13. MANAGEMENT OF BRAIN METASTASES FROM SMALL CELL LUNG CANCER USING SRS

The management of brain metastases in patients with SCLC has become controversial in the MRI era. We examine our institutional experience treating patients with SCLC with stereotactic radiosurgery. We hypothesize that an SRS strategy in well-selected patients with close MRI surveillance will result in acceptable tumor control, and without disproportionate future neurological symptoms associated with intracranial disease.

Patients with a diagnosis of high grade neuroendocrine lung cancer who had undergone SRS between 2013 and 2019 were identified and divided into two groups: SRS-primary and SRS-salvage. SRS-primary was defined as patients who, at time of SRS, had not received previous PCI or WBRT. SRS-salvage was defined as patients who had received previous PCI or WBRT. Primary outcome was intracranial progression free survival. Secondary outcomes included overall survival and neurologic symptom free survival (N-SFS), defined as time to development of neurologic symptoms attributed disease.

Twenty patients were identified with median follow-up of 14.1 months. 11 patients were identified as SRS-primary, 9 as SRS-salvage. Among SRS-primary, median PFS and OS were 6.1 months (range 0.9 – 14.5 months) and 15.6 months (4.1–43.5) respectively. N-SFS was 11.2 months (range 3.6–40.0). 3 of 11 patients developed neurological symptoms attributable to disease. 3 underwent salvage SRS and 2 salvage WBRT. None died from intracranial disease. Among SRS-salvage, median PFS following PCI/WBRT was 9.8 months (range 1.8 – 23.6 months) and OS following salvage SRS 5.5 months (range 1.1 – 27.8 months). 3 of 9 patients developed further brain metastases post-SRS. 1 patient died from intracranial disease.

Among well-selected patients followed with MRI surveillance, our data suggest SRS as primary management of brain metastases from SCLC may be reasonable. Symptomatic intracranial disease was uncommon after SRS, and no patients undergoing upfront SRS died from intracranial disease. Prospective data are required to validate these results.