RMTD-06 PROPOSAL TO DESIGN A PHASE 2 RANDOMIZED CONTROLLED TRIAL COMPARING LASER INTERSTITIAL THERMAL THERAPY (LITT) AND BEVACIZUMAB FOR THE TREATMENT OF RADIATION NECROSIS IN PATIENTS WITH BRAIN TUMORS

Abstract Cerebral radiation necrosis is a serious complication of radiotherapy for brain tumors, leading to progressive neurological deterioration. Bevacizumab and laser interstitial thermal therapy (LITT) are two treatment options with demonstrated efficacy, but no prospective studies have directly compared their relative effectiveness and safety. We propose a multicenter, phase 2 randomized controlled trial to compare the efficacy and safety of LITT versus bevacizumab in patients with radiation necrosis following cranial irradiation for primary (grades 1, 2 and 3) or metastatic brain tumors. Radiation necrosis will be diagnosed using a combination of clinical, imaging (advanced magnetic resonance imaging (MRI) or positron emission tomography) and, when necessary, histopathologic criteria to distinguish it from tumor progression. A total of 50 patients (aged 18-90 years) will be enrolled based on feasibility considerations, with randomization to LITT or bevacizumab. Stratification by tumor type (primary vs. metastatic) and prior treatments will be incorporated to minimize confounding factors. The primary endpoint is the change in edema volume on MRI from baseline to 3 months. Secondary endpoints include imaging response at 12 months, reduction in dexamethasone dosing, neurological symptom improvement, overall survival, and quality of life measures. Safety will be evaluated using National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), with specific monitoring for treatment-related risks such as intracranial hemorrhage, hypertension or thromboembolism. This trial will provide critical prospective data to inform the optimal treatment strategy for cerebral radiation necrosis, guiding future clinical decision-making.