused on spinal metastases treated with radiosurgery boost following conventional radiotherapy is presented. • According to this analysis, this combined approach is safe with no impact on quality of life. • Treating the affected and adjacent vertebrae boosting the lesion site led to an excellent local control rate. [ABSTRACT FROM AUTHOR]

Accurate assessment of radiation-induced breast toxicity is crucial for the management of breast radiation therapy (RT). Standard assessment of breast toxicity based on clinicians' visual inspection and palpation has considerable inter- and intra-observer variability. To overcome this challenge, we present an ultrasound histogram method that objectively evaluates radiation-induced breast toxicity longitudinally. In a prospective study, patients enrolled (n = 67) received ultrasound scans at four time points: prior to RT, last day of RT, 3-4 wk post-RT and 9-12-wk post-RT. Ultrasound scans were acquired at five locations (tumor bed and 3, 6, 9 and 12 o'clock) on both breasts. Two hundred sixty-four ultrasound scans and 2640 B-mode images were analyzed. The histogram differences between irradiated and contralateral breasts were calculated to evaluate radiation-induced breast changes. On the basis of the B-mode images, the severity of breast toxicity was graded as absent, mild, moderate or severe. The performance of the histogram method was assessed with the receiver operating characteristic (ROC) curve. The areas under the ROC curve ranged from 0.78 to 0.9 (sensitivity: 0.88-0.96, specificity: 0.53-0.83) at the lower quadrant for differentiating absent/mild from moderate/severe toxicity at various time points. This study provides preliminary evidence that ultrasound histogram differences can serve as an imaging biomarker to longitudinally assess radiation-induced acute toxicity. [ABSTRACT FROM AUTHOR]

• Dose–response relationship between breast induration and breast volume irradiated to 40 Gy. • Irradiated breast volume was significantly smaller with PBI compared to WBI. • No difference was found between the whole breast volumes in the two treatment arms. The relation between breast induration grade 2–3 at 3 years after radiation therapy and irradiated breast volume was investigated for patients in the Danish Breast Cancer Group (DBCG) Partial Breast Irradiation (PBI) trial. METHODS Treatment plan data was obtained from the Danish radiotherapy plan database. Dosimetric parameters for breast and organs at risk were determined. Breast induration data was obtained from the DBCG database. The volume of the whole breast (CTVp_breast) treated to various dose levels was determined for treatment plans in both arms. Logistic regression was used to assess the frequency of induration on breast volume irradiated to ≥40 Gy. RESULTS PBI and WBI was given to 433 and 432 patients, respectively. Median and interquartile ranges (IQR) for CTVp_breast were 710 mL (467–963 mL; PBI) and 666 mL (443–1012 mL; WBI) (p = 0.98). Median and IQR for CTVp_breast treated to ≥40 Gy was 24.9% (18.6–32.6%; PBI) and 59.8% (53.6–68.5%; WBI). Grade 2–3 induration was observed in 5% (PBI) and 10% (WBI) of the patients. A dose–response relationship was established between irradiated breast volume and frequency of breast induration. From the model, 5% and 10% risks of breast induration were observed for ≥40 Gy delivered to CTVp_breast volumes of 177 mL (95%CI, 94–260 mL) and 426 mL (95%CI, 286–567 mL), respectively. CONCLUSION The frequency of breast induration increased significantly with increasing irradiated breast volume, strongly favouring small volumes and PBI. Thus, treated breast volume – not the breast size itself - is the risk factor for induration. This is the first report directly linking the 40 Gy irradiated breast volume to breast induration. [ABSTRACT FROM AUTHOR]

To use pre-treatment magnetic resonance imaging-based radiomics data with clinical data to predict radiation-induced temporal lobe injury (RTLI) in nasopharyngeal carcinoma (NPC) patients with stage T4/N0–3/M0 within 5 years after radiotherapy. This study retrospectively examined 98 patients (198 temporal lobes) with stage T4/N0–3/M0 NPC. Participants were enrolled into a training cohort or a validation cohort in a ratio of 7:3. Radiomics features were extracted from pre-treatment magnetic resonance imaging that were T1-and T2-weighted. Spearman rank correlation, the t -test and the least absolute shrinkage and selection operator (LASSO) algorithm were used to select significant radiomics features; machine-learning models were used to generate radiomics signatures (Rad-Scores). Rad-Scores and clinical factors were integrated into a nomogram for prediction of RTLI. Nomogram discrimination was evaluated using receiver operating characteristic analysis and clinical benefits were evaluated using decision curve analysis. Participants were enrolled into a training cohort (n = 139) or a validation cohort (n = 59). In total, 3568 radiomics features were initially extracted from T1-and T2-weighted images. Age, D max , D 1cc and 16 stable radiomics features (six from T1-weighted and 10 from T2-weighted images) were identified as independent predictive factors. A greater Rad-Score was associated with a greater risk of RTLI. The nomogram showed good discrimination, with a C-index of 0.85 (95% confidence interval 0.79–0.92) in the training cohort and 0.82 (95% confidence interval 0.71–0.92) in the validation cohort. We developed models for the prediction of RTLI in patients with stage T4/N0–3/M0 NPC using pre-treatment radiomics data and clinical data. Nomograms from these pre-treatment data improved the prediction of RTLI. These results may allow the selection of patients for earlier clinical interventions. • Interdisciplinary study that used pre-treatment MRI-based radiomics data for RTLI prediction in NPC patients. • Only included patients with stage T4/N0-3/M0 NPC, making the study more targeted. • Provide reliable risk stratification of RTLI by using non-invasive radiomics and clinical data. • Radiomics information was extracted from the routine MRI examinations without increasing healthcare costs. [ABSTRACT FROM AUTHOR]

Background: The standard preoperative radiotherapy regimen of 50 Gy delivered in 25 fractions for 5 weeks for soft tissue sarcomas results in excellent local control, with major wound complications occurring in approximately 35% of patients. We aimed to investigate the safety of a moderately hypofractionated, shorter regimen of radiotherapy, which could be more convenient for patients.Methods: This single-centre, open-label, single-arm, phase 2 trial (HYPORT-STS) was done at a single tertiary cancer care centre (MD Anderson Cancer Center, Houston, TX, USA). We administered preoperative radiotherapy to a dose of 42·75 Gy in 15 fractions of 2·85 Gy/day for 3 weeks (five fractions per week) to adults (aged ≥18 years) with non-metastatic soft tissue sarcomas of the extremities or superficial trunk and an Eastern Cooperative Oncology Group performance status of 0-3. The primary endpoint was a major wound complication occurring within 120 days of surgery. Major wound complications were defined as those requiring a secondary operation, or operations, under general or regional anaesthesia for wound treatment; readmission to the hospital for wound care; invasive procedures for wound care; deep wound packing to an area of wound measuring at least 2 cm in length; prolonged dressing changes; repeat surgery for revision of a split thickness skin graft; or wet dressings for longer than 4 weeks. We analysed our primary outcome and safety in all patients who enrolled. We monitored safety using a Bayesian, one-arm, time-to-event stopping rule simulator comparing the rate of major wound complications at 120 days post-surgery among study participants with the historical rate of 35%. This trial is registered with ClinicalTrials.gov, NCT03819985, recruitment is complete, and follow-up continues.Findings: Between Dec 18, 2018, and Jan 6, 2021, we assessed 157 patients for eligibility, of whom 120 were enrolled and received hypofractionated preoperative radiotherapy. At no time did the stopping rule computation indicate that the trial should be stopped early for lack of safety. Median postoperative follow-up was 24 months (IQR 17-30). Of 120 patients, 37 (31%, 95% CI 24-40) developed a major wound complication at a median time of 37 days (IQR 25-59) after surgery. No patient had acute radiation toxicity (during radiotherapy or within 4 weeks of the radiotherapy end date) of grade 3 or worse (Common Terminology Criteria for Adverse Events [CTCAE] version 4.0) or an on-treatment serious adverse event. Four (3%) of 115 patients had late radiation toxicity (≥6 months post-surgery) of at least grade 3 (CTCAE or Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme): femur fractures (n=2), lymphoedema (n=1), and skin ulceration (n=1). There were no treatment-related deaths.Interpretation: Moderately hypofractionated preoperative radiotherapy delivered to patients with soft tissue sarcomas was safe and could therefore be a more convenient alternative to conventionally fractionated radiotherapy. Patients can be counselled about these results and potentially offered this regimen, particularly if it facilitates care at a sarcoma specialty centre. Results on long-term oncological, late toxicity, and functional outcomes are awaited.Funding: The National Cancer Institute. [ABSTRACT FROM AUTHOR]

Urinary toxicity is common following pelvic radiotherapy and can have a substantial negative effect on survivorship. Due to its prevalence and the increasing number of related clinical trials, localised prostate cancer radiotherapy is a useful illustrative tool to explore urinary toxicity. A good understanding of the interplay between anatomy, radiation-sensitive cell populations, and treatment sequencing is necessary for optimal outcomes. Emerging evidence suggests that the prostatic urethra is a radiation-sensitive structure, not only for stricture development, but also chronic irritative symptoms. Tools now exist not only to identify the urethra, but also to direct radiation dose away from the urethra, with early data suggesting that this reduces moderate-to-severe late urinary toxicity. Coupled with new evidence supporting dominant nodule microboosting and ultrahypofractionation as emerging standards of care, urethral sparing radiotherapy is a powerful tool against radiation induced urinary toxicity while also maximising disease control. [ABSTRACT FROM AUTHOR]

Purpose: In patients with recurrent or metastatic cervical cancer, the median survival time is 13 to 24 months based on the choice of palliative systemic chemotherapy. Evolving evidence suggests that the addition of radiation may lead to improved survival.Methods and Materials: Consecutive patients treated with radiation with or without systemic chemotherapy for oligometastatic or oligorecurrent disease within the period from 2017 to 2020 were included. All patients received systemic chemotherapy consultation and radiation to relapsed or metastatic sites. Progression-free survival (PFS) was determined as the period between diagnosis of relapse or metastasis and the last progression of the disease. Overall survival (OS) was defined as the time between the date of diagnosis of relapse or metastasis and follow-up or death. The effect of various prognostic and predictive factors was estimated using the Kaplan-Meier method and log-rank test.Results: Fifty-eight consecutive patients were included. The median time to relapse was 18 months (8-205 months). At the time of first relapse, 34.4% of patients (n = 20) had locoregional relapse, 32.8% (n = 19) had distant nodal metastases, and 32.8% (n = 19) had visceral metastases. The relapse was within previously irradiated portals in 34.5% (n = 20), out of field in 50% (n = 29), and both in 15.5% (n = 9) of patients. Overall, 56% of patients (n = 33) received systemic chemotherapy. The radiation therapy dose in equivalent doses of 2 Gy at the time of retreatment was 44 Gy (31-68 Gy). The median PFS and OS from the date of first relapse were 16 (12-19) and 28 months (2-108), respectively. Grade ≥3 toxicity was observed in 19% of patients. No patient- or treatment-related factor was identified as predictive of OS on univariate analysis.Conclusions: The use of potentially radical doses of radiation, including reirradiation at locoregional or distant oligorelapse or metastasis, is associated with encouraging PFS and OS in patients with cervical cancer. [ABSTRACT FROM AUTHOR]

Purpose: We retrospectively evaluated outcomes after radiation therapy for patients with oligoprogression on immune checkpoint inhibitors (ICI).Methods and Materials: We identified patients irradiated to ≤5 progressive lesions while receiving ICI between 2010 and 2020. We excluded patients whose systemic therapy was switched after radiation but before progression. We evaluated predictors of local control (LC), progression-free survival (PFS) and overall survival (OS).Results: We screened 1423 patients and identified 120 who were eligible; the most common histologies were lung cancer (n = 59) and melanoma (n = 36). The median number of oligoprogressive lesions was 1. For the median LC of irradiated oligoprogressive lesions, PFS and OS were not reached at 6.41 (4.67-7.66) and 29.80 (22.54-43.33) months, respectively. Tumor histology, radiated site, or radiation modality were not associated with LC, PFS, or OS. Local response to radiation (P < .0001) and radiation of newly developed lesions (P = .02) were associated with LC. Predictors of PFS on univariate and multivariate analyses were best response to radiation (P = .006) and high programmed death ligand 1 tumor proportion score (P = .02). On multivariate analyses, OS was associated with cumulative oligoprogressive lesion volumes (P = .02) and duration of ICI before oligoprogression (P = .03).Conclusions: Promising outcomes were observed among patients irradiated for oligoprogression on ICI, especially those with a favorable local response, high tumor programmed death ligand 1 expression, and those receiving ICI for longer periods before oligoprogression. These data can help identify patients well suited for radiation therapy versus those who should switch systemic treatment. [ABSTRACT FROM AUTHOR]

Purpose: Synchrotron-generated microbeam radiation therapy (MRT) represents an innovative preclinical type of cancer radiation therapy with an excellent therapeutic ratio. Beyond local control, metastatic spread is another important endpoint to assess the effectiveness of radiation therapy treatment. Currently, no data exist on an association between MRT and metastasis. Here, we evaluated the ability of MRT to delay B16F10 murine melanoma progression and locoregional metastatic spread.Methods and Materials: We assessed the primary tumor response and the extent of metastasis in sentinel lymph nodes in 2 cohorts of C57BL/6J mice, one receiving a single MRT and another receiving 2 MRT treatments delivered with a 10-day interval. We compared these 2 cohorts with synchrotron broad beam-irradiated and nonirradiated mice. In addition, using multiplex quantitative platforms, we measured plasma concentrations of 34 pro- and anti-inflammatory cytokines and frequencies of immune cell subsets infiltrating primary tumors that received either 1 or 2 MRT treatments.Results: Two MRT treatments were significantly more effective for local control than a single MRT. Remarkably, the second MRT also triggered a pronounced regression of out-of-radiation field locoregional metastasis. Augmentation of CXCL5, CXCL12, and CCL22 levels after the second MRT indicated that inhibition of melanoma progression could be associated with increased activity of antitumor neutrophils and T-cells. Indeed, we demonstrated elevated infiltration of neutrophils and activated T-cells in the tumors after the second MRT.Conclusions: Our study highlights the importance of monitoring metastasis after MRT and provides the first MRT fractionation schedule that promotes local and locoregional control with the potential to manage distant metastasis. [ABSTRACT FROM AUTHOR]

Purpose: The majority of cancer-related deaths are attributed to metastasis rather than localized primary tumor progression. However, the factors that regulate the premetastatic niche (PMN) and metastasis have not yet been clearly elucidated. We investigated the antimetastatic effects of irradiated tumor cell-derived microparticles (RT-MPs) and highlighted the role of innate immune cells in PMN formation.Methods and Materials: Mice were treated 3 times with isolated RT-MPs, followed by tumor cell injection via the tail vein. The hematoxylin and eosin staining was performed to assess the number of tumor nodules in the lungs, and in vivo luciferase-based noninvasive bioluminescence imaging was conducted to detected tumor burden. The mechanisms of RT-MPs mediated PMN formation was evaluated using flow cytometry, transwell assay, and reverse transcription-polymerase chain reaction.Results: RT-MPs inhibited tumor cell colonization in the lungs. Neutrophils phagocytosed RT-MPs and secreted CCL3 and CCL4, which induced monocytes chemotaxis and maturation into macrophages. RT-MPs promoted the transition of neutrophils and macrophages into antitumor phenotypes, hence inhibiting cancer cell colonization and proliferation.Conclusions: RT-MPs inhibited PMN formation and lung metastasis in a neutrophil- and macrophage-dependent but T cell-independent manner. [ABSTRACT FROM AUTHOR]

Purpose: Patient-reported outcomes provide quality of life (QOL) data during and after radiation. When pediatric patients are unable to complete patient-reported outcomes, it is unknown whether caregiver responses are an accurate surrogate. We assessed whether caregiver scores for the Pediatric Quality of Life Inventory (PedsQL) Core and Brain Tumor Module questionnaires can substitute for missing child scores.Methods and Materials: From 2016 to 2018, pediatric patients treated with radiation were followed in a prospective, institutional registry. Child and caregiver Core and Tumor PedsQL surveys were obtained at pretreatment, end of treatment, and in regular follow-up. The differences between the 2 scores at each time point were quantified using a linear mixed-model and the level of agreement was estimated with intraclass correlation coefficient (ICC). An ICC 95% confidence interval (CI) lower limit exceeding 0.75 was considered an acceptable threshold for using caregiver scores as imputed values for missing child scores.Results: Ninety-one children completed 403 surveys. Caregivers underestimated QOL scores at baseline, but not at end of treatment or any follow-up time. The PedsQL Core total score had an ICC of 0.88 (95% CI, 0.81-0.92), and the emotional, physical, school, and social function subdomain scores were 0.81 (0.72-0.88), 0.72 (0.58-0.82), 0.79 (0.68-0.86), and 0.75 (0.62-0.83), respectively. The tumor total score ICC was 0.91 (0.85, 0.94), and each of the subdomains (cognitive problems, communication, movement and balance, nausea, pain and hurt, perceived physical appearance, procedural anxiety, treatment anxiety, and worry) had ICC lower bound 95% CI ≥0.75 except for communication (0.83, 0.74-0.89). Bland-Altman analysis demonstrated no visual change in discrepancy between child and caregiver estimates as overall QOL improved.Conclusions: Agreement between child- and caregiver-reported QOL was generally strong in the acute period after radiation, implying that caregiver scores may be imputed for child scores in future protocols and analyses of pediatric QOL. [ABSTRACT FROM AUTHOR]

Purpose: The availability of validated biomarkers to assess radiation exposure and to assist in developing medical countermeasures remains an unmet need.Methods and Materials: We used a cobalt-60 γ-irradiated nonhuman primate (NHP) model to delineate a multiomics-based serum probability index of radiation exposure. Both male and female NHPs were irradiated with different doses ranging from 6.0 to 8.5 Gy, with 0.5 Gy increments between doses. We leveraged high-resolution mass spectrometry for analysis of metabolites, lipids, and proteins at 1, 2, and 6 days postirradiation in NHP serum.Results: A logistic regression model was implemented to develop a 4-analyte panel to stratify irradiated NHPs from unirradiated with high accuracy that was agnostic for all doses of γ-rays tested in the study, up to 6 days after exposure. This panel was comprised of Serpin family A9, acetylcarnitine, glycerophosphocholine (16:0/22:6), and suberylglycine, which showed 2- to 4-fold elevation in serum abundance upon irradiation in NHPs and can potentially be translated as a molecular diagnostic for human use after larger validation studies.Conclusions: Taken together, this study, for the first time, demonstrates the utility of a combinatorial molecular characterization approach using an NHP model for developing minimally invasive assays from small volumes of blood that can be effectively used for radiation exposure assessments. [ABSTRACT FROM AUTHOR]

• Local tumor control is the same with pencil beam scanning proton FLASH vs conventional dose rates. • Normal tissue effects assessed as acute skin damage and radiation induced fibrosis as endpoints. • Normal tissue sparing effect of FLASH demonstrated in the same animals as tumor control. • FLASH irradiation results in a dose modifying factor of 1.14 for fibrosis. • And a dose modifying factor of >1.30 for acute skin damage (moist desquamation). Preclinical studies indicate a normal tissue sparing effect when ultra-high dose rate (FLASH) radiation is used, while tumor response is maintained. This differential response has promising perspectives for improved clinical outcome. This study investigates tumor control and normal tissue toxicity of pencil beam scanning (PBS) proton FLASH in a mouse model. Tumor bearing hind limbs of non-anaesthetized CDF1 mice were irradiated in a single fraction with a PBS proton beam using either conventional (CONV) dose rate (0.33–0.63 Gy/s field dose rate, 244 MeV) or FLASH (71–89 Gy/s field dose rate, 250 MeV). 162 mice with a C3H mouse mammary carcinoma subcutaneously implanted in the foot were irradiated with physical doses of 40–60 Gy (8–14 mice per dose point). The endpoints were tumor control (TC) assessed as no recurrent tumor at 90 days after treatment, the level of acute moist desquamation (MD) to the skin of the foot within 25 days post irradiation, and radiation induced fibrosis (RIF) within 24 weeks post irradiation. TCD 50 (dose for 50% tumor control) was similar for CONV and FLASH with values (and 95% confidence intervals) of 49.1 (47.0–51.4) Gy for CONV and 51.3 (48.6–54.2) Gy for FLASH. RIF analysis was restricted to mice with tumor control. Both endpoints showed distinct normal tissue sparing effect of proton FLASH with MDD 50 (dose for 50% of mice displaying moist desquamation) of <40.1 Gy for CONV and 52.3 (50.0–54.6) Gy for FLASH, (dose modifying factor at least 1.3) and FD 50 (dose for 50% of mice displaying fibrosis) of 48.6 (43.2–50.8) Gy for CONV and 55.6 (52.5–60.1) Gy for FLASH (dose modifying factor of 1.14). FLASH had the same tumor control as CONV, but reduced normal tissue damage assessed as acute skin damage and radiation induced fibrosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • FLASH radiotherapy with carbon ions was demonstrated for the first time in vivo. • FLASH (100 Gy/s) reduced normal tissue toxicity and tumor growth. • FLASH irradiation reduces the number of lung metastases. The FLASH effect is a potential breakthrough in radiotherapy because ultra-high dose-rate irradiation can substantially widen the therapeutic window. While the normal tissue sparing at high doses and short irradiation times has been demonstrated with electrons, photons, and protons, so far evidence with heavy ions is limited to in vitro cell experiments. Here we present the first in vivo results with high-energy 12C-ions delivered at an ultra-high dose rate. LM8 osteosarcoma cells were subcutaneously injected in the posterior limb of female C3H/He mice 7 days before radiation exposure. Both hind limbs of the animals were irradiated with 240 MeV/n 12C-ions at ultra-high (18 Gy in 150 ms) or conventional dose rate (∼18 Gy/min). Tumor size was measured until 28 days post-exposure, when animals were sacrificed and lungs, limb muscles, and tumors were collected for further histological analysis. Irradiation with carbon ions was able to control the tumour both at conventional and ultra-high dose rate. FLASH decreases normal tissue toxicity as demonstrated by the reduced structural changes in muscle compared to conventional dose-rate irradiation. Carbon ion irradiation in FLASH conditions significantly reduced lung metastasis compared to conventional dose-rate irradiation and sham-irradiated animals. We demonstrated the FLASH effect in vivo with high-energy carbon ions. In addition to normal tissue sparing, we observed tumor control and a substantial reduction of lung metastasis in an osteosarcoma mouse model. [ABSTRACT FROM AUTHOR]

Patient factors affect the risk of radiotherapy toxicity, but many are poorly defined. Studies have shown that race affects cancer incidence, survival, drug response, molecular pathways and epigenetics. Effects on radiosensitivity and radiotherapy toxicity are not well studied. The aim of the present study was to identify the effects of race and ethnicity on the risk of radiotherapy toxicity. A systematic review was carried out of PubMed, Ovid Medline and Ovid Embase with no year limit. PRISMA 2020 guidelines were followed. Two independent assessors reviewed papers. Of 607 papers screened, 46 fulfilled the inclusion criteria. Papers were published between 1996 and 2021 and involved 30–28,354 individuals (median 433). Most involved patients with prostate (33%), breast (26%) and lung (9%) cancer. Both early and late toxicities were studied. Some studies reported a higher risk of toxicity in White men with prostate cancer compared with other races and ethnicities. For breast cancer patients, some reported an increased risk of toxicity in White women compared with other race and ethnic groups. In general, it was difficult to draw conclusions due to insufficient reporting and analysis of race and ethnicity in published literature. Reporting of race and ethnicity in radiotherapy studies must be harmonised and improved and frameworks are needed to improve the quality of reporting. Further research is needed to understand how ancestral heritage might affect radiosensitivity and risk of radiotherapy toxicity. • Ancestral heritage is likely to affect risk of some radiation toxicities. • Insufficient evidence from reviewing effects of race and ethnicity on toxicity. • Reporting race and ethnicity in radiation studies must be harmonised and improved. • Socioeconomic and comorbidity effects must be addressed. • Radiogenomic research needs diversifying beyond euro-centricity. [ABSTRACT FROM AUTHOR]

Diagnosis and management of aneurysmal subarachnoid hemorrhage (aSAH) depend heavily on imaging modalities that repeatedly expose patients to ionizing radiation. There is limited literature on cumulative radiation exposure in this patient population, which is a problem compounded by wide variation among institutions. The present study quantifies the cumulative cranial exposure to ionizing radiation resulting from diagnostic medical imaging and medical procedures during initial hospitalization for ruptured aSAH at a single academic institution and estimates the risk of future adverse events related to radiation injury. We performed a retrospective observational study of adults who presented to our institution during a nearly 3-year period with acute-onset aSAH, which was confirmed with diagnostic imaging, and had the aneurysm treated with either surgical clip ligation or endovascular embolization. A total of 131 patients met the inclusion criteria. Eighty-eight patients (67%) were treated with endovascular embolization and 43 (32%) were treated with clip ligation. We found the average radiation dose to the head during the incident hospitalization for aSAH to be 4.40 Gy (95% confidence interval, 3.91–4.89). Angiography and interventional radiology procedures accounted for most of this exposure. Most patients were exposed to levels of ionizing radiation that put them at considerable risk of deterministic radiation injury. Providers should be aware of the potential consequences of acute and long-term radiation exposure in this patient population, so they can monitor and counsel individuals accordingly and take steps to safely limit radiation exposure during aSAH management. [ABSTRACT FROM AUTHOR]

Spinal vertebral hemangiomas (SVHs) are the most common benign tumors of the spine. We performed a systematic review and meta-analysis of radiosurgery (RS) for SVHs. We reviewed articles published between January 1990 and December 2020 on PubMed. Tumor control, pain relief, and damage to surrounding tissues were evaluated with separate meta-analyses. This study was performed in accordance with the published Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 23 patients with 24 SVHs were reported in 3 studies. Follow-up time was 7.3–84 months. The vast majority of lesions were located at dorsal level (n = 18; 75%). In 20 (83.3%) patients, pain was the initial clinical presentation. Complete, partial, and stable responses after radiation were reported in 45.7% (P < 0.001), 23.6% (P = 0.02), and 37.2% (P = 0.7) of cases. Overall response was reported in 94.1% (P = 0.7). No progressive disease was reported. Pain relief was achieved in 87.5% of patients (P = 0.2). Damage to surrounding tissue caused by irradiation was reported in 22.3% (P = 0.02) of cases in 1 study, in which higher doses of radiation were delivered. Radiosurgery is safe and effective for SVHs. Pain relief after RS in symptomatic patients was extremely high, while no progressive disease was reported. Damage to surrounding tissues was reported in only 1 series and included osteitis, osteonecrosis, or soft tissue injury after higher radiation doses. [ABSTRACT FROM AUTHOR]

• ITLN1 shows promise in alleviating radiation-induced kidney damage. • Activation of the Akt/GSK-3β/Nrf2 pathway plays a key role in the protective mechanism. • ITLN1 overexpression improves renal function and reduces oxidative stress. • Cellular apoptosis, inflammation, senescence, and fibrosis are mitigated by ITLN1. • This study offers insights for potential therapeutic strategies against radiation-induced kidney injury. Radiation-induced kidney injury is a common side effect of radiotherapy, as the pelvic region is in close proximity to the kidneys, posing a risk of inducing radiation-induced kidney injury when treating any pelvic malignancies with radiotherapy. This type of injury typically manifests as chronic kidney disease a few months after radiotherapy, with the potential to progress to end-stage renal disease. Radiation-induced damage involves various components of the kidney, including glomeruli, tubules, interstitium, and extracellular matrix. Therefore, investigating its molecular mechanisms is crucial. In this study, we extensively searched literature databases, selecting recent transcriptomic studies related to acute kidney injury (AKI) published in the past decade. We downloaded the raw RNA sequencing datasets GSE30718 and GSE66494 related to AKI from the GEO database and identified that intestinal-type lectin ITLN1 plays a significant role in regulating radiation-induced kidney injury in rats. Differential gene analysis was performed using chip data from the GEO database, and further bioinformatics analysis identified 13 genes that may be involved in regulating kidney injury, with ITLN1 being the most relevant to kidney damage, thus selected as the target gene for this study. Subsequently, a rat model of radiation-induced kidney injury was established for experimental validation, assessing kidney tissue morphology and injury extent through staining observation and immunohistochemical staining. The protective effect of ITLN1 on kidney function was evaluated by measuring changes in rat body weight and blood pressure, serum kidney injury markers, and kidney structure. The experimental results indicate that overexpression of ITLN1 can improve kidney function in rats with radiation-induced kidney injury by activating the Akt/GSK-3β/Nrf2 signaling pathway, suppressing oxidative stress, cell apoptosis, inflammation, cellular senescence, and fibrosis. This study highlights the significant role of ITLN1 in regulating kidney injury, providing a novel target for future treatments of radiation-induced kidney injury. [ABSTRACT FROM AUTHOR]

Radiation therapy is a common treatment modality for patients with malignant tumors of the head and neck, chest and axilla. However, radiotherapy inevitably causes damage to normal tissues at the irradiated site, among which damage to the brachial plexus nerve(BP) is a serious adverse effect in patients receiving radiation therapy in the scapular or axillary regions, with clinical manifestations including abnormal sensation, neuropathic pain, and dyskinesia, etc. These adverse effects seriously reduce the living quality of patients and pose obstacles to their prognosis. Therefore, it is important to elucidate the mechanism of radiation induced brachial plexus injury (RIBP) which remains unclear. Current studies have shown that the pathways of radiation-induced BP injury can be divided into two categories: direct injury and indirect injury, and the indirect injury is closely related to the inflammatory response, microvascular damage, cytokine production and other factors causing radiation-induced fibrosis. In this review, we summarize the underlying mechanisms of RIBP occurrence and possible effective methods to prevent and treat RIBP. • This review summarizes the molecular mechanisms underlying radiation induced brachial plexus injury. • This review mainly introduces the oxidation mechanism and protective measures that mediate the occurrence of RIBP. • This article aims to provide guidance for radiation therapy for patients with neck and chest tumors. [ABSTRACT FROM AUTHOR]

Purpose: Due to its pivotal role in the modulation of immune and inflammatory responses, the gut microbiota has emerged as a key modulator of cancer treatment-induced gastrointestinal mucositis. However, it is not clear yet how it affects radiation therapy-induced oral mucositis (OM). As such, this study aimed to explore the gut microbiota's role in the pathogenesis of radiation-induced OM in rats.Methods and Materials: Male Sprague Dawley rats were treated with 20 Gy x-ray radiation (Rx) delivered to the snout, with or without antibiotic-induced microbiota depletion (AIMD). OM severity was assessed, and tongue tissues were collected on day 9 and 15 postradiation for tissue injury and inflammatory markers assessment.Results: AIMD+Rx had a significantly shorter duration of severe OM compared with Rx alone group. Macroscopically, the tongue ulcer-like area was smaller in AIMD+Rx compared with the Rx group. Microscopically, a smaller percentage of the mucosal ulcer was observed in the dorsal tongue of AIMD+Rx compared with the Rx group. AIMD+Rx also had significantly lower levels of interleukin 6, interleukin 1 beta, and toll like receptor 4 in the tongue tissues than the Rx group.Conclusions: The gut microbiota plays a role in OM pathogenesis, mainly in the recovery phase, through the modulation of proinflammatory pathways. Future microbiota-targeted interventions may improve OM in clinical settings. [ABSTRACT FROM AUTHOR]

Purpose: The treatment of radiation-induced brain injury (RI) caused by radiation therapy for head and neck cancer is challenging. Antiangiogenic therapy is a promising treatment. Apatinib is an oral tyrosine kinase inhibitor that selectively inhibits vascular endothelial growth factor receptor 2. We aimed to assess the efficacy and safety of apatinib in patients with RI.Methods and Materials: In this phase 2, open-label, single-arm, prospective study, we recruited patients aged 35 to 80 years with prior radiation therapy history for head and neck cancer who had newly diagnosed RI at the Sun Yat-sen Memorial Hospital, China. Apatinib was administered at a dosage of 250 mg once daily orally for 4 weeks. A Simon minimax 2-stage design was performed. The primary outcome was the proportion of patients with overall clinical efficacy, defined as a radiographic response of ≥25% reduction in baseline brain edema volume on magnetic resonance fluid attenuated inversion recovery images at week 4. Secondary end points were the overall improvement rate of brain necrosis, neurologic function, and safety.Results: We screened 37 patients, 36 of whom were enrolled between October 17, 2019, and August 3, 2020. At the cutoff date, 36 patients were assessed for efficacy and safety (19 were enrolled in stage 1 and 17 in stage 2). Of the 36 patients evaluated for overall clinical efficacy, 22 patients (61.1%; 95% CI, 43.5%-76.9%) achieved the primary end point at week 4. Among the 31 patients with brain necrosis lesions, 19 patients (61.3%; 95% CI, 42.2%-78.2%) showed improvement of brain necrosis. The most common grade 1 to 2 adverse events were hand-foot syndrome, fatigue, and hypertension There were no treatment-related grade 4 to 5 toxic effects.Conclusions: Oral apatinib shows promising efficacy and is well-tolerated in patients with RI. Further randomized controlled studies are warranted. [ABSTRACT FROM AUTHOR]

Purpose: Cancer is a severe delayed effect of acute radiation exposure. Total-body irradiation has been associated with an increased risk of solid cancer and leukemia in Japanese atomic bomb survivors, and secondary malignancies, such as sarcoma, are a serious consequence of cancer radiation therapy. The radiation late effects cohort (RLEC) of rhesus macaques (Macaca mulatta) is a unique resource of more than 200 animals for studying the long-term consequences of total-body irradiation in an animal model that closely resembles humans at the genetic and physiologic levels.Methods and Materials: Using clinical records, clinical imaging, histopathology, and immunohistochemistry, this retrospective study characterized the incidence of neoplasia in the RLEC.Results: Since 2007, 61 neoplasms in 44 of 239 irradiated animals were documented (18.4% of the irradiated population). Only 1 neoplasm was diagnosed among the 51 nonirradiated controls of the RLEC (2.0%). The most common malignancies in the RLEC were sarcomas (38.3% of diagnoses), which are rare neoplasms in nonirradiated macaques. The most common sarcomas included malignant nerve sheath tumors and malignant glomus tumors. Carcinomas were less common (19.7% of diagnoses), and consisted primarily of renal cell and hepatocellular carcinomas. Neoplasia occurred in most major body systems, with the skin and subcutis being the most common site (40%). RNA analysis showed similarities in transcriptional profiles between RLEC and human malignant nerve sheath tumors.Conclusions: This study indicates that total-body irradiation is associated with an increased incidence of neoplasia years following irradiation, at more than double the incidence described in aging, nonirradiated animals, and promotes tumor histotypes that are rarely observed in nonirradiated, aging rhesus macaques. [ABSTRACT FROM AUTHOR]

• Cardiac exposure from IMRT is similar to 3DCRT using current optimisation objectives. • More stringent IMRT cardiac sparing planning objectives may reduce cardiac exposure. • Consensus on contouring and Dose Volume Constraints for the heart is lacking. • Dose parameters reported for cardiac substructures, pericardium and the great vessels vary substantially. • Further heart sparing may be achieved using active respiratory motion management or particle beam therapy. Lung cancer radiotherapy increases the risk of cardiotoxicity and heart radiation dose is an independent predictor of poor survival. This study describes heart doses and strategies aiming to reduce exposure. A systematic review of lung cancer dosimetry studies reporting heart doses published 2013–2020 was undertaken. Doses were compared according to laterality, region irradiated, treatment modality (stereotactic ablative body radiotherapy (SABR) and non-SABR), planning technique, and respiratory motion management. For 392 non-SABR regimens in 105 studies, the average MHD was 10.3 Gy (0.0–48.4) and was not significantly different between left and right-sided tumours. It was similar between IMRT and 3DCRT (10.9 Gy versus 10.6 Gy) and lower with particle beam therapy (proton 7.0 Gy; carbon-ion 1.9 Gy). Active respiratory motion management reduced exposure (7.4 Gy versus 9.3 Gy). For 168 SABR regimens in 35 studies, MHD was 4.0 Gy (0.0–32.4). Exposure was higher in central and lower lobe lesions (6.3 and 5.8 Gy respectively). MHD was lowest for carbon ions (0.5 Gy) compared to other techniques. Active respiratory motion management reduced exposure (2.4 Gy versus 5.0 Gy). Delineation guidelines and Dose Volume Constraints for the heart varied substantially. There is scope to reduce heart radiation dose in lung cancer radiotherapy. Consensus on planning objectives, contouring and DVCs for the heart may lead to reduced heart doses in the future. For IMRT, more stringent optimisation objectives may reduce heart dose. Active respiratory motion management or particle therapy may be considered in situations where cardiac dose is high. [ABSTRACT FROM AUTHOR]

Objective: Human papilloma virus-negative oropharyngeal cancer has not achieved satisfactory outcomes compared with those of human papilloma virus-positive oropharyngeal cancer. This study evaluated the therapeutic efficacy of selective intraarterial chemoradiotherapy with the docetaxel and nedaplatin regimen for human papilloma virus-negative oropharyngeal cancer.Methods: Twenty-two consecutive patients with human papilloma virus-negative oropharyngeal cancer who had undergone selective intraarterial chemoradiotherapy were retrospectively analyzed. The primary tumor and whole neck were irradiated (50 Gy). Subsequently, the primary site and metastatic lymph nodes were boosted by 20 Gy. The intraarterial chemotherapy regimen comprised a combination of nedaplatin (80 mg/m2) and docetaxel (60 mg/m2), which was initially administered at the start of radiotherapy and was given every 4 weeks for three sessions. Each intraarterial dose of an anticancer agent was determined according to the percentage of the tumor volume supplied by the target artery to the total tumor volume, which was intraoperatively measured via cone-beam computed tomography. The outcome measures were locoregional control, disease-free survival, and overall survival rates and adverse events. Statistical analyses were performed using the Kaplan-Meier method.Results: The median follow-up period was 59 (range, 15-103) months. The T stage was T1/T2 in 5 patients (23%), T3 in 5 patients (23%), and T4 in 12 patients (54%). Cervical lymph node metastasis was staged as ≥N2c in 7 (32%) patients. Complete response was achieved in all patients at the first imaging examination after intraarterial chemoradiotherapy. The 5-year locoregional control, disease-free survival, and overall survival rates were 96% (95% confidence interval, 0.72-0.99), 91% (95% confidence interval, 0.68-0.98), and 100% (95% confidence interval, not available), respectively. Regarding serious acute adverse events, grade 4 laryngeal edema and leukopenia were observed in 1 (5%) and 11 patients (50%), respectively. No other serious acute adverse events were observed.Conclusion: Selective intraarterial chemoradiotherapy with docetaxel and nedaplatin has the potential to achieve favorable locoregional control, disease-free survival, and overall survival rates in human papilloma virus-negative oropharyngeal cancer. [ABSTRACT FROM AUTHOR]

Purpose: Radiation-induced lung injury is a major dose-limiting toxicity for thoracic radiation therapy patients. In experimental models, treatment with angiotensin converting enzyme (ACE) inhibitors mitigates radiation pneumonitis; however, the mechanism of action is not well understood. Here, we evaluate the direct role of ACE inhibition on lung immune cells.Methods and Materials: ACE expression and activity were determined in the lung immune cell compartment of irradiated adult rats after either high dose fractionated radiation therapy to the right lung (5 fractions × 9 Gy) or a single dose of 13.5 Gy partial body irradiation. Mitigation of radiation-induced pneumonitis with the ACE-inhibitor lisinopril was evaluated in the 13.5 Gy rat partial body irradiation model. During pneumonitis, we characterized inflammation and immune cell content in the lungs and bronchoalveolar lavage fluid. In vitro mechanistic studies were performed using primary human monocytes and the human monocytic THP-1 cell line.Results: In both the partial body irradiation and fractionated radiation therapy models, radiation increased ACE activity in lung immune cells. Treatment with lisinopril improved survival during radiation pneumonitis (P = .0004). Lisinopril abrogated radiation-induced increases in bronchoalveolar lavage fluid monocyte chemoattractant protein 1 (chemokine ligand 2) and MIP-1a cytokine levels (P < .0001). Treatment with lisinopril reduced both ACE expression (P = .006) and frequency of CD45+ CD11b+ lung myeloid cells (P = .004). In vitro, radiation injury acutely increased ACE activity (P = .045) and reactive oxygen species (ROS) generation (P = .004) in human monocytes, whereas treatment with lisinopril blocked radiation-induced increases in both ACE and ROS. Radiation-induced ROS generation was blocked by pharmacologic inhibition of either NADPH oxidase 2 (P = .012) or the type 1 angiotensin receptor (P = .013).Conclusions: These data demonstrate radiation-induced ACE activation within the immune compartment promotes the pathogenesis of radiation pneumonitis, while ACE inhibition suppresses activation of proinflammatory immune cell subsets. Mechanistically, our in vitro data demonstrate radiation directly activates the ACE/type 1 angiotensin receptor pathway in immune cells and promotes generation of ROS via NADPH oxidase 2. [ABSTRACT FROM AUTHOR]