ROAR-A: re-optimization based Online Adaptive Radiotherapy of anal cancer, a prospective phase II trial protocol.

BACKGROUND: Chemo-radiotherapy with curative intent for anal cancer has high complete remission rates, but acute treatment-related gastrointestinal (GI) toxicity is significant. Toxicity occurs due to irradiation of surrounding normal tissue. Current radiotherapy requires the addition of large planning margins to the radiation field to ensure target coverage regardless of the considerable organ motion in the pelvic region. This increases the irradiated volume and radiation dose to the surrounding normal tissue and thereby toxicity. Online adaptive radiotherapy uses artificial intelligence to adjust the treatment to the anatomy of the day. This allows for the reduction of planning margins, minimizing the irradiated volume and thereby radiation to the surrounding normal tissue.This study examines if cone beam computed tomography (CBCT)-guided oART with daily automated treatment re-planning can reduce acute gastrointestinal toxicity in patients with anal cancer. METHODS/DESIGN: The study is a prospective, single-arm, phase II trial conducted at Copenhagen University Hospital, Herlev and Gentofte, Denmark. 205 patients with local only or locally advanced anal cancer, referred for radiotherapy with or without chemotherapy with curative intent, are planned for inclusion. Toxicity and quality of life are reported with Common Terminology Criteria of Adverse Events and patient-reported outcome questionnaires, before, during, and after treatment. The primary endpoint is a reduction in the incidence of acute treatment-related grade ≥ 2 diarrhea from 36 to 25% after daily online adaptive radiotherapy compared to standard radiotherapy. Secondary endpoints include all acute and late toxicity, overall survival, and reduction in treatment interruptions. RESULTS: Accrual began in January 2022 and is expected to finish in January 2026. Primary endpoint results are expected to be available in April 2026. DISCUSSION: This is the first study utilizing online adaptive radiotherapy to treat anal cancer. We hope to determine whether there is a clinical benefit for the patients, with significant reductions in acute GI toxicity without compromising treatment efficacy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05438836. Danish Ethical Committee: H-21028093.

Interim analysis of patient-reported outcome compliance and dosimetry in a phase 3 randomized clinical trial of oesophagus-sparing spinal radiotherapy.

BACKGROUND: The randomized clinical trial ESO-SPARE investigates if oesophagus-sparing radiotherapy (RT) can reduce dysphagia in patients with metastatic spinal cord compression (MSCC). Patient-reported outcome (PRO) is the only follow-up measure. Due to the fragile patient population, low respondent compliance was anticipated. We performed a planned interim analysis of dosimetry and respondent compliance, to ensure that the protocol requirements were met. METHODS: Patients >18 years referred for cervical/thoracic MSCC radiotherapy in 1-10 fractions were included from two centres. Patients were randomized (1:1) to standard RT or oesophagus-sparing RT, where predefined oesophageal dose constraints were prioritized over target coverage. Patients completed a trial diary with daily reports of dysphagia for 5 weeks (PRO-CTC-AE) and weekly quality of life reports for 9 weeks (QLQ-C30, EQ-5D-5L). According to power calculation, 124 patients are needed for primary endpoint analysis. The sample size was inflated to 200 patients to account for the fragile patient population. The co-primary endpoints, peak patient-reported dysphagia, and preserved ability to walk (EQ-5D-5L), are analysed at 5 and 9 weeks, respectively. The interim analysis was conducted 90 days after the inclusion of patient no 100. Respondent compliance was assessed at 5 and 9 weeks. In all RT plans, oesophagus and target doses were evaluated regarding adherence to protocol constraints. RESULTS: From May 2021 to November 2022, 100 patients were included. Fifty-two were randomized to oesophagus-sparing RT. In 23% of these plans, oesophagus constraints were violated. Overall, the dose to both target and oesophagus was significantly lower in the oesophagus-sparing plans. Only 51% and 41% of the patients were evaluable for co-primary endpoint analysis at five and nine weeks, respectively. Mortality and hospitalization rates were significantly larger in patients who completed <4 days PRO questionnaires. CONCLUSION: Compliance was lower than anticipated and interventions to maintain study power are needed.

One-Year Treatment-Related Side Effects and Quality of Life After Chemoradiotherapy in Squamous Cell Carcinoma of the Anus.

PURPOSE: Patient-reported outcome (PRO) and National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) data for patients with squamous cell carcinoma of the anus (SCCA) treated with modern radiation therapy (RT) are lacking. The primary aim of this study was to report bowel and bladder PRO and NCI-CTCAE for patients with SCCA 1 year after RT. METHODS AND MATERIALS: From 2015 to 2020, we included patients in a prospective Danish national study. Data were collected before treatment (PT) and 1 year after treatment (1Y) using NCI-CTCAE version 4.0, as well as European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and CR29. We evaluated the combined PRO scores according to the European Organisation for Research and Treatment of Cancer scoring guidelines, and classified changes according to score difference from PT to 1Y as no change (0-5), minor (5-10), moderate (11-20), and major (>20). Raw scores were reported as frequencies of each of the scores: Not at all, a little, quite a bit, and very much. RESULTS: Of the 270 patients, 81% had complete data sets, including PT and 1Y answers. Functional mean scores were equal to a matched normal population cohort at PT and 1Y. From PT to 1Y, C30 scores were stable despite minor improvements in global health status/quality of life (7.3), emotional functioning (9.3), insomnia (8.0), and appetite loss (7.8). For questionnaire CR29, bowel and bladder symptoms and sore skin improved with minor change (6.2), and buttocks, anal, or rectal pain improved with moderate change (18.3). Flatulence worsened moderately (12.6), and fecal incontinence had minor worsening (7.8). Agreement between PROs and NCI-CTCAE was generally only fair to moderate, especially for quantitative symptoms, such as pain (κ = 0.25). CONCLUSIONS: For patients with SCCA who underwent definitive RT, only a few patients had high scores (indicating quite a bit or very much frequency of bother) regarding bowel and bladder symptoms.

Online adaptive radiotherapy of anal cancer: Normal tissue sparing, target propagation methods, and first clinical experience.

BACKGROUND AND PURPOSE: Online adaptive radiotherapy (oART) potentially spares OARs as PTV margins are reduced. This study evaluates dosimetric benefits, compared to standard non-adaptive radiotherapy (non-ART), target propagation methods, and first clinical treatments of CBCT-guided oART of anal cancer. MATERIALS AND METHODS: Treatment plans with standard non-ART and reduced oART PTV margins were retrospectively generated for 23 consecutive patients with anal cancer. For five patients randomly selected among the 23 patients, weekly CBCT-guided oART sessions were simulated, where the targets were either deformed or rigidly propagated. Preferred target propagation method and dose to OARs were evaluated. Ten consecutive patients with anal cancer were treated with CBCT-guided oART. Target propagation methods and oART procedure time were evaluated. RESULTS: For the retrospective treatment plans, oART resulted in median reductions in bowel bag V45Gy of 11.4 % and bladder V35Gy of 16.1%. Corresponding values for the simulated sessions were 7.5% and 27.1%. In the simulated sessions, 35% of all targets were deformed while 65% were rigidly propagated. Manual editing and rigid propagation were necessary to obtain acceptable target coverage. In the clinical treatments, the primary and some elective targets were rigidly propagated, while other targets were deformed. The median oART procedure time, measured from CBCT acquisition to completion of plan review and QA, was 23 min. CONCLUSIONS: Simulated oART reduced the dose to OARs, indicating potential reduction in toxicity. Rigid propagation of targets was necessary to reduce the need for manual edit. Clinical treatments demonstrated that oART of anal cancer is feasible but time-consuming.

Nonplatinum-based therapy with Paclitaxel and Capecitabine for advanced squamous cell carcinomas of the anal canal: A population-based Danish anal cancer group study.

BACKGROUND: First-line platinum-based therapy for advanced squamous cell carcinomas of the anal canal (SCCA) implies a risk of substantial side effects, and data on second-line treatment options are limited. Paclitaxel and Capecitabine are a well-known regimen with a moderate toxicity profile, but its efficacy has not been evaluated. METHODS: We conducted a retrospective study using Danish Hospital Registers of patients treated with Paclitaxel and Capecitabine for inoperable, recurrent, or advanced metastatic SCCA in Denmark, between January 2000 and July 2018. RESULTS: A total of 52 patients met the eligibility criteria. Median age was 60.7 years (range 42-83). Efficacy was observed, with an overall response rate in patients receiving first-line (N = 28) and second-line (N = 23) Paclitaxel and Capecitabine of 39.3% (2 with complete responses) and 17.4%, respectively. Median progression-free survival (PFS) was 4.5 months (95% CI 3.3-5.9) and 3.8 months (95% CI 2.4-5.5) with OS of 6.7 months (95% CI 5.9-8.5) and 5.9 months (95% CI 3.9-14), respectively. Performance status ≥2 and neutrophil to lymphocyte ratio ≥4 were significantly associated with a short PFS. CONCLUSION: This study recognizes Paclitaxel and Capecitabine as a potential regimen for advanced SCCA, when recommended first-line therapy is not feasible or as a potential second-line treatment after failure of platinum-based chemotherapy.