Stereotactic Radiation in Patients With Small Cell Lung Cancer and 1-10 Brain Metastases

This research study is studying stereotactic radiation (focused/pinpoint radiation that targets each individual tumor but not the surrounding brain) instead of whole-brain radiation (radiation targeting the entire brain) as a possible treatment for patients with small cell lung cancer and 1-10 brain metastases. The intervention involved in this study is: -Stereotactic (focused, pinpoint) radiation

Inclusion Criteria: * Participants must have a biopsy-proven tumor consistent with small cell lung cancer and intracranial lesions radiographically consistent with or pathologically proven to be brain metastases. Patients who have undergone prior systemic therapy are eligible. Patients who have undergone resection of one or more brain metastases but who have not yet started adjuvant radiotherapy are eligible for the study. * 1-10 definitive intracranial lesions must be present on MRI of the brain. * Age \>=18 years at diagnosis of brain metastases. Exclusion Criteria: * Participants who have undergone prior radiation for brain metastases. * Participants who have received prophylactic cranial radiation for prevention of brain metastases * Participants who cannot receive gadolinium * Participants with stage IV-V chronic kidney disease or end stage renal disease * Participants with widespread, definitive leptomeningeal disease * Participants with a maximum tumor diameter exceeding 5 cm (if not resected) * Participants with \>6 definitive lesions consistent with brain metastases * Participants with inadequate mental capacity to complete quality of life questionnaires