Inability to lie flat and still for treatment delivery despite anti-anxiety and/or pain medications Have the ability to tolerate required SBRT-related procedures (eg: lie flat and hold position for treatment) as determined by the treating physician Ability to tolerate radiation therapy (e.g. lie flat and hold position for treatment) Patients unable to lie flat comfortably for hours Inability to lie flat on a treatment table for > minutes Subjects unable to receive study treatment planning secondary to body habitus or inability to lie flat on the stomach for at least hour Subjects unable to receive study treatment planning secondary to body habitus or inability to lie flat on the stomach at length Ability to tolerate hypofractionated radiation therapy (e.g. lie flat and hold position) Inability to lie flat for > hour The subject is able to lie flat for up to minutes for imaging studies Ability to tolerate stereotactic body radiation therapy (e.g. lie flat and hold position for treatment) Unable to lie flat during or tolerate PET/MRI, PET/CT or SBRT Patient is unable to lie flat or has respiratory distress at rest. Inability to tolerate lying flat on treatment table for greater than minutes Ability to tolerate stereotactic body radiation therapy (e.g. lie flat and hold position for treatment) Patients who cannot lie flat for minutes Patients must be able to lie flat for at least minutes and fit on a PET-CT scanner Claustrophobia and/or inability to lie flat in magnetic resonance imaging (MRI) machine Unable to lie flat, still or tolerate a PET scan Unable to lie flat, still or tolerate a PET scan Unable to lie flat, still or tolerate a PET scan SUB-STUDY I: Unable to lie flat during or tolerate PET/CT SUB-STUDY II: Unable to lie flat during or tolerate PET/CT SUB-STUDY III: Unable to lie flat during or tolerate PET/CT Inability to lie flat for - minutes Unable to lie flat, still or tolerate a PET scan Inability to lay flat for at least consecutive hours Unable to lie flat during or tolerate PET/MRI Patients must be able to lie flat to obtain the functional scans or have blood access for blood samples Inability to lie flat for the duration of PET/CT and V/Q SPECT/CT (approximately minutes for each study) Patients who are unable to lie flat on the imaging systems long enough to permit imaging protocols to be performed Unable to lie flat during or tolerate PET/CT Inability to tolerate MRI (e.g., inability to lie flat for > hour) Unable to lie flat, still or tolerate a PET/CT scan Unable to lie flat, still or tolerate a PET scan Patients must be willing to lie flat on their back in the PET/CT scanner for up to hours to allow the imaging data to be obtained Any medical condition which impairs the ability to lie flat and without movement for minutes (e.g. cough, severe arthritis, etc.) Patients must be able to lie flat for at least minutes and fit on PET-CT scanner