Radiotherapy for brain metastasis and long-term survival

Area of Science:

• Oncology
• Radiation Oncology
• Medical Informatics

Background:

• Brain metastases (BM) present a significant challenge in cancer care.
• The long-term survival benefits of radiotherapy (RT) for BM are not fully understood.
• Understanding RT modality effectiveness is crucial for treatment optimization.

Purpose of the Study:

• To evaluate the survival outcomes of patients with brain metastases (BM) treated with different radiotherapy (RT) modalities.
• To compare the effectiveness of whole-brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS) in a real-world setting.
• To identify patient subgroups that benefit most from RT.

Main Methods:

• Utilized a Korean national health insurance claims database (2002-2017) to identify 135,740 patients with newly diagnosed BM.
• Applied propensity score matching (PSM) to compare survival between patients who received RT and those who did not.
• Analyzed survival data for different RT modalities, including WBRT and SRS, and stratified by primary cancer type (e.g., lung cancer).

Main Results:

• After PSM, 37,046 patients received RT, showing significantly better 1-year overall survival (42.4% vs. 35.3%, P<0.001) compared to non-RT patients.
• No significant difference in survival was observed at 2.6 years, with non-RT patients having better 5-year survival.
• For lung cancer BM, RT improved 1-year survival (57.3% vs. 32.8%, P<0.001) with a median survival increase of 3.7 months.
• Stereotactic radiosurgery (SRS) demonstrated a significantly better 1-year overall survival rate than whole-brain radiotherapy (WBRT) (46.4% vs. 38.8%, P<0.001).

Conclusions:

• Radiotherapy (RT) significantly improves short-term survival for Korean patients with brain metastases (BM), especially those with primary lung cancer.
• Stereotactic radiosurgery (SRS) appears to be a more effective modality than whole-brain radiotherapy (WBRT) for improving survival in this patient population.
• While RT offers short-term benefits, long-term survival advantages require further investigation, particularly concerning the balance between treatment benefits and potential long-term adverse effects.