Application of Bevacizumab Combined With Fractionated Stereotactic Radiotherapy (FSRT-Bev) Versus Hippocampus-Avoidant Whole-Brain Radiotherapy With Simultaneous Integrated Boost (HA-WBRT-SIB) in Patients With Extensive Brain Metastases From Lung Adenocarcinoma: A Phase III Randomized Controlled Trial Evaluating Intracranial Control Efficacy and Neurocognitive Function
This is a phase 3, randomized, controlled clinical trial comparing two brain-directed treatment strategies for adult patients with extensive brain metastases from lung adenocarcinoma. The trial compares fractionated stereotactic radiotherapy combined with bevacizumab (FSRT-Bev) versus hippocampus-avoidant whole-brain radiotherapy with simultaneous integrated boost (HA-WBRT-SIB). The main objectives are to evaluate intracranial tumor control and preservation of neurocognitive function . Patients will be randomly assigned in a 1:1 ratio to receive either FSRT plus bevacizumab or HA-WBRT-SIB. In the experimental group, FSRT is delivered to visible brain tumors over 5 daily treatments (total 30 Gy, 6 Gy per fraction). Bevacizumab is given intravenously every 3 weeks for 4 cycles. In the control group, patients receive hippocampus-avoidant whole-brain radiation (25 Gy) with a simultaneous dose boost to metastatic lesions (40 Gy total) over 10 daily treatments.
• Age ≥18 years
• Pathologically confirmed non-squamous non-small cell lung cancer (adenocarcinoma)
• Extensive brain metastases meeting any of the following:
⁃ 1-2 metastases with at least one ≥3 cm in diameter; or 3-10 metastases with at least one ≥2 cm; or 11-20 metastases
• Stable extracranial disease
• ECOG performance status 0-2
• Adequate bone marrow, hepatic, and renal function
• Written informed consent