Clinical and translational radiation oncology · 2026
Safety and early organ preservation outcomes after dose escalation with MR-guided radiotherapy for rectal cancer (preRADAR): A phase I trial.
СтатьяНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Eijkelenkamp H, Verweij M E, Grimbergen G, Tanaka M, Kensen C M, Janssen T, Vijlbrief T, van Grevenstein W M U, Moons L M G, Koopman M, Lacle M M, Braat M N G J A, Maas M, Consten E C J, Pronk A, Smits A B, Heikens J T, Elias S G, Verkooijen H M, Meijer G J, Couwenberg A, Intven M P W
Аннотация
BACKGROUND AND PURPOSE: Organ preservation is a desirable goal for patients with rectal cancer. Magnetic resonance-guided radiotherapy (MRgRT) enables precise dose delivery and online adaptation. This phase I study (preRADAR) evaluated maximum tolerated dose (MTD) of short course radiotherapy (SCRT; 5x5 Gy) with a subsequent boost using MRgRT in intermediate-risk rectal cancer.
MATERIALS AND METHODS: the trial had a 6 + 3 dose-escalation design. Patients staged T3c-d(MRF-)N0M0 or T1-3(MRF-)N1M0 were treated on a 1.5 Tesla MR-linac with short-course radiotherapy (SCRT; 5 × 5 Gy) followed by 2-4 daily 5 Gy GTV boosts according to the dose level. Safety was assessed by incidence of acute and perioperative dose-limiting toxicities (DLTs) within prespecified time windows and stopping boundaries. Secondary endpoints included technical feasibility (boost PTV V95% > 90%) and organ preservation at six months.
RESULTS: Out of 31 patients screened, sixteen were treated across three dose levels. All fractions were delivered as planned and all adaptive boost fractions achieved the predefined feasibility criterion (PTV V95% >90%). No acute DLTs occurred. Three perioperative DLTs were observed, including two anastomotic leaks requiring reoperation. The MTD was not identified; dose level 2 (SCRT + 4 × 5 Gy boosts) was the highest dose level completed within the DLT stopping boundaries, achieving a 26-week organ preservation rate of 56% (5/9).
CONCLUSION: MRgRT-based enables dose escalation following SCRT in intermediate-risk rectal cancer. The highest evaluated dose level, 4 × 5 Gy GTV boosts after SCRT, was considered safe within the predefined DLT boundaries and feasible for further evaluation.
MATERIALS AND METHODS: the trial had a 6 + 3 dose-escalation design. Patients staged T3c-d(MRF-)N0M0 or T1-3(MRF-)N1M0 were treated on a 1.5 Tesla MR-linac with short-course radiotherapy (SCRT; 5 × 5 Gy) followed by 2-4 daily 5 Gy GTV boosts according to the dose level. Safety was assessed by incidence of acute and perioperative dose-limiting toxicities (DLTs) within prespecified time windows and stopping boundaries. Secondary endpoints included technical feasibility (boost PTV V95% > 90%) and organ preservation at six months.
RESULTS: Out of 31 patients screened, sixteen were treated across three dose levels. All fractions were delivered as planned and all adaptive boost fractions achieved the predefined feasibility criterion (PTV V95% >90%). No acute DLTs occurred. Three perioperative DLTs were observed, including two anastomotic leaks requiring reoperation. The MTD was not identified; dose level 2 (SCRT + 4 × 5 Gy boosts) was the highest dose level completed within the DLT stopping boundaries, achieving a 26-week organ preservation rate of 56% (5/9).
CONCLUSION: MRgRT-based enables dose escalation following SCRT in intermediate-risk rectal cancer. The highest evaluated dose level, 4 × 5 Gy GTV boosts after SCRT, was considered safe within the predefined DLT boundaries and feasible for further evaluation.