Normal Brain-Sparing Radiotherapy versus Whole Brain Radiotherapy for Multiple Brain Metastasis from Non-Small Cell Lung Cancer.

Purpose: The efficacy and lower neurotoxicity of normal brain-sparing radiotherapy (NBS-RT) with systemic therapy in treating multiple brain metastases from non-small cell lung cancer (NSCLC) is underexplored. This study compares whole brain radiotherapy (WBRT) and NBS-RT for multiple brain metastases in NSCLC, focusing on treatment outcomes and leukoencephalopathy.

Materials and methods: This retrospective study included 503 patients with NSCLC with multiple brain metastases at a single center, treated with either WBRT or NBS-RT. Post-RT treatments included chemotherapy, targeted therapy, or immunotherapy. Main outcomes measured were intracranial control, overall survival (OS), and leukoencephalopathy incidence.

Results: In this study, 441 patients received WBRT and 62 received NBS-RT, with median ages of 62 and 61 years, respectively. A significant portion of both groups, 77.3% in WBRT and 80.6% in NBS-RT, received post-RT systemic therapy. The median number of brain metastases was 10 for WBRT and 12 for NBS-RT, with median maximal diameters of 11.7 mm in WBRT and 14.4 mm in NBS-RT. After a median follow-up of 10.9 months for WBRT and 11.8 months for NBS-RT, there were no significant differences in intracranial progression (p=0.516) or OS (p=0.492) between the groups. However, WBRT patients had a higher incidence of leukoencephalopathy than NBS-RT patients (p=0.013).

Conclusion: NBS-RT combined with systemic therapy was as effective in treating multiple brain metastases as WBRT and was less toxic. NBS-RT-based strategies deserve further investigation in a prospective setting.