RecruitingPhase 2ProcedurePositron Emission Tomography (PET) Guided Stereotactic Body Radiation Therapy for the Treatment of Oligoprogressive Non-small Cell Lung Cancer, Melanoma, and Renal Cell CarcinomaThis phase II trial tests the safety of positron emission tomography (PET) guided stereotactic body radiation therapy (SBRT) and how well it works to treat non-small cell lung cancer (NSCLC), melanoma, and renal cell carcinoma (RCC) that has up to 5 sites of progression (oligoprogression) compared to standard SBRT. SBRT uses special equipment to position a patient and deliver radiation to tumors with high precision. This method may kill tumor cells with fewer doses over a shorter period and cause less damage to normal tissue. A PET scan is an imaging test that looks at your tissues and organs using a small amount of a radioactive substance. It also checks for cancer and may help find cancer remaining in areas already treated. Using a PET scan for SBRT planning may help increase the dose of radiation given to the most resistant part of the cancer in patients with oligoprogressive NSCLC, melanoma, and RCC.