Comparative effectiveness of multi-fraction stereotactic radiosurgery for surgically resected or intact large brain metastases from non-small-cell lung cancer (NSCLC)

Purpose: to investigate clinical outcomes in patients with large brain metastases from non-small-cell lung cancer (NSCLC) who received surgical resection and postoperative stereotactic radiosurgery or SRS alone. Patients and Methods: Two hundred and twenty-two patients with 241 large brain metastases (2–4 cm in size) who received surgery and multi-fraction SRS (mfSRS) to the resection cavity or mfSRS alone were analyzed. For all lesions the delivered dose was 3 x 9 Gy over three consecutive days. Primary endpoint of the study was local control (LC). Secondary endpoints included early improvement of neurological deficits, changes in performance status, treatment-related toxicity, radiation-induced brain necrosis (RN), distant brain failure (DBF), and overall survival (OS). Kaplan-Meier analysis and cumulative incidence function were used for comparing the probability of failure. Results: At a median follow-up of 13 months, median OS times and 1-year survival rates were comparable: 13.5 months and 59% for patients receiving surgery and postoperative mfSRS to the resection cavity and 15.2 months and 68% for those treated with mfSRS alone (p = 0.2). Median DBF did not differ significantly between groups (surgery and mfSRS,12 months; mfSRS,14 months). Eighteen patients receiving surgery and mfSRS and 17 patients treated with mfSRS alone recurred locally (p = 0.2); respective 6-month and 12-month LC rates were 87% and 83% and 96% and 91% (p = 0.15). The 1-year cumulative incidence rates of RN were 15% and 7% after postoperative mfSRS and mfSRS alone (p = 0.03), respectively. Conclusions: In conclusion, mfSRS is an effective treatment for patients with large brain metastases from NSCLC resulting in equivalent LC and lower RN and risk of leptomeningeal spread compared to surgery and mf-SRS to the resection cavity. Surgery is an effective treatment option for patients with large symptomatic brain metastases who require rapid relief of neurological symptoms caused by tumor mass effect.