Outcomes of re-irradiation for brain recurrence after prophylactic or therapeutic whole-brain irradiation for small cell lung Cancer: a retrospective analysis.

Background: Small cell lung cancer (SCLC) can recur in the brain after whole-brain irradiation (WBI). We documented outcomes after treatment of such recurrences and sought predictors of local control and overall survival (OS).

Materials And Methods: Eighty-five patients with SCLC and brain recurrence after prophylactic or therapeutic WBI in 1998-2015 were identified and data were extracted from the medical records. Survival was estimated with the Kaplan-Meier method, and univariate and multivariate Cox proportional hazards modeling was used to identify factors associated with OS or further brain progression.

Results: Brain recurrence was treated by stereotactic radiosurgery (SRS) in 33 patients (39%), repeat WBI in 14 (16%), chemotherapy-only in 16 (19%), and observation in 22 (26%). Median OS time after brain recurrence (OSrec) was 4.3 months for all patients; 6-month OSrec rates were 58% after SRS, 21% after repeat WBI, 50% after chemotherapy-only, and 5% after observation (P < 0.001). Inferior OSrec was associated with poor performance status (ECOG score ≥ 3) and uncontrolled extracranial disease. Superior OSrec was associated with receipt of ≥4 chemotherapy cycles before brain recurrence and receipt of chemotherapy, SRS, or repeat WBI afterward. Receipt of chemotherapy after brain recurrence correlated with brain progression.

Conclusions: Some patients with brain recurrence after WBI for SCLC can survive for extended periods with appropriate intervention, especially those with adequate performance status or controlled extracranial disease.