MRI-Guided Adaptive Radiotherapy for Limited Peritoneal Metastases (MARACAS Trial).

Resumen breve

This prospective phase II study evaluates the efficacy and safety of MRI-guided stereotactic body radiotherapy (MRIgSBRT) in patients with oligometastatic peritoneal carcinomatosis from gastrointestinal or gynecological tumors. Eligible patients with up to 5 MRI-visible peritoneal lesions and PCI ≤20 will be treated with MRIgSBRT using a hybrid MRI-linear accelerator with online adaptive planning and real-time tumor tracking. The primary endpoint is radiologic response rate according to RECIST 1.1 criteria. Secondary endpoints include overall survival, progression-free survival, local control, chemotherapy-free survival, and treatment-related toxicity. The study aims to assess MRIgSBRT as a safe and non-invasive treatment option for selected patients with limited peritoneal metastatic disease.