Association of Bevacizumab Added to Chemotherapy and Whole-Brain Radiotherapy with Peritumoral Edema and Prognosis in Patients with Brain Metastases from Non-Squamous Non-Small Cell Lung Cancer

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Background Peritumoral edema is a common complication of brain metastases from non-squamous non-small cell lung cancer (NSCLC) and may aggravate neurological symptoms and compromise patients’ tolerance to whole-brain radiotherapy. This study quantitatively assessed serum vascular endothelial growth factor (VEGF) levels and magnetic resonance imaging (MRI)–derived edema parameters to evaluate the association of adding bevacizumab to chemotherapy and whole-brain radiotherapy with peritumoral edema, intracranial tumor response, and survival outcomes in patients with brain metastases from NSCLC. Methods Seventy-six patients with non-squamous NSCLC and brain metastases were retrospectively analyzed. Both groups received pemetrexed plus carboplatin chemotherapy and whole-brain radiotherapy. The research group (RG; n=38) additionally received bevacizumab, whereas the control group (CG; n=38) did not. Serum VEGF concentrations and quantitative MRI volumetry — peritumoral edema volume (V_edema), brain tumor volume (V_tumor), and edema index (EI = [V_edema + V_tumor]/V_tumor) — were used as primary analytical readouts. The intracranial objective response rate (ORR) and disease control rate (DCR) were assessed, while safety profiles and survival outcomes, including overall survival (OS) and progression-free survival (PFS), were also recorded. Results After completion of whole-brain radiotherapy, the RG showed significant reductions in V_edema, V_tumor, EI, and serum VEGF levels ( P <0.05) relative to the CG ( P <0.05). ORR and DCR in the RG were markedly higher than the CG values (76.32% vs. 52.63%, P =0.0310; 92.11% vs. 71.05%, P =0.0179), while RG median OS and PFS were substantially prolonged relative to the CG rates ( P <0.05). Multivariable Cox modeling identified older age ( P =0.0311), clinical stage IV B ( P =0.0037), larger maximum brain metastasis volume ( P =0.0400), and absence of bevacizumab ( P =0.0001) as independent risk factors. Conclusion The addition of bevacizumab to chemotherapy and whole-brain radiotherapy was associated with reduced peritumoral edema and intracranial tumor burden, improved intracranial disease control, and longer survival in patients with brain metastases from non-squamous NSCLC, without an observed increase in the overall incidence of adverse events. However, the retrospective single-center design, small sample size, and potential treatment-selection bias limit causal interpretation and the generalizability of these findings. Prospective multicenter studies are warranted to validate these results.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.