S1827 (MAVERICK) Testing Whether the Use of Brain Scans Alone Instead of Brain Scans Plus Preventive Brain Radiation Affects Lifespan in Patients With Small Cell Lung Cancer

Inclusion Criteria: * Patient must have a histologically confirmed diagnosis of small-cell lung cancer (SCLC) * Patient must have an MRI of the brain performed within 28 days prior to registration documenting no evidence of brain metastases or leptomeningeal disease. Patient also must not have a history of brain metastases or leptomeningeal disease * Immunotherapy concurrent with and/or adjuvant to first-line therapy is allowed at the discretion of the treating physician. Patients with limited-stage (LS)-SCLC must have completed platinum-based chemotherapy and either definitive thoracic radiotherapy (including stereotactic body radiation therapy \[SBRT\] for early-stage T1-2 N0 M0 disease who do not undergo surgery) or definitive surgical resection; thoracic radiation in addition to definitive surgical resection is allowed at the discretion of the treating physician, but is not required. Patients with extensive-stage (ES)-SCLC must have completed platinum-based chemotherapy either with or without thoracic radiotherapy at the discretion of the treating physician * All adverse events from prior treatment must have resolved to =\< grade 2 (Common Terminology Criteria for Adverse Events \[CTCAE\] version 5.0) prior to randomization * Patient must have had a response to first-line therapy and no evidence of progression in opinion of the treating investigator. Systemic imaging (computed tomography \[CT\] or positron emission tomography \[PET\]/CT including the chest and abdomen) m…