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• Monocentric cohort of n = 223 recurrent glioma patients treated with re-irradiation. • Evaluation of re-irradiation dose escalation and concomitant therapy with bevacizumab (BEV) and temozolomide (TMZ) regarding post-recurrence survival and risk of radionecrosis. • Simultaneous integrated boost concept of 43.2 Gy feasible, effective and safe in this cohort. • Radionecrosis less frequent for concurrent BEV and post-recurrence survival benefit for concurrent TMZ treatment. • Basis for individualized selection of best concurrent therapy and optimal dose for re-irradiation. Re-irradiation (reRT) is an effective treatment modality for patients with recurrent glioma. Data on dose escalation, the use of simulated integrated boost and concomitant therapy to reRT are still scarce. In this monocentric cohort of n = 223 patients we investigated the influence of reRT dose escalation as well as the concomitant use of bevacizumab (BEV) with regard to post-recurrence survival (PRS) and risk of radionecrosis (RN). Patients with recurrent glioma treated between July 2008 and August 2022 with reRT with BEV, reRT with temozolomide (TMZ) and reRT without concomitant systemic therapy were retrospectively analyzed. PRS and RN-free survival (RNFS) were calculated for all patients using the Kaplan–Meier estimator. Univariable and multivariable cox regression was performed for PRS and for RNFS. The reRT Risk Score (RRRS) was calculated for all patients. Good, intermediate and poor risk of the RRRS translated into 11 months, 9 months and 7 months of median PRS (univariable: p = 0.008, multivariable: p = 0.013). ReRT was applied with a dose of ≤36 Gy (n = 140) or >36 Gy (n = 83). Concomitant bevacizumab (BEV) therapy was performed in n = 122 and concomitant temozolomide (TMZ) therapy in n = 32 patients. Median PRS was 10 months in patients treated with >36 Gy and 8 months in patients treated with ≤36 Gy (univariable: p = 0.032, multivariable: p = 0.576). Regarding concomitant TMZ therapy, median PRS was 14 months vs. 9 months for patients treated with or without TMZ (univariable: p = 0.041, multivariable: p = 0.019). No statistically significant influence on PRS was seen for concomitant BEV therapy in this series. RN was less frequent for reRT with concomitant BEV, (17/122; 13.9 %) than for reRT without BEV (30/101; 29.7 %). Regarding RNFS, the hazard ratio for reRT with BEV was 0.436 (univariable; p = 0.006) and 0.479 (multivariable; p = 0.023), respectively. ReRT dose did not show statistical significance in regards to RN (univariable: p = 0.073, multivariable: p = 0.404). RNFS was longer for patients receiving concomitant BEV to reRT than for patients treated with reRT only (mean 31.7 vs. 30.9 months, p = 0.004). In this cohort, in patients treated with concomitant BEV therapy RN was less frequently detected and in patients treated with concomitant TMZ longer PRS was observed. Based on these results, the best concomitant therapy and the optimal dose should be decided on a patient-by-patient basis. [ABSTRACT FROM AUTHOR]

Patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) have limited treatment options, particularly if they are transplantation or chimeric antigen receptor (CAR) T-cell ineligible, and novel therapeutics are needed. An 86-year-old woman with relapsed DLBCL received a novel, first-in-class small molecule inhibitor of N-myristoyltransferase (NMT) as the initial patient on a phase I dose escalation trial. Daily oral administration of 20 mg PCLX-001 tablets produced a pharmacokinetic profile suitable for single daily dosing: rapid oral absorption, followed by an apparent elimination half-life of 16 h, without systemic accumulation of drug by day 15. Pharmacodynamic tests showed no clear change in NMT1 and NMT2 levels or selected NMT substrate Lyn and HGAL protein levels in normal circulating blood mononuclear cells, suggesting a higher dose will be required for normal tissue toxicity. The patient did not experience any dose-limiting toxicities but had disease progression after 28 days of study therapy. Dose escalation continues in other patients in this first-in-human study of a new class of anticancer drug. We conclude that PCLX-001 oral monotherapy has suitable pharmacokinetic parameters for dose escalation, and that higher doses are required to achieve pharmacodynamic evidence of on-target activity in normal tissues. The current protocol is appropriately designed to achieve these ends, and the study proceeds without modification.

Abstract Background A significant proportion of patients with poor prognosis squamous cell cancer of the oropharynx relapse loco-regionally despite radical (chemo)radiotherapy. If a predictive biomarker for disease control can be identified during treatment then individualised and adaptive treatment strategies may be employed. The aim of this study is to assess the feasibility of adaptive and dose-escalated RT to the gross tumour volume without increasing surrounding planning target volume doses and maintaining clinically acceptable organs at risk doses. Materials and methods Twenty representative patients with poor prognosis locally advanced OPSCC who were known to have relapsed post RT, were re-planned retrospectively using Eclipse TPS v15.5, RapidPlan™ and multi-criteria optimisation. In our centre, PTV65 is treated with 65 Gy in 30 fractions while areas at risk of containing microscopic disease (PTV54) are treated synchronously to 54 Gy in 30 fractions. The original clinical plans were re-optimised to act as controls (Group I). These plans were split into two plans of 15 fractions each, with the latter 15 fractions used to escalate the dose to the GTV to 73 Gy (Group II) and 82 Gy (Group III). Plan sums were created for the total 30 fractions to record plan evaluation parameters along with assessments of plan deliverability. Results For all groups, the dose coverage at D98% and D50% for the PTVs were comparable. The D2% dose levels for PTV65-GTV increased. All dose levels associated with PTV54 remained largely unaffected by the dose escalation regimens. Conformity indices for PTV65 and PTVAll (PTV65 plus PTV54) reveal comparable target volume coverage across all three groups. Despite the GTV being escalated by 12.3% and 26.2% in groups II and III, the volume of GTV receiving > 84 Gy was considerably less than 1.75 cc. While OAR doses increased for the escalated groups, these increases were not clinically significant. Conclusion This planning feasibility study exploring RapidPlan™ combined with multi-criteria optimisation has demonstrated that doses to the GTV may be escalated without increasing PTV65-GTV, PTV54 or OAR doses considerably, suggesting an interventional clinical trial using this approach would be feasible.

Abstract Background Trametinib is an oral MEK 1/2 inhibitor, with a single agent recommended phase 2 dose (RP2D) of 2 mg daily (QD). This study was designed to evaluate RP2D, maximum tolerated dose (MTD), and pharmacokinetic (PK) profile of trametinib in patients with advanced solid tumors who had various degrees of hepatic dysfunction (HD). Methods Advanced cancer patients were stratified into 4 HD groups based on Organ Dysfunction Working Group hepatic function stratification criteria: normal (Norm), mild (Mild), moderate (Mod), severe (Sev). Dose escalation was based on “3 + 3” design within each HD group. PK samples were collected at cycle 1 days 15-16. Results Forty-six patients were enrolled with 44 evaluable for safety [Norm=17, Mild=7, Mod (1.5 mg)=4, Mod (2 mg)=5, Sev (1 mg)=9, Sev (1.5 mg)=2] and 22 for PK analysis. Treatment related adverse events were consistent with prior trametinib studies. No treatment related deaths occurred. Dose limiting toxicities (DLTs) were evaluable in 15 patients (Mild=6, Mod (1.5 mg)=3, Mod (2 mg)=2, Sev (1 mg)=3 and Sev (1.5 mg)=1). One DLT (grade 3 acneiform rash) was observed in a Sev patient (1.5 mg). Dose interruptions or reductions due to treatment related adverse events occurred in 15 patients (34%) [Norm=9, 53%; Mild=2, 29%; Mod (1.5 mg)=1, 33%; Mod (2 mg)=2, 33%; Sev (1 mg)=1, 11%; Sev (1.5 mg)=1; 50%]. There were no significant differences across HD groups for all PK parameters when trametinib was normalized to 2 mg. However, only limited PK data were available for the Mod (n = 3) and Sev (n = 3) groups compared to Norm (n = 10) and Mild (n = 6) groups. Trametinib is heavily protein bound, with no correlation between serum albumin level and unbound trametinib fraction (p = 0.26). Conclusions RP2D for trametinib in Mild HD patients is 2 mg QD. There are insufficient number of evaluable patients due to difficulty of patient accrual to declare RP2D and MTD for Mod and Sev HD groups. DLTs were not observed in the highest dose cohorts that reached three evaluable patients – 1.5 mg QD in Mod group, and 1 mg QD in Sev group. Trial registration This study was registered in the ClinicalTrials.gov website ( NCT 02070549 ) on February 25, 2014. .

Radiotherapy is the attractive treatment option for prostate cancer and has a clear role in all stages of the disease. Over the last decade, advances in technology, imaging capabilities, and improved radiobiological understanding have deeply transformed radiotherapy for prostate cancer, allowing dose escalation and wide adoption of hypofractionation. Furthermore, the integration of magnetic resonance imaging (MRI) and improved physical precision of dose delivery have given an impetus to additionally target intraprostatic tumor lesions, previously agnostic to conventional radiotherapy target definition concept. The emerging data from randomized clinical trials and observation research show that ultra-hypofractionation is a safe approach while further follow-up is needed to assess its efficacy compared to standard fractionation. There is an ongoing uncertainty surrounding true alpha/beta ratio for prostate cancer since hypofractionation has so far failed to yield theoretically envisioned superior biochemical control outcomes. Finally, recently published randomized trial settled ongoing controversy regarding the role of elective pelvic lymph node radiotherapy in patients with high-risk prostate cancer, showing clear benefit when pelvic nodes were treated to 50 Gy. The role of partial gland dose escalation/tumor boosting is evolving, and more data is needed to adopt this approach in routine clinical care. Going forward, molecular imaging will be crucial to assess biology of the disease, predict a response potentially, and optimally personalize radiotherapy treatment decisions. In this narrative review, we critically analyzed the published literature and provided practical summary of recent prostate radiotherapy advances for busy clinicians.

Abstract Background To explore the maximum tolerated dose (MTD) and evaluate the safety of dose escalation using hypofractionated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) concurrent with chemotherapy for unresectable stage III non-small cell lung cancer (NSCLC). Methods Four escalating radiation dose levels were used. This study included 25 patients with previously untreated NSCLC who received six concurrent weekly chemotherapy cycles comprising cisplatin and docetaxel. Dose-limiting toxicity (DLT) was defined as any acute toxicity that interrupted radiotherapy for more than 1 week. MTD was defined as the highest dose level that didn’t induce DLT or grade 5 toxicity in two patients. Results All 25 patients received the prescribed escalating radiation dose from the start dose up to LEVEL 4. Two patients experienced DLT at dose LEVEL 4. One patient died because of upper gastrointestinal hemorrhage within 6 months after radiotherapy, whereas another patient among the additional five patients died because of grade 5 radiation pneumonitis within 2 months after radiotherapy. Dose LEVEL 3 was defined as MTD. The 1- and 2-year local controls were 82.8 and 67.8%, respectively. The median progression-free survival was 15.4 months, whereas the median overall survival was 27.3 months. Conclusions Dose escalation was safely achieved up to LEVEL 3 [the planning gross target volume (PTVG) 60.5 Gy/22 Fx, 2.75 Gy/Fx; the planning clinical target volume (PTVC) 49.5 Gy/22 Fx] using SIB-IMRT concurrently with chemotherapy for unresectable stage III NSCLC, and the acute toxicities were generally well tolerated. Further prospective studies on long-term outcomes and late toxicities are warranted. Trial registration Retrospective registration, ChiCTR1900027290 (08/11/2019).

Abstract Background Modern designs for dose-finding studies (e.g., model-based designs such as continual reassessment method) have been shown to substantially improve the ability to determine a suitable dose for efficacy testing when compared to traditional designs such as the 3 + 3 design. However, implementing such designs requires time and specialist knowledge. Methods We present a practical approach to developing a model-based design to help support uptake of these methods; in particular, we lay out how to derive the necessary parameters and who should input, and when, to these decisions. Designing a model-based, dose-finding trial is demonstrated using a treatment within the AGILE platform trial, a phase I/II adaptive design for novel COVID-19 treatments. Results We present discussion of the practical delivery of AGILE, covering what information was found to support principled decision making by the Safety Review Committee, and what could be contained within a statistical analysis plan. We also discuss additional challenges we encountered in the study and discuss more generally what (unplanned) adaptations may be acceptable (or not) in studies using model-based designs. Conclusions This example demonstrates both how to design and deliver an adaptive dose-finding trial in order to support uptake of these methods.

Background: Glioblastoma is a high-grade aggressive neoplasm whose outcomes have not changed in decades. In the current treatment pathway, tumour growth continues and remains untreated for several weeks post-diagnosis. Intensified upfront therapy could target otherwise untreated tumour cells and improve the treatment outcome. POBIG will evaluate the safety and feasibility of single-fraction preoperative radiotherapy for newly diagnosed glioblastoma, assessed by the maximum tolerated dose (MTD) and maximum tolerated irradiation volume (MTIV). Methods: POBIG is an open-label, dual-centre phase I dose and volume escalation trial that has received ethical approval. Patients with a new radiological diagnosis of glioblastoma will be screened for eligibility. This is deemed sufficient due to the high accuracy of imaging and to avoid treatment delay. Eligible patients will receive a single fraction of preoperative radiotherapy ranging from 6 to 14 Gy followed by their standard of care treatment comprising maximal safe resection and postoperative chemoradiotherapy (60 Gy/30 fr) with concurrent and adjuvant temozolomide). Preoperative radiotherapy will be directed to the part of the tumour that is highest risk for remaining as postoperative residual disease (hot spot). Part of the tumour will remain unirradiated (cold spot) and sampled separately for diagnostic purposes. Dose/volume escalation will be guided by a Continual Reassessment Method (CRM) model. Translational opportunities will be afforded through comparison of irradiated and unirradiated primary glioblastoma tissue. Discussion: POBIG will help establish the role of radiotherapy in preoperative modalities for glioblastoma. Trial registration: NCT03582514 (clinicaltrials.gov).

Background: Olipudase alfa is a recombinant human acid sphingomyelinase (ASM) enzyme replacement therapy (ERT) for non-central-nervous-system manifestations of acid sphingomyelinase deficiency (ASMD). We report 2-year cumulative safety and efficacy data after olipudase alfa treatment in 20 children (four adolescents [12–17 year], nine children [6–11 year], and seven infants/early child [1–5 year]) with baseline splenomegaly and growth deficits who completed the 1-year ASCEND-Peds clinical trial (NCT02292654) and who continue to receive olipudase alfa in a long-term study (NCT02004704). Efficacy endpoints include spleen and liver volumes, diffusing capacity of the lung for carbon monoxide (DLCO), high-resolution computed tomography (HRCT) lung imaging, lipid profiles, liver function tests, and height Z-scores. Results: All 20 former ASCEND-Peds patients completed at least 2 years of olipudase alfa treatment. No patient discontinued and no new safety issue arose during the second year of treatment; 99% of adverse events were mild or moderate. During year 2, one patient had two treatment-related serious events of hypersensitivity that resolved. Mean reductions from baseline in spleen and liver volumes were 61% and 49%, respectively (p < 0.0001) and mean percent-predicted-DLCO increased by 46.6% (p < 0.0001) in nine patients who performed the test at baseline. Lipid profiles and elevated liver transaminase levels that improved or normalized by 1 year remained stable. Mean height Z-scores improved in all age groups (mean change from baseline 1.17, P < 0.0001). Conclusion: Olipudase alfa was generally well-tolerated during 2 years of treatment. Improvements in clinically relevant disease endpoints observed during the first year of treatment were maintained or augmented in the second year. Trial registration NCT02004704 registered 26 Nov 2013, . [ABSTRACT FROM AUTHOR]

Objective: We report the long term follow-up, toxicity, and outcomes of patients with localized squamous cell carcinoma of the esophagus(ESCC) who underwent definitive chemo-radiotherapy(dCRT) at our institute. Materials and Methods: Patients diagnosed with carcinoma post cricoid, upper cervical and thoracic oesophagus and treated with dCRT between January 2000 and March 2012 were retrospectively analyzed. Radiotherapy was delivered in two phases to a maximum dose of 63Gy in daily fractions of 1.8Gy using conventional or conformal techniques. OS and PFS were defined from date of registration and were calculated by Kaplan-Meier method with comparisons between different subgroups performed using log-rank test. All data were analysed using SPSS Version 22. Results: Three hundred and fourteen patients with ESCC treated with dCRT were included in this analysis. Median age at presentation was 56 years and median KPS at presentation was 70. Two-third of patients were treated with conformal technique. Median dose of radiation delivered was 60Gy(range 30.6Gy–70Gy). Neoadjuvant chemotherapy was administered in about 35% patients and 57% patients received concurrent chemotherapy. About 10% patients required hospitalization during treatment due to complications and 7 patients did not complete treatment. Grade 1/2 dermatitis and mucositis was seen in 77% and 71% patients respectively. Complete response at first follow up was observed in 56% of patients. At a median follow up of 56 months, 77 patients were alive with controlled disease. The 1- and 3-yr OS were 80% and 62% respectively. Median PFS was 28 months; 1- and 3-yr PFS were 66% and 46% respectively. A higher RT dose was found to be a significant predictor for OS and PFS on both uni- and multivariate analysis. Conclusion: Our study highlights that the delivery of higher RT doses (≥63Gy) is feasible in this patient group and that a higher RT dose was associated with significantly better PFS and OS. [ABSTRACT FROM AUTHOR]

The selective phosphatidylinositol 3-kinase δ inhibitor zandelisib demonstrated favorable safety and efficacy [objective response rate (ORR) 79%] in patients with B-cell malignancies in a phase 1b study in the US and Switzerland. In this phase 1 dose-escalation study (NCT03985189), 9 Japanese patients with relapsed/refractory indolent non-Hodgkin's lymphoma (R/R iNHL) received zandelisib on a continuous daily schedule (45 or 60 mg) until progressive disease/unacceptable toxicity. No dose-limiting toxicities were observed. The maximum tolerated dose was not reached. At a median follow-up of 17.5 months, Grade ≥ 3 treatment-emergent adverse events that occurred in 2 or more patients were neutrophil count decreased (55.6%; 5/9) and diarrhea (33.3%; 3/9). Immune-related toxicities, including hepatobiliary disorder, aspartate/alanine aminotransferase increased, diarrhea/colitis, organizing pneumonia, stomatitis, and rash, led to zandelisib discontinuation in 4 patients. The investigator-assessed ORR, based on modified Lugano criteria, was 100%, including 2 complete responses (22.2%; in follicular lymphoma patients receiving 60 mg/day). Median duration of response, progression-free survival, and time to response were 7.9, 11.1, and 1.9 months, respectively. Zandelisib demonstrated a manageable safety profile at 60 mg, the recommended phase 2 dose (RP2D) in Japanese patients. The RP2D resulted in favorable pharmacokinetics and anti-tumor efficacy in Japanese patients with R/R iNHL. Trial registration. NCT03985189 (ClinicalTrials.gov). [ABSTRACT FROM AUTHOR]

• We investigated the impact of organ motion on the effectiveness of hypoxia-guided proton therapy in lung cancer patients. • Large motion amplitude, especially together with increased dose escalation, was associated with a reduction of target coverage and dose homogeneity. • TCP benefits from dose escalation outweigh motion-induced TCP losses. • Large NTCP benefits for lungs, heart and oesophagus were found for escalated proton plans, even compared to photon plans. • Respiratory gating in combination with rescanning is the recommended strategy should motion mitigation be necessary. To investigate the impact of organ motion on hypoxia-guided proton therapy treatments for non-small cell lung cancer (NSCLC) patients. Hypoxia PET and 4D imaging data of six NSCLC patients were used to simulate hypoxia-guided proton therapy with different motion mitigation strategies including rescanning, breath-hold, respiratory gating and tumour tracking. Motion-induced dose degradation was estimated for treatment plans with dose painting of hypoxic tumour sub-volumes at escalated dose levels. Tumour control probability (TCP) and dosimetry indices were assessed to weigh the clinical benefit of dose escalation and motion mitigation. In addition, the difference in normal tissue complication probability (NTCP) between escalated proton and photon VMAT treatments has been assessed. Motion-induced dose degradation was found for target coverage (CTV V 95% up to −4%) and quality of the dose-escalation-by-contour (Q RMS up to 6%) as a function of motion amplitude and amount of dose escalation. The TCP benefit coming from dose escalation (+4–13%) outweighs the motion-induced losses (<2%). Significant average NTCP reductions of dose-escalated proton plans were found for lungs (−14%), oesophagus (−10%) and heart (−16%) compared to conventional VMAT plans. The best plan dosimetry was obtained with breath hold and respiratory gating with rescanning. NSCLC affected by hypoxia appears to be a prime target for proton therapy which, by dose-escalation, allows to mitigate hypoxia-induced radio-resistance despite the sensitivity to organ motion. Furthermore, substantial reduction in normal tissue toxicity can be expected compared to conventional VMAT. Accessibility and standardization of hypoxia imaging and clinical trials are necessary to confirm these findings in a clinical setting. [ABSTRACT FROM AUTHOR]

Background: Localized pancreatic adenocarcinoma carries a poor prognosis even after aggressive therapy. Up to 40% of patients may develop locoregional disease as the first site of failure. As such, there may be a role for intensification of local therapy such as radiation therapy. Radiation dose escalation for pancreatic cancer is limited by proximity of the tumor to the duodenum. However, the duodenum is removed during Whipple procedure, allowing the opportunity to dose escalate with intraoperative radiation therapy (IORT). Although prior studies have shown potential benefit of IORT in pancreatic cancer, these studies did not utilize ablative doses (biologically effective dose [BED10] > 100 Gy). Furthermore, the optimal radiation target volume in this setting is unclear. There has been increased interest in a "Triangle Volume" (TV), bordered by the celiac axis, superior mesenteric artery, common hepatic artery, portal vein, and superior mesenteric vein. Dissection of this area, has been advocated for by surgeons from Heidelberg as it contains extra-pancreatic perineural and lymphatic tracts, which may harbor microscopic disease at risk of mediating local failure. Interestingly, a recent analysis from our institution indicated that nearly all local failures occur in the TV. Therefore, the purpose of this protocol is to evaluate the safety of delivering an ablative radiation dose to the TV with IORT following neoadjuvant chemotherapy and stereotactic body radiation therapy (SBRT).Methods: Patients with non-metastatic pancreatic adenocarcinoma centered in the head or neck of the pancreas will be enrolled. Following treatment with multi-agent neoadjuvant chemotherapy, patients will undergo SBRT (40 Gy/5 fractions) followed by IORT (15 Gy/1 fraction) to the TV during the Whipple procedure. The primary objective is acute (< 90 days) toxicity after IORT measured by Clavien-Dindo classification. Secondary objectives include late (> 90 days) toxicity after IORT measured by Clavien-Dindo classification, overall survival, local progression-free survival, distant metastasis-free survival, and progression-free survival.Discussion: If the results show that delivering an ablative radiation dose to the TV with IORT after neoadjuvant chemotherapy and SBRT is safe and feasible, it warrants further investigation in a phase II trial to evaluate efficacy of this approach. Trial Registration This study was registered at ClinicalTrials.gov on 12/2/2021 (NCT05141513). https://clinicaltrials.gov/ct2/show/NCT05141513. [ABSTRACT FROM AUTHOR]

Background and Purpose: Dose escalation for positive node maybe improve the regional control of patients with node-positive cervical cancer, but the optimal dose for nodes of different sizes remains controversial. The purpose of this study was to explore the individualized dose escalation for lymph nodes (LNs) with different sizes in the definitive radiotherapy of cervical cancer.Methods: A total of 1002 cervical cancer patients with the International Federation of Gynecology and Obstetrics (FIGO 2009) stage IB1-IVA, who were treated by definitively radiotherapy between September 2013 and December 2016 were enrolled. All LNs identified by computed tomography/magnetic resonance imaging (CT/MRI) were assigned into three groups according to the short diameters of < 1 cm, 1-2 cm or ≥ 2 cm at pretreatment.Results: In total, 580 patients with 1310 LNs were detected. The nodal control rate in groups of LNs < 1 cm, 1-2 cm and ≥ 2 cm was 99.4%, 96%, and 75.9%, respectively (P = 0.000). Among LNs < 1 cm, the control, overall survival (OS) and progression-free survival (PFS) rates did not significantly differ among three dose-based groups (≤ 50.4 Gy, 50.4-60 Gy, > 60 Gy) (control rate, 99.4% vs. 99.3% vs. 100%, P = 0.647) (5-year OS, 76.2% vs. 79% vs. 81.6%, P = 0.682) (5-year PFS, 74.1% vs. 73.9% vs. 78.9% P = 0.713). Among LNs of 1-2 cm, the control and PFS rates were significantly higher in the group of dose ≥ 55 Gy than the group of dose < 55 Gy (control rate, 98% vs. 93.6%, P = 0.028) (5-year PFS, 69.6% vs. 56.7%, P = 0.025). However, this did not cause a significant difference for 5-year OS rate (72.6% vs. 68.3%, P = 0.5). Among LNs ≥ 2 cm, the control, OS, and PFS rates were higher in the group of dose ≥ 55 Gy than the group of dose < 55 Gy, while no significant difference was found (control rate, 82.1% vs. 63.2%, P = 0.107) (5-year OS, 60.6% vs. 37.5%, P = 0.141) (5-year PFS, 51.5% vs.37.5%, P = 0.232).Conclusions: Radiation dose escalation is not necessary for LNs < 1 cm, and dose escalation of 55 Gy is enough for LNs of 1-2 cm. [ABSTRACT FROM AUTHOR]

Background: Treatment of opiate addiction with opiate substitution treatment (e.g. methadone) is beneficial. However, some individuals desire or would benefit from abstinence but there are limited options to attenuate problems with opiate withdrawal. Preclinical and preliminary clinical evidence suggests that the GABA-B agonist, baclofen, has the desired properties to facilitate opiate detoxification and prevent relapse. This study aims to understand whether there are any safety issues in administering baclofen to opioid-dependent individuals receiving methadone.Methods: Opiate-dependent individuals (DSM-5 severe opioid use disorder) maintained on methadone will be recruited from addiction services in northwest London (NHS and third sector providers). Participants will be medically healthy with no severe chronic obstructive pulmonary disease or type 2 respiratory failure, no current dependence on other substances (excluding nicotine), no current severe DSM-5 psychiatric disorders, and no contraindications for baclofen or 4800 IU vitamin D (placebo). Eligible participants will be randomised in a 3:1 ratio to receive baclofen or placebo in an adaptive, single-blind, ascending dose design. A Bayesian dose-escalation model will inform the baclofen dose (10, 30, 60, or 90 mg) based on the incidence of 'dose-limiting toxicity' (DLT) events and participant-specific methadone dose. A range of respiratory, cardiovascular, and sedative measures including the National Early Warning Score (NEWS2) and Glasgow Coma Scale will determine DLT. On the experimental day, participants will consume their usual daily dose of methadone followed by an acute dose of baclofen or placebo (vitamin D3) ~ 1 h later. Measures including oxygen saturation, transcutaneous CO2, respiratory rate, QTc interval, subjective effects (sedation, drug liking, craving), plasma levels (baclofen, methadone), and adverse events will be obtained using validated questionnaires and examinations periodically for 5 h after dosing.Discussion: Study outcomes will determine what dose of baclofen is safe to prescribe to those receiving methadone, to inform a subsequent proof-of-concept trial of the efficacy baclofen to facilitate opiate detoxification. To proceed, the minimum acceptable dose is 30 mg of baclofen in patients receiving ≤ 60 mg/day methadone based on the clinical experience of baclofen's use in alcoholism and guidelines for the management of opiate dependence.Trial Registration: Clinicaltrials.gov NCT05161351. Registered on 16 December 2021. [ABSTRACT FROM AUTHOR]

Brachytherapy (BT), a type of focal cancer radiation therapy, delivers a highly focused dose of radiation to localized tumors, sparing surrounding normal tissue. Brachytherapy has been used to treat gynecologic malignancies, particularly cervical cancer, for over 100 years. From the first gynecologic brachytherapy treatments in the early 20th century to the modern era, significant transformations have taken place, largely due to advances in technology. The development of high-dose-rate sources, remote afterloaders, new applicators, and three-dimensional image guidance has increased tumor dose and, consequently, local control and survival, reinforcing brachytherapy's role as an integral component of gynecologic cancer treatment. Current research efforts involving biomarker research, integration of new imaging modalities, radiosensitizing therapies are aimed at further personalizing the dose delivered in BT to further improve local control and reduce treatment's related toxicities. [ABSTRACT FROM AUTHOR]

In 1998, an editorial from the International Journal of Radiation Oncology – Biology – Physics (IJROBP) on the occasion of the publication of Phase I by Zelefsky et al. on 3D radiotherapy dose escalation asked the question: "will more prove better?". More than 20 years later, several prospective studies have supported the authors' conclusions, making dose escalation a new standard in prostate cancer. The data from prospective randomized studies were ultimately disappointing in that they failed to show an overall survival benefit from dose escalation. However, there is a clear and consistent benefit in biochemical recurrence-free survival, which must be weighed on an individual patient basis against the potential additional toxicity of dose escalation. Techniques and concepts have become more and more precise, such as intensity modulated irradiation, simultaneous integrated boost, hypofractionated dose-escalation, pelvic irradiation with involved node boost or focal dose-escalation on gross recurrence after prostatectomy. The objective here was to summarize the prospective data on dose escalation in prostate cancer and in particular on recent advances in the field. In 2022, can we finally say that more has proven better? [ABSTRACT FROM AUTHOR]

Simple Summary: Despite advances in treatment, the treatment outcome of pancreatic cancer still remains poor. Local progression can be a significant cause of several morbidities in pancreatic cancer, and dose escalation is needed. Stereotactic body proton beam therapy (SBPT) can give higher dose while minimizing dose at organ at risk with Bragg peak. The purpose of the present study was to investigate the feasibility of SBPT in pancreatic cancer. SBPT, administered in five fractions of a total 50–60 GyRBE, was performed mostly after induction chemotherapy. Grade 3 or higher gastroduodenal toxicities occurred in 6.1% of cases. The 2-year overall survival and local control rates were 67.6% and 73.0%. SBPT showed favourable treatment outcomes and treatment-related toxicities. It could be a promising alternative to radical surgery. Background/Purpose: This study aimed to evaluate the clinical outcomes of stereotactic body proton beam therapy (SBPT) for pancreatic cancer. Methods: This retrospective study included 49 patients who underwent SBPT for pancreatic cancer between 2017 and 2020. Survival outcomes, bowel-related toxicities, and failure patterns were analysed. SBPT was performed after induction chemotherapy in 44 (89.8%) patients. The dose-fractionation scheme included 60 gray (Gy) relative biological effectiveness (RBE) in five fractions (n = 42, 85.7%) and 50 GyRBE in five fractions (n = 7, 14.3%). The median follow-up was 16.3 months (range, 1.8–45.0 months). Results: During follow-up, the best responses were complete response, partial response, and stable disease in four (8.2%), 13 (26.5%), and 31 (63.3%) patients, respectively. The 2-year overall survival, progression-free survival, and local control (LC) rates were 67.6%, 38.0%, and 73.0%, respectively. Grade ≥ 3 gastroduodenal (GD) toxicity occurred in three (6.1%) patients. Among them, one patient underwent endoscopic haemostasis. The other two patients received surgical management. They were followed up without disease progression for >30 months after SBPT. Overall, there was no significant dosimetric difference between the grade ≥ 2 and lower toxicity groups. Conclusions: SBPT provides relatively high LC rates with acceptable toxicities in pancreatic cancer. [ABSTRACT FROM AUTHOR]

Angiogenesis is a hallmark of cancer development. This study sought to determine the recommended dose of aflibercept, a recombinant fusion protein targeting VEGF-A, VEGF-B and placental growth factor (PlGF), combined with docetaxel in Japanese patients with advanced solid malignancies. This phase I study was planned to include 12 patients following a 3 + 3 algorithm to determine the maximum tolerated dose of aflibercept combined with docetaxel in patients with metastatic or unresectable solid tumors (trial registration: NCT00545246). Docetaxel (75 mg/m2 every 3 weeks or 60 mg/m2 after protocol amendment) was combined with escalating doses of aflibercept (2, 4 and 6 mg/kg every 4 weeks). Free and VEGF-bound aflibercept were measured to assess free aflibercept in excess of the VEGF-bound form. At the starting dose of the combination, 3 of 6 patients treated experienced febrile neutropenia. After reducing the docetaxel dose to 60 mg/m2 in step 2 and permitting therapeutic granulocyte colony-stimulating factor (G-CSF) use, 2 of 3 patients in both cohorts experienced febrile neutropenia. Five patients (42%) had a partial response and 4 patients had stable disease (33%). Free aflibercept in excess of the VEGF-bound form was not maintained at this dose level. The dose limiting toxicity (DLT) of aflibercept combined with docetaxel was febrile neutropenia, which occurred in 2 of 3 Japanese patients at the lowest aflibercept dose level (2 mg/kg) combined with docetaxel (60 mg/m2) and therapeutic G-CSF use. A recommended dose for further studies was not determined because of the DLT at the starting dose. [ABSTRACT FROM AUTHOR]

Purpose: Lenvatinib is started at a standard dose, continuing with dose reduction and interruption, balancing between efficacy and adverse events (AEs). Because few drugs are available for thyroid cancer, efforts for continuing treatment with one agent, such as "dose escalation (DE)", are made. The dose is increased, aiming to regain the anti-tumor effect after dose reduction. The effects of lenvatinib DE in differentiated thyroid carcinoma (DTC) patients are reported. Patients and methods: The efficacy of lenvatinib DE in DTC patients using the serum thyroglobulin (Tg) level and management of AEs was investigated. Results: A total of 70 DE episodes in 33 patients were investigated. The median increased dose was 2.0 (1.0–14.0) mg, increased from 8.6 (2–16) mg to 10.1 (6–24) mg. The serum Tg level decreased in 53 DE episodes. Though the serum Tg level in 17 DE episodes was not decreased, the Tg rate of increase was decreased in 7 of these DE episodes using the Tg-doubling rate. Overall, clinical benefit was seen in 60 (86%) DE episodes. AEs that could not be controlled after DEs were seen in only 16% of cases. No intolerable AEs were observed in patients who received more drug holidays at the time of DEs compared to two times before the DEs. Conclusion: DE may become one of the standard treatment strategies after disease progression if AEs are well managed. Drug holidays may be a key for successfully controlling AEs with DE. DE can be useful for controlling progressive disease with increasing Tg levels. [ABSTRACT FROM AUTHOR]

Background: The burden of pneumococcal diseases remains high in Japan. Pn-MAPS24v is a novel MAPS-based vaccine containing complexes of 24 serotype-specific polysaccharides (PS), non-covalently coupled with fusion protein 1 (CP1). This study evaluated the safety and immunogenicity of different dose levels of Pn-MAPS24v, administered in Japanese adults either subcutaneously (SC) or intramuscularly (IM)., Methods: In this phase 1, dose-escalation, observer-blind trial conducted in Japan, 54 pneumococcal vaccine-naïve adults aged 20-49 years (stage 1), and 72 adults aged 65-85 years (stage 2) were sequentially enrolled. In stage 1, participants were randomized 1:1 (SC:IM) to receive a single Pn-MAPS24v dose at one of the dose levels (1 μg, 2 μg, or 5 μg per PS). In stage 2, participants were randomized 3:1 (Pn-MAPS24v:23-valent pneumococcal polysaccharide vaccine [PPSV23]) and 1:1 (SC:IM) to receive a single dose of either Pn-MAPS24v (one of three dose levels), or PPSV23. Solicited adverse events (AEs) were collected through 7 days post-vaccination, and treatment-emergent AEs (TEAEs) up to 1 month post-vaccination. Serotype-specific opsonophagocytic activity titers and immunoglobulin G (IgG) concentrations, as well as anti-CP1 IgG concentrations were measured before and 1 month post-vaccination., Results: No safety or reactogenicity concerns were identified in any age category across groups. No grade 3-4 TEAEs, serious AEs, or deaths were reported. Regardless of the age category, dose level, administration route, or study vaccine, the frequency of reported TEAEs was low and all vaccine-related TEAEs were mild. Pain, tenderness, and fatigue were the most frequently reported solicited AEs. One month post-vaccination, Pn-MAPS24v induced serotype-specific immune responses that were comparable or higher than those elicited by PPSV23. The immune responses were similar after SC and IM administration., Conclusion: Pn-MAPS24v showed an acceptable safety profile and was immunogenic after SC and IM administration, therefore supporting the further development of Pn-MAPS24v in Japan., Clinicaltrials: gov: NCT04265911., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors report that financial support was provided by Astellas Pharma Inc. (for the study) and by GSK (for cost associated with manuscript development). Dorota Borys is a GSK employee and holds financial equities in GSK. Gurunadh R Chichili is an employee of Astellas Pharma Global Development Inc. Jasdeep Nanra was employee of Affinivax, Inc. at the time the study was designed, initiated, and/or conducted and is currently employee of GSK. Masaki Ebara is an employee of Astellas Pharma Inc. Mioko Iwahana is an employee of Astellas Pharma Inc. Miwa Haranaka has nothing to declare. Richard Malley was employee of Affinivax, Inc. at the time the study was designed, initiated, and/or conducted. Richard Malley was Affinivax, Inc. board member at the time the study was designed, initiated, and/or conducted. Richard Malley has issued or pending patents on MAPS technology. Richard Malley declares potential future payments and royalties as equity holder of Affinivax, Inc. and named co-inventor of MAPS technology. Richard Malley is a former employee of GSK and now a consultant of GSK. Richard Malley received consulting fees from GSK as consultant in the area of vaccines and disclosed GSK support for attending meetings and/or travel, and participation to a GSK Advisory board. Ronald Smulders is an employee of Astellas Pharma Global Development Inc. Shite Sebastian was employee of Affinivax, Inc. at the time the study was designed, initiated, and/or conducted and is currently employee of GSK. Shite Sebastian has issued and pending patents on Multivalent Pneumococcal Vaccine. Takashi Nakano declares consulting fees from Astellas Pharma Inc. and support from Daiichi Sankyo, Mitsubishi Tanabe, Biken, Shionogi, Sanofi, Meiji Seika Pharma, and KM Biologics. Yuki Oizumi is an employee of Astellas Pharma Inc. Atsuki Hashimoto is an employee of Astellas Pharma Inc., (Copyright © 2024. Published by Elsevier Ltd.)

Soft tissue sarcomas (STS) are radioresistant with a low α/β, which may have a biologic benefit with hypofractionation. For unresectable STS, the dose escalation required to achieve durable control is often limited by long-term toxicity risk. We sought to compare an isotoxic approach utilizing hypofractionated accelerated radiation dose-painting (HARD) versus standard fractionated radiation therapy (SFT) in patients with unresected STS. We conducted a retrospective analysis of patients with unresected STS who received either HARD (n = 49) or SFT (n = 43) with photon-based therapy between 1990 and 2022. The 2 HARD regimens each use 3 dose levels based on risk of disease burden. The gross disease, intermediate risk, and low-risk clinical target volumes were treated with either 20-22 fractions of 3/2.5/2-2.2 Gy or 28 fractions of 2.5/2.2/1.8 Gy. SFT included patients treated with definitive intent, receiving ≥ 50 Gy in 1.8-2 Gy per fraction. Clinical endpoints included 3-year local control (LC), overall survival (OS), and progression-free survival (PFS), along with treatment-related toxicity. With a median age of 67 and tumor size of 7 cm, most patients were stage IV (37 %), grade 3 (67 %), had no concurrent systemic therapy (70 %), and were lower extremity tumors (24 %). HARD cohort consisted of higher age, stage, recurrent disease, and median BED 4 (p < 0.05), when compared to SFT. With a median follow-up of 35.9 months, HARD demonstrated significant improvement in 3-year LC (96.4 % vs. 48.4 %, p < 0.001), compared to SFT overall, with a median PFS benefit (16 vs. 10 months, p = 0.037) for non-distantly metastatic patients at baseline. On multivariate analysis, HARD was significantly associated with improved LC (HR 0.058, 95 % CI 0.005-0.682, p = 0.024). The HARD regimen found no significant increase in toxicity, with limited acute grade 3 (24 %, all dermatitis) and late grade 3 toxicity (6 %) observed, with no grade 4 or 5 events. HARD regimen significantly improves LC for unresectable STS without a significant increase in toxicity, when compared to a standard fractionated approach, supporting further prospective investigation of this treatment approach., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective . We propose a criterion of biological effectiveness of nonuniform hypoxia-targeted dose distributions in heterogeneous hypoxic tumors based on equivalent uniform aerobic dose (EUAD). We demonstrate the utility of this criterion by applying it to the model problems in radiotherapy for tumors with different levels of oxygen enhancement ratio (OER) and different degrees of dose nonuniformity. Approach . The EUAD is defined as the uniform dose that, under well-oxygenated conditions, produces equal integrated survival of clonogenic cells in radiotherapy for heterogeneous hypoxic tumors with a non-uniform dose distribution. We define the dose nonuniformity effectiveness (DNE) in heterogeneous tumors as the ratio of the EUAD( D N ) for a non-uniform distribution D N with equal integral tumor dose. The DNE concept is illustrated in a radiotherapy model problem for non-small cell lung cancer treated with hypoxia targeted dose escalation. A two-level cell population tumor model was used to consider the hypoxic and oxygenated tumor cells. D U ) for the uniform dose distribution D U with equal integral tumor dose. The DNE concept is illustrated in a radiotherapy model problem for non-small cell lung cancer treated with hypoxia targeted dose escalation. A two-level cell population tumor model was used to consider the hypoxic and oxygenated tumor cells. Results . Theoretical analysis of the DNE shows that the entire region of the OER can be separated in two regions by a threshold OER th increases with reoxygenation rate, relative hypoxic volume and dose escalation factor. The threshold value of OER th where DNE > 1 indicating higher effectiveness of nonuniform dose distributions and (2) OER < OER th where DNE < 1 indicating higher effectiveness of uniform dose distributions. Our simulations show that the value of the threshold OER th in radiotherapy with conventional fractionation is significant in the range of about 1.2-1.6 depending on selected radiotherapy parameters. In general, the OER th increases with reoxygenation rate, relative hypoxic volume and dose escalation factor. The threshold value of OER th is smaller of about 1.1 for hypofractionated radiotherapy. Significance . The analysis of dose distributions using the DNE shows that the uniform dose distributions may improve biological cell killing effect in heterogeneous tumors with intermediate oxygen levels compared to targeted nonuniform dose distribution., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Radiotherapy, including conventionally fractionated external beam radiation therapy, stereotactic radiosurgery, and fractionated stereotactic radiotherapy, is a cornerstone in the interdisciplinary management of meningiomas. Recent advances in radiation oncology and also in other fields, such as neuropathology and imaging, have various implications for meningioma radiotherapy. This review aims to summarize current and anticipated developments, as well as active clinical trials related to the use of radiotherapy for meningiomas. In imaging, positron emission tomography has proven valuable for assessing the spatial extension of meningiomas and may enhance target delineation, treatment response monitoring, and recurrence assessment after radiotherapy. Particle therapy, including protons and carbon ions, as well as stereotactic radiosurgery and radiotherapy, allow for conformal treatments that permit dose escalation in selected patients with high-grade meningiomas. Additionally, emerging integrated molecular and genetic classifications offer superior risk stratification and may refine patient selection for radiotherapy. However, there is a paucity of active meningioma trials directly investigating or refining the use of radiotherapy. In summary, significant advances in functional imaging, molecular and genetic diagnostics, and radiation treatment techniques hold the potential to improve patient outcomes and to avoid over- and undertreatment. Collaborative efforts and further clinical trials are essential to optimize meningioma radiotherapy., Competing Interests: Declaration of competing interest Felix Ehret has received honoraria and travel support from ZAP Surgical Systems, Inc. Sara C. Erridge is a consultant for Servier. Maximilian Niyazi has honoraria from Brainlab und Astra Zeneca. Matthias Preusser has received honoraria for lectures, consultation, or advisory board participation from the following for-profit companies: Bayer, Bristol-Myers Squibb, Novartis, Gerson Lehrman Group, CMC Contrast, GlaxoSmithKline, Mundipharma, Roche, BMJ Journals, MedMedia, Astra Zeneca, AbbVie, Lilly, Medahead, Daiichi Sankyo, Sanofi, Merck Sharp & Dome, Tocagen, Adastra, Gan & Lee Pharmaceuticals, Janssen, Servier, Miltenyi, Böhringer-Ingelheim, Telix, Medscape. Giuseppe Minniti has received honoraria from Brainlab and is a member of the advisory board of Servier. Helen A. Shih is a section editor and writer for UpToDate, a writer for MedLink Neurology, received research support to the institution from AbbVie, is on the advisory board of Advanced Accelerator Applications, and is a consultant for Servier. All other authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

Background: Chronic myeloid leukemia (CML) treatment in low- and middle-income countries faces significant financial and logistical constraints. In scenarios where second-line tyrosine kinase inhibitors (TKIs) are unavailable or unaffordable, dose escalation of imatinib provides an alternative. This study evaluates the efficacy, safety, and progression-free survival (PFS) outcomes of dose escalation of imatinib in CML patients who experienced suboptimal response or progression on standard doses., Methods: A retrospective analysis of 123 CML patients treated at an Indian university teaching hospital from 2013 to 2016 was conducted. Patients who showed progression on a 400 mg dose of imatinib were escalated to 600 mg, and further to 800 mg if required. Demographic data, progression, and toxicity were analyzed., Results: Out of 123 patients, 78 (63.4%) showed a complete hematologic response after dose escalation. The median PFS was 48 months, with a three-year PFS rate of 67%. Notable toxicities included Grade 3/4 neutropenia in 15% and gastrointestinal disturbances in 12%. Comparatively, studies suggest that switching to a second-line TKI in similar settings results in a higher PFS; however, our findings underscore that dose escalation of imatinib remains a viable alternative when financial constraints limit access to second-line therapies., Conclusion: In resource-constrained settings, dose escalation of imatinib can be an effective strategy for managing CML patients who progress on standard doses., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Yadav et al.)

(1) Background: the aims of this study were to determine the total extent of pancreatic cancer’s internal motions, using Calypso® extracranial tracking, and to indicate possible clinical advantages of continuous intrafractional fiducial-based tumor motion tracking during SABR. (2) Methods: thirty-four patients were treated with SABR for LAPC using Calypso® for motion management. Planning MSCTs in FB and DBH, and 4D-CTs were performed. Using data from Calypso® and 4D-CTs, the movements of the lesions in the CC, AP and LR directions, as well as the volumes of the 4D-CT-based ITV and the volumes of the Calypso®-based ITV were compared. (3) Results: significantly larger medians of tumor excursions were found with Calypso® than with 4D-CT: CC: 29 mm (p < 0.001); AP: 14 mm (p < 0.001) and LR: 11 mm (p < 0.039). The median volume of the Calypso®-based ITV was significantly larger than that of the 4D-CT based ITV (p < 0.001). (4) Conclusion: beside known respiratory-induced internal motions, pancreatic cancer seems to have significant additional motions which should be considered during respiratory motion management. Only direct and continuous intrafractional fiducial-based motion tracking seems to provide complete coverage of the target lesion with the prescribed isodose, which could allow for safe tumor dose escalation.

Enzyme replacement therapy (ERT) with recombinant α-galactosidase A (AGAL) can lead to the formation of neutralizing anti-drug antibodies (ADA), which significantly limit treatment efficacy in patients with Fabry disease (FD). The effects of dose escalation on ADA titer and plasma globotriaosylsphingosine (lyso-Gb3) level are unknown. We screened 250 FD patients (200 males, 50 females) under ERT for ADAs and assessed the impact of an approved dose escalation in affected patients, focusing on ADA titers and plasma lyso-Gb3. ADA-positive patients were identified by serum-mediated inhibition assays, followed by titration assays to determine the individual inhibitory capacities of ADAs against agalsidase-alfa and agalsidase-beta. 70 (35%) of the male patients were ADA-positive, with a mean inhibitory capacity of 83.5 ± 113.7mg AGAL. Although patients receiving agalsidase-beta showed higher inhibitory capacities (84.7 ± 34.7mg) than patients under agalsidase-alfa (60.3 ± 126.7mg, p

The Continual Reassessment Method (CRM) was developed for Phase I trials to identify a maximum‐tolerated dose of an agent using a design in which each participant is treated with a single administration of the agent. We propose an extension of the CRM in which participants receive multiple administrations of an agent using a so‐called step‐up dosing procedure in which participants receive one or more administrations of lower doses of the agent before they receive their penultimate dose. We use methods developed for the CRM to model the probability of DLT for each administration, which leads to the use of conditional probability models to model the joint probability of DLT across multiple administrations. We compare our approach to two existing methods that use time‐to‐event modeling methods for modeling the probability of DLT. We demonstrate through simulations that our approach has operating characteristics similar to existing methods, but due to its foundations in the CRM, ours is simpler to implement than existing approaches and is therefore more likely to be adopted in practice. [ABSTRACT FROM AUTHOR]

Context: Previous studies show that dose escalation for gross tumor volume (GTV) improves local control of esophageal cancer (EC). However, optimal boosting remains uncertain. Recently, functional imaging guidance to achieve dose escalation in high-risk areas of tumors has been proposed.Aims: This study evaluated the feasibility of dose escalation in tumor regions with high fluorodeoxyglucose (FDG) uptake using intensity-modulated radiotherapy (IMRT) and intensity-modulated proton therapy (IMPT).Settings and Design: GTVPET was defined as a high FDG uptake region with 50% SUVmax threshold for dose escalation. IMRT and IMPT plans were generated for three boosting modes: plan 50.4 (50.4 Gy in clinical target volume, CTV), plan 63 (50.4 Gy in CTV, 63 Gy in GTV), plan 70 (50.4 Gy in CTV, 63 Gy in GTV, and 70 Gy in GTVPET).Methods and Material: Eleven patients with squamous cell carcinoma were evaluated. Dose parameters for heart, lung, and spinal cord were compared based on the dose-volume histogram (DVH).Statistical Analysis Used: Paired t-test was performed on the doses to organs-at-risk (OARs) among plan 50.4, plan 63, and plan 70 for IMRT and IMPT.Results: Dosimetric parameters for IMRT for heart, lung, and spinal cord increased significantly for plan 63 and some parameters even exceeded dose limits for OARs. Further dose escalation in GTV-PET did not increase dosimetric parameters significantly. Most dosimetric parameters of OARs in IMPT exhibited no statistical change compared with plan 50.4, and doses to OARs were far less than dose constraints.Conclusions: Dose escalation by IMRT may lead to increased risk of radiation-related injury. Further dose escalation in high FDG uptake regions did not increase doses to OARs. This dose escalation is ideal for achieving better outcomes for EC treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: Bromodomain and extraterminal domain (BET) proteins can regulate cancer-related genes to make tumors grow. BMS-986158, an experimental anticancer therapy, blocks BET protein function. We researched BMS-986158′s potential anticancer effects, side effects, what happens to BMS-986158 in the body, and whether treatment causes any changes in gene activity. To determine the proper dose, 5 different doses were tested using 3 schedules (days taking and not taking therapy). Among 83 patients across all dose schedules, BMS-986158 was generally well tolerated. The most common side effects were diarrhea (43% of patients) and lower platelet cell numbers (blood clotting cells; 39%). Schedule A (cycles of 5 days on and 2 days off therapy) provided stable levels of BMS-986158 in the blood and showed some preliminary anticancer effects, with 30% of patients showing a clinical benefit (a period without meaningful tumor growth in 12 patients and tumor shrinkage by at least 30% in 2 patients). This phase 1/2a, open-label study (NCT02419417) evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of BMS-986158, a selective bromodomain and extraterminal domain (BET) inhibitor. Dose escalation was performed with 3 BMS-986158 dosing schedules: A (5 days on, 2 days off; range, 0.75–4.5 mg), B (14 days on, 7 days off; 2.0–3.0 mg), and C (7 days on, 14 days off; 2.0–4.5 mg). Eighty-three patients were enrolled and received ≥1 BMS-986158 dose. Diarrhea (43%) and thrombocytopenia (39%) were the most common treatment-related adverse events (TRAEs). A lower incidence of TRAEs was found with schedules A (72%) and C (72%) vs. B (100%). Stable disease was achieved in 12 (26.1%), 3 (37.5%), and 9 (31.0%) patients on schedules A, B, and C, respectively. Two patients on schedule A with a 4.5-mg starting dose (ovarian cancer, n = 1; nuclear protein in testis [NUT] carcinoma, n = 1) experienced a partial response. BMS-986158 demonstrated rapid-to-moderate absorption (median time to maximum observed plasma concentration, 1–4 h). As expected with an epigenetic modifier, expression changes in select BET-regulated genes occurred with BMS-986158 treatment. Schedule A dosing (5 days on, 2 days off) yielded tolerable safety, preliminary antitumor activity, and a dose-proportional PK profile. [ABSTRACT FROM AUTHOR]

Background: Biologic therapies are often used in patients with ulcerative colitis (UC) who are nonresponsive to conventional treatments. However, nonresponse or loss of response to biologics often occurs, leading to dose escalation, combination therapy, and/or treatment switching. We investigated real-world treatment patterns of biologic therapies among patients with UC in the USA. Methods: This study analyzed data from the IBM® MarketScan® Commercial and Medicare Supplemental Databases (medical/pharmacy claims for >250 million patients in the USA) to identify patients with UC initiating a biologic therapy (adalimumab, infliximab, golimumab, or vedolizumab) with 12 months of follow-up post-initiation. Key measures were patient baseline characteristics, dose escalation (average maintenance dose >20% higher than label), adherence (proportion of days covered), and ulcerative colitis-related healthcare costs in the 12 months following biologic therapy initiation. Results: Of 2,331 patients included in the study (adalimumab [N = 1,291], infliximab [N = 810], golimumab [N = 127], and vedolizumab [N = 103]), 28.1% used concomitant immunosuppressant therapy within 12 months post-initiation. Overall, 23.6% (adalimumab), 34.8% (infliximab), 9.9% (golimumab), and 39.2% (vedolizumab) of patients dose escalated within 12 months. Patients who dose escalated incurred USD 20,106 higher total UC-related healthcare costs over 12 months than those who did not. Adherence (covariate-adjusted proportion of days covered) ranged from 0.63 to 0.73, and 39.3% of patients discontinued within 12 months (median treatment duration = 112 days). Conclusion: Dose escalation was common, and incurred higher costs, in patients with UC initiating biologic therapies. Suboptimal adherence and/or discontinuation within 12 months of initiation occurred frequently, highlighting the challenges in managing these patients. [ABSTRACT FROM AUTHOR]

Purpose: Dose-escalated external beam radiation therapy (EBRT) and EBRT + high-dose-rate brachytherapy (HDR-BT) boost are guideline-recommended treatment options for localized prostate cancer. The purpose of this study was to compare long-term outcome and toxicity of dose-escalated EBRT versus EBRT + HDR-BT boost. Methods: From 2002 to 2019, 744 consecutive patients received either EBRT or EBRT + HDR-BT boost, of whom 516 patients were propensity score matched. Median follow-up was 95.3 months. Cone beam CT image-guided EBRT consisted of 33 fractions of intensity-modulated radiation therapy with simultaneous integrated boost up to 76.23 Gy (DMean). Combined treatment was delivered as 46 Gy (DMean) EBRT, followed by two fractions HDR-BT boost with 9 Gy (D90%). Propensity score matching was applied before analysis of the primary endpoint, estimated 10-year biochemical relapse-free survival (bRFS), and the secondary endpoints metastasis-free survival (MFS) and overall survival (OS). Prognostic parameters were analyzed by Cox proportional hazard modelling. Genitourinary (GU)/gastrointestinal (GI) toxicity evaluation used the Common Toxicity Criteria for Adverse Events (v5.0). Results: The estimated 10-year bRFS was 82.0% vs. 76.4% (p = 0.075) for EBRT alone versus combined treatment, respectively. The estimated 10-year MFS was 82.9% vs. 87.0% (p = 0.195) and the 10-year OS was 65.7% vs. 68.9% (p = 0.303), respectively. Cumulative 5‑year late GU ≥ grade 2 toxicities were seen in 23.6% vs. 19.2% (p = 0.086) and 5‑year late GI ≥ grade 2 toxicities in 11.1% vs. 5.0% of the patients (p = 0.002); cumulative 5‑year late grade 3 GU toxicity occurred in 4.2% vs. 3.6% (p = 0.401) and GI toxicity in 1.0% vs. 0.3% (p = 0.249), respectively. Conclusion: Both treatment groups showed excellent long-term outcomes with low rates of severe toxicity. [ABSTRACT FROM AUTHOR]

Background: We aimed to determine the safety and efficacy of nintedanib, an oral anti-angiogenic tyrosine kinase inhibitor, in combination with pembrolizumab, an anti-PD1 immunotherapy, in patients with advanced solid tumors (PEMBIB trial; NCT02856425). Methods: In this monocentric phase Ib dose escalation cohort, we evaluated escalating doses of nintedanib (Dose level 1 (DL1) = 150 mg bid [bis in die, as twice a day]; DL2 = 200 mg bid, oral delivery) in combination with pembrolizumab (200 mg Q3W, IV). Patients received a 1-week lead-in dose of nintedanib monotherapy prior starting pembrolizumab. The primary objective was to establish the maximum tolerated dose (MTD) of the combination based on dose limiting toxicity (DLT) occurrence during the first 4 weeks. Secondary objectives were to assess the anti-tumor efficacy and to identify the associated immune and angiogenic parameters in order to establish the recommended nintedanib dose for expansion cohorts. Flow cytometry (FC), Immuno-Histo-Chemistry (IHC) and electrochemiluminescence multi-arrays were prospectively performed on baseline & on-treatment tumor and blood samples to identify immune correlates of efficacy. Results: A total of 12/13 patients enrolled were evaluable for DLT (1 patient withdrew consent prior receiving pembrolizumab). Three patients at 200 mg bid experienced a DLT (grade 3 liver enzymes increase). Four patients developed grade 1–2 immune related adverse events (irAE). Eight patients died because of cancer progression. Median follow-up was 23.7 months (95%CI: 5.55–40.5). Three patients developed a partial response (PR) (ORR = 25%) and five patients (42%) had durable clinical benefit (DCB), defined as PR or stable disease (SD) ≥ 6 months. At baseline, patients with DCB had higher plasma levels of Tie2, CXCL10, CCL22 and circulating CD4+ PD1+ OX40+ T cells than patients without DCB. Patients with DCB presented also with more DC-LAMP+ dendritic cells, CD3+ T cells and FOXP3+ Tregs in baseline tumor biopsies. For DCB patients, the nintedanib lead-in monotherapy resulted in higher blood CCL3, Tregs and CCR4+ CXCR3+ CXCR5− memory CD4 T cells. After the first pembrolizumab infusion, patients with DCB showed lower IL-6, IL-8, IL-27 plasma levels. Conclusion: Nintedanib 150 mg bid is the recommended dose for combination with pembrolizumab and is currently investigated in multiple expansion cohorts. Early tumoral and circulating immune factors were associated with cancer outcome under nintedanib & pembrolizumab therapy. Trial registration: ClinicalTrials.gov, NCT02856425. Registered August 4, 2016 — Prospectively registered. [ABSTRACT FROM AUTHOR]

Stereotactic body radiotherapy (SBRT) is a technologically sophisticated form of radiotherapy that holds significant potential to effectively treat high-risk prostate cancer (HRPC). Prostate SBRT has been the subject of intense investigation in the context of low- and intermediate-risk disease, but less so for HRPC. However, emerging data are demonstrating its potential to safely and efficiently delivery curative doses of radiotherapy, both to the prostate and elective lymph nodes. SBRT theoretically hits harder through radiobiological dose escalation facilitated by ultra-hypofractionation (UHRT), faster with only five treatment fractions, and smarter by using targeted, focal dose escalation to maximally ablate the dominant intraprostatic lesion (while maximally protecting normal tissues). To achieve this, advanced imaging modalities like magnetic resonance imaging and prostate specific membrane antigen positron emmission tomography (PSMA-PET) are leveraged in combination with cutting-edge radiotherapy planning and delivery technology. In this focused narrative review, we discuss key evidence and upcoming clinical trials evaluating SBRT for HRPC with a focus on dose escalation, elective nodal irradiation, and focal boost. [ABSTRACT FROM AUTHOR]

Purpose: Report the outcomes of patients with non-small cell lung cancer (NSCLC) and peripheral tumors treated with simultaneous integrated biologically equivalent dose (BED)-escalation (SIBE) lung stereotactic body radiation therapy (SBRT) to achieve dose escalation. Materials/methods: Patients with NSCLC within 5 mm of the chest wall treated with a SIBE approach were eligible. Patients received 60 Gy in 5 fractions, with dose decreased to 50 Gy based on proximity to the chest wall. Dosimetry, oncologic outcomes, and toxicity were evaluated. Results: Twenty-four patients met inclusion criteria. Median BED to the PTV was 135.4 Gy. Median chest wall V30 was 18.7 cc. The 3-year LC, OS, and PFS of the non-metastatic cohort was 93%, 35%, and 39%, respectively. The crude rate of chest wall toxicity was 12.5%, with no rib fractures. Conclusions: SIBE lung SBRT appears to be well tolerated and achieves favorable local control rates and survival. [ABSTRACT FROM AUTHOR]

The SCOPE 2 trial of definitive chemoradiotherapy in oesophageal cancer investigates the benefits of radiotherapy dose escalation and systemic therapy optimisation. The trial opened in 2016. The landscape of oesophageal cancer treatment over the lifetime of this trial has changed significantly and the protocol has evolved to reflect this. However, with the recent results of the Dutch phase III ART DECO study showing no improvement in local control or overall survival with radiotherapy dose escalation in a similar patient group, we sought to determine if the SCOPE 2 trial is still answering the key unanswered questions for oesophageal radiotherapy. Here we discuss the rationale behind the SCOPE 2 trial, outline the trial schema and review current data on dose escalation and outline recommendations for future areas of research. • Building on SCOPE series of trials, shaping UK oesophageal radiotherapy development. • Radiotherapy dose escalation and systemic therapy personalisation in oesophageal cancer. • Role of PET/CT in treatment response assessment. • Future research strategies for oesophageal cancer. [ABSTRACT FROM AUTHOR]

Background and purpose: Radiation dose escalation to improve poor outcomes with chemoradiation in locally advanced esophageal carcinoma is limited in part by increased toxicity. This Phase I study investigates the use of IMRT to improve tolerability of dose escalation. Materials and methods: A single-institution, prospective study was conducted between 2007 and 2013 for individuals with inoperable esophageal carcinoma. Gross disease received 60 Gy in 30 fractions and at-risk sites received 54 Gy with simultaneous integrated boost. Concurrent chemotherapy primarily consisted of cisplatin/5-FU. The primary objective was to assess feasibility (

This study compares conventional and robotic intensity modulated radiation therapy (IMRT) plans for prostate boost treatments and provides clinical insight into the strengths and weaknesses of each. The potential for dose escalation with robotic IMRT is further investigated using the "critical volume tolerance" method proposed by Roach et al. Three clinically acceptable treatment plans were generated for 10 prostate boost patients: (1) a robotic IMRT plan using fixed cones, (2) a robotic IMRT plan using the Iris variable aperture collimator, and (3) a conventional linac based IMRT (c-IMRT) plan. Target coverage, critical structure doses, homogeneity, conformity, dose fall-off, and treatment time, were compared across plans. The average bladder and rectum V75 was 17.1%, 20.0%, and 21.4%, and 8.5%, 11.9%, and 14.1% for the Iris, fixed, and c-IMRT plans, respectively. On average the conformity index (nCI) was 1.20, 1.30, and 1.46 for the Iris, fixed, and c-IMRT plans. Differences between the Iris and the c-IMRT plans were statistically significant for the bladder V75 (P= .016), rectum V75 (P= .0013), and average nCI (P =.002). Dose to normal tissue in terms of R50 was 4.30, 5.87, and 8.37 for the Iris, fixed and c-IMRT plans, respectively, with statistically significant differences between the Iris and c-IMRT (P = .0013) and the fixed and c-IMRT (P = .001) plans. In general, the robotic IMRT plans generated using the Iris were significantly better compared to c-IMRT plans, and showed average dose gains of up to 34% for a critical rectal volume of 5%.

Stereotactic body radiotherapy (SBRT) is a technologically sophisticated form of radiotherapy that holds significant potential to effectively treat high-risk prostate cancer (HRPC). Prostate SBRT has been the subject of intense investigation in the context of low- and intermediate-risk disease, but less so for HRPC. However, emerging data are demonstrating its potential to safely and efficiently delivery curative doses of radiotherapy, both to the prostate and elective lymph nodes. SBRT theoretically hits harder through radiobiological dose escalation facilitated by ultra-hypofractionation (UHRT), faster with only five treatment fractions, and smarter by using targeted, focal dose escalation to maximally ablate the dominant intraprostatic lesion (while maximally protecting normal tissues). To achieve this, advanced imaging modalities like magnetic resonance imaging and prostate specific membrane antigen positron emmission tomography (PSMA-PET) are leveraged in combination with cutting-edge radiotherapy planning and delivery technology. In this focused narrative review, we discuss key evidence and upcoming clinical trials evaluating SBRT for HRPC with a focus on dose escalation, elective nodal irradiation, and focal boost.

Objective: To assess the feasibility of dose escalation guided by 18F-deoxyglucose positron emission tomography/computer tomography (18F-FDG PET/CT) for esophageal cancer (EC). Methods and materials: Ten random patients treated with definitive chemoradiotherapy and pre-therapeutic 18F-FDG PET/CT were included in this study. Retrospectively, a threshold of 50% of SUVmax was used to define the high FDG uptake region of the GTV (GTVPET). Three intensity-modulated radiation therapy (IMRT) plans were generated, delivering three dose levels to three different planning target volumes (PTVs). 50.4 ​Gy delivered to PTV50.4 was defined on computed tomography (CT) as Plan50.4, 63 ​Gy was delivered to PTV63 was defined as GTV plus a uniform margin of 0.5 ​cm as Plan63, and 70 ​Gy delivered to PTV70 was defined as GTVPET plus a 0.5 ​cm margin as Plan70. A dosimetric comparison was performed based on normal tissue complication probability (NTCP) for the lung and heart. Results: Clinically acceptable dose escalation failed for 2 of 10 patients in Plan63 due to heart dose constraints. One patient failed heart dose constraint for Plan70. Two patients failed spinal cord constraint for Plan63. Three patients failed lung dose constraints for both Plan63 and Plan70, two of which were even not suitable for Plan50.4 for the same reason.NTCP modeling for lung showed increased risk for Plan63 and Plan70 compared to Plan50.4. The difference between Plan63 and Plan70 was insignificant. NTCP modeling for heart showed an increased risk from 6.38% of Plan50.4 to 8.88% of Plan70 (P ​= ​0.009) or 9.79% of Plan63 (P ​= ​0.007). The risk of heart mortality was significantly higher for Plan63 than Plan70 (P ​= ​0.047). Conclusions: Selective boosting of sub-volumes based on 18F-FDG PET/CT is feasible way with a modest increase in the risk of cardiac and lung toxicities.

The multi-centre two-stage SCALOP-2 trial (ISRCTN50083238) assessed whether dose escalation of consolidative chemoradiotherapy (CRT) or concurrent sensitization using the protease inhibitor nelfinavir improve outcomes in locally advanced pancreatic cancer (LAPC) following four cycles of gemcitabine/nab-paclitaxel. In stage 1, the maximum tolerated dose (MTD) of nelfinavir concurrent with standard-dose CRT (50.4 Gy in 28 fractions) was identified from a cohort of 27 patients. In stage 2, 159 patients were enrolled in an open-label randomized controlled comparison of standard versus high dose (60 Gy in 30 fractions) CRT, with or without nelfinavir at MTD. Primary outcomes following dose escalation and nelfinavir use were respectively overall survival (OS) and progression free survival (PFS). Secondary endpoints included health-related quality of life (HRQoL). High dose CRT did not improve OS (16.9 (60 % confidence interval, CI 16.2–17.7) vs. 15.6 (60 %CI 14.3–18.2) months; adjusted hazard ratio, HR 1.13 (60 %CI 0.91–1.40; p = 0.68)). Similarly, median PFS was not improved by nelfinavir (10.0 (60 %CI 9.9–10.2) vs. 11.1 (60 %CI 10.3–12.8) months; adjusted HR 1.71 (60 %CI 1.38–2.12; p = 0.98)). Local progression at 12 months was numerically lower with high-dose CRT than with standard dose CRT (n = 11/46 (23.9 %) vs. n = 15/45 (33.3 %)). Neither nelfinavir nor radiotherapy dose escalation impacted on treatment compliance or grade 3/4 adverse event rate. There were no sustained differences in HRQoL scores between treatment groups over 28 weeks post-treatment. Dose-escalated CRT may improve local tumour control and is well tolerated when used as consolidative treatment in LAPC but does not impact OS. Nelfinavir use does not improve PFS. • Nelfinavir and high-dose chemoradiotherapy (CRT) are well tolerated. • No improvement in overall survival is seen with high versus standard dose CRT. • Nelfinavir does not improve outcomes when used concurrent with CRT. • CRT dose escalation may improve local tumour control. • Health-related quality of life is not impacted by CRT dose escalation or nelfinavir. [ABSTRACT FROM AUTHOR]

Evaluation of the relative performance of different dose-finding designs is typically carried out using extensive simulations averaged over broad ranges of potential scenarios. Unfortunately, such evaluation lacks rigor, is not reliable and, in general, is not reproducible. Under identical experimental conditions one study will show that method B improves upon method A, another study will show the converse. This does not allow the user to proceed with the conviction of having made the more suitable choice. The source of the problem stems from our failure to address the fact that, in practice, we are dealing with heterogeneous populations. Leaning upon the thinking, and tools, of causal inference, we show here how to address the issue of heterogeneity and how to obtain rigorous, reliable and reproducible evaluation. Causal evaluation allows us to eliminate biases and unneeded sources of variability. The focus changes so that we look at the individual studies themselves rather than average behavior over many studies, i.e., we make comparisons before we average rather than the usual practice which is the other way around. Theoretical justifications and numerical illustrations are provided. • A new paradigm, and algorithm, are proposed that enable an unbiased comparison of dose-escalation designs in early phase trials. • Analogous to matched/paired studies, the designs are compared on the same subjects. Evaluations are fully reproducible. • The greater sensitivity of the approach allows investigators to observe clear differences between designs that have been previously considered to be effectively equivalent. • Earlier conclusions from previous approaches are seen to not always hold. [ABSTRACT FROM AUTHOR]

• This multicenter phase 3 trial compared adaptive & FDG-PET-guided radiotherapy (rRT) to conventional radiotherapy in LAHNSCC. • FDG-PET-guided dose escalation did not significantly improve locoregional control, progression-free or overall survival. • Dose escalation was successfully delivered with comparable toxicity using adaptive and dose redistribution strategies. • rRT improved locoregional control in patients with oropharynx (HPV+/-) and N0-1 disease, which warrants further evaluation. This multicenter randomized phase III trial evaluated whether locoregional control of patients with LAHNSCC could be improved by fluorodeoxyglucose-positron emission tomography (FDG-PET)-guided dose-escalation while minimizing the risk of increasing toxicity using a dose-redistribution and scheduled adaptation strategy. Patients with T3-4-N0-3-M0 LAHNSCC were randomly assigned (1:1) to either receive a dose distribution ranging from 64-84 Gy/35 fractions with adaptation at the 10th fraction (rRT) or conventional 70 Gy/35 fractions (cRT). Both arms received concurrent three-cycle 100 mg/m2 cisplatin. Primary endpoints were 2-year locoregional control (LRC) and toxicity. Primary analysis was based on the intention-to-treat principle. Due to slow accrual, the study was prematurely closed (at 84 %) after randomizing 221 eligible patients between 2012 and 2019 to receive rRT (N = 109) or cRT (N = 112). The 2-year LRC estimate difference of 81 % (95 %CI 74–89 %) vs. 74 % (66–83 %) in the rRT and cRT arm, respectively, was not found statistically significant (HR 0.75, 95 %CI 0.43–1.31, P=.31). Toxicity prevalence and incidence rates were similar between trial arms, with exception for a significant increased grade ≥ 3 pharyngolaryngeal stenoses incidence rate in the rRT arm (0 versus 4 %, P=.05). In post-hoc subgroup analyses, rRT improved LRC for patients with N0-1 disease (HR 0.21, 95 %CI 0.05–0.93) and oropharyngeal cancer (0.31, 0.10–0.95), regardless of HPV. Adaptive and dose redistributed radiotherapy enabled dose-escalation with similar toxicity rates compared to conventional radiotherapy. While FDG-PET-guided dose-escalation did overall not lead to significant tumor control or survival improvements, post-hoc results showed improved locoregional control for patients with N0-1 disease or oropharyngeal cancer treated with rRT. [ABSTRACT FROM AUTHOR]

• Subvolumes for dose escalation of head and neck cancer (HNC) were defined on interim FDG-PET. • Interim PET subvolumes were assumed to define biological target volumes (BTV). • In silico interim dose escalation with proton therapy to BTV in HNC was feasible. • Dose escalation did not severely increase organs at risk doses in cases with favorable BTV location. Image-driven dose escalation to tumor subvolumes has been proposed to improve treatment outcome in head and neck cancer (HNC). We used 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) acquired at baseline and into treatment (interim) to identify biologic target volumes (BTVs). We assessed the feasibility of interim dose escalation to the BTV with proton therapy by simulating the effects to organs at risk (OARs). We used the semiautomated just-enough-interaction (JEI) method to identify BTVs in 18F-FDG-PET images from nine HNC patients. Between baseline and interim FDG-PET, patients received photon radiotherapy. BTV was identified assuming that high standardized uptake value (SUV) at interim reflected tumor radioresistance. Using Eclipse (Varian Medical Systems), we simulated a 10% (6.8 Gy(RBE 1.1)) and 20% (13.6 Gy(RBE 1.1)) dose escalation to the BTV with protons and compared results with proton plans without dose escalation. At interim 18F-FDG-PET, radiotherapy resulted in reduced SUV compared to baseline. However, spatial overlap between high-SUV regions at baseline and interim allowed for BTV identification. Proton therapy planning demonstrated that dose escalation to the BTV was feasible, and except for some 20% dose escalation plans, OAR doses did not significantly increase. Our in silico analysis demonstrated the potential for interim 18F-FDG-PET response-adaptive dose escalation to the BTV with proton therapy. This approach may give more efficient treatment to HNC with radioresistant tumor subvolumes without increasing normal tissue toxicity. Studies in larger cohorts are required to determine the full potential for interim 18F-FDG-PET-guided dose escalation of proton therapy in HNC. [ABSTRACT FROM AUTHOR]

• This study presents results of a randomized phase II trial on hypoxia dose escalation in head and neck cancer (HNC) • Tumor hypoxia assessed with dynamic [18F]FMISO PET/CT is a negative prognostic factor in HNC treated with IMRT. • Hypoxia dose escalation by dose painting radiotherapy is feasible und does not lead to unacceptable toxicity. • Hypoxia dose escalation leads to a statistically non-significant improvement in local control of 25% Tumor hypoxia is a major cause of resistance to radiochemotherapy in locally advanced head-and-neck cancer (LASCCHN). We present results of a randomized phase II trial on hypoxia dose escalation (DE) in LASCCHN based on dynamic [18F]FMISO (dynFMISO) positron emission tomography (PET). The purpose was to confirm the prognostic value of hypoxia PET and assess feasibility, toxicity and efficacy of hypoxia-DE. Patients with LASCCHN underwent baseline dynFMISO PET/CT. Hypoxic volumes (HV) were derived from dynFMISO data. Patients with hypoxic tumors (HV > 0) were randomized into standard radiotherapy (ST: 70Gy/35fx) or dose escalation (DE: 77Gy/35fx) to the HV. Patients with non-hypoxic tumors were treated with ST. After a minimum follow-up of 2 years feasibility, acute/late toxicity and local control (LC) were analyzed. The study was closed prematurely due to slow accrual. Between 2009 and 2017, 53 patients were enrolled, 39 (74%) had hypoxic tumors and were randomized into ST or DE. For non-hypoxic patients, 100% 5-year LC was observed compared to 74% in patients with hypoxic tumors (p = 0.039). The difference in 5-year LC between DE (16/19) and ST (10/17) was 25%, p = 0.150. No relevant differences related to acute and late toxicities between the groups were observed. This study confirmed the prognostic value of hypoxia PET in LASCCHN for LC. Outcome after hypoxia DE appears promising and may support the concept of DE. Slow accrual and premature closure may partly be due to a high complexity of the study setup which needs to be considered for future multicenter trials. [ABSTRACT FROM AUTHOR]

Introduction: The number of beams used in a Radiotherapy (RT) plan effects the overall quality of the plan and hence the treatment. The inclusion of radiobiological concepts in finding the optimum number of beams for a particular planning technique has the potential to provide a step ahead of the routine clinical practice where clinical decisions are more dependent on the physical dose parameters. Aim: To optimise the number of beams for Intensity Modulated Radiotherapy (IMRT) plan based on Tumour Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) biological parameters. Materials and Methods: This retrospective study was done on 30 patients with pituitary macro-adenoma who underwent radiotherapy with a prescribed dose of 50.4 Gy in 28 fractions in Delhi State Cancer Institutes, Delhi, India from December 2012 to August 2018. The study data was collected and analysed between June 2018 and April 2020. These patients were treated with step and shoot IMRT technique on ONCORTM Expression linear accelerator (Siemens Healthineers, USA). But, the number of beams used to deliver IMRT plans were different as decided by the medical physicist and hence planner dependent rather than the disease. Being a centrally located disease, a symmetric beam arrangement was adopted for IMRT planning. For dosimetric comparison, three IMRT plans with five, seven, and nine equispaced beams were generated in Monaco treatment planning system for each patient and thus, a total of 90 IMRT plans were created and evaluated. For fair comparison, same IMRT planning parameters were utilized in all three plans of each patient. Monte Carlo (MC) dose calculation algorithm was used for all the plans. Resulting Cumulative Dose Volume Histograms (CDVHs) were exported to MATLAB, where these cDVHs were processed as per Niemierko's radiobiological model to calculate the values of TCP and NTCP based on the Equivalent Uniform Dose (EUD). After this, the analysis of variance, ANOVA test was conducted over the resulting values of EUD, TCP, and NTCP to assess the difference of quality among plans having different beam arrangements at 0.05 level of significance. Results: The mean tumour control probability (TCP) for IMRT plans with seven and nine beams were found to be 89.0±0.8% and 89.1±0.9% respectively for planning target volume (PTV). These values were not significantly different from each other. However, the mean TCP value for IMRT plans with five beams was found to be 88.4±1.1% for PTV. Further, this TCP value was proved to be significantly lower as compared to IMRT plans with seven and nine beams with a p-value of 0.008 and 0.004 respectively. On the other hand, the mean Normal Tissue Complication Probability (NTCP) was assessed to be less than 1% for all critical organs irrespective of the beam arrangement, indicating almost no probability of radiation induced toxicity in any of the organ. Conclusion: This study concludes that the plan efficiency can be improved by using optimum number of beams for IMRT planning of pituitary adenoma. [ABSTRACT FROM AUTHOR]