Primary or salvage stereotactic radiosurgery for brain metastatic small cell lung cancer

PurposeWe evaluated the outcomes after stereotactic radiosurgery (SRS) for patients who developed new or progressive brain disease regardless of whether they had no prior radiation, PCI, or WBRT.MethodsWe retrospectively identified 90 SCLC patients who had SRS between 1991 and 2018. Thirty-one patients had no evidence of brain disease at the time of initial diagnosis but received prophylactic cranial irradiation. Twenty-six without initial brain disease underwent delayed SRS after brain disease was identified. Seventeen patients with synchronous systemic and brain disease underwent WBRT at the time of diagnosis. Fifteen patients had brain disease detected at the time of initial diagnosis and had initial SRS.ResultsWe found no difference in overall survival between patients who received initial PCI or WBRT compared to patients treated with SRS alone at the time when brain metastases were identified. PCI was not associated with a longer duration between initial diagnosis and the development of brain metastasis. Local tumor control was achieved in 49 out of 58 patients who had follow up MRI available for review (84.5%). Actuarial local tumor control at 3, 6, and 12months was calculated as 92%, 85%, and 80%, respectively. Radiation therapy (PCI or WBRT) before SRS was not associated with better or worse local tumor control.ConclusionIn this experience neither prior PCI nor WBRT improved survival or local tumor control in SCLC patients who underwent SRS for new or recurrent brain disease.