Patients who are unable to undergo MRI Unable to undergo brain MRI Patients must be able to have MRI scans Unable to undergo MRI scans Unable to undergo brain MRI Subject who cannot undergo MRI. Ability to undergo MRI scanning with contrast Participants who cannot undergo a brain MRI Must be able to undergo serial MRI scans for response evaluation Patient must be able to undergo MRI and PET scans Unable to undergo MRI scans with contrast Unable to undergo MRI scan (e.g., pacemaker) Patients unable to undergo MRI are not eligible. Unable to undergo MRI of the brain (i.e. pacemaker or any other contraindication for MRIs) Able to undergo brain MRI with and without contrast Patients who are unable to obtain MRI Patient unable to have an MRI of the brain Ability to undergo MRI evaluation. Patients unable to undergo MRI of the brain Unable to undergo MRI of the spine Inability to undergo brain MRI due to medical or personal reasons. Patients who are allergic to MRI contrast medium or unable to undergo MRI for any other reason. Inability to undergo MRI due to personal or medical reasons Inability to undergo MRI due to personal or medical reasons (Arm B) Must be able and willing to undergo two MRI scans, before study treatment begins and shortly after first dose of radiation (only mandatory for first patients who have no contra-indications for MRI Patients must be able to undergo an MRI with contrast Patients unable to undergo an MRI with contrast Subject is able to undergo either an MRI or administration of contrast agent for CT Inability to undergo MRI with and without contrast administration Contraindication to contrast enhanced MRI (i.e. unable to undergo follow-up imaging) The subject is unable to undergo MRI scan (e.g., has pacemaker) Subjects unable to undergo an MRI with contrast Unable to undergo MRI scans (e.g., embedded ferromagnetic metal or pacemakers) Any contra-indications to undergo MRI imaging. Unable to undergo MRI MRI of the brain (or contrast CT scan of the brain if patients are unable to undergo MRI) must be obtained in patients with symptoms suggesting possible central nervous system (CNS) metastatic disease; neuroimaging is recommended but not required in asymptomatic patients Patients who are unable to undergo MRI Patients unable to undergo MRI exams. Inability to undergo MRI evaluation for treatment planning and follow-up Unable to undergo imaging by either CT scan or MRI Unable to undergo MRI of the spine Patients unable to undergo an MRI of the brain with contrast. The subject is unable to undergo MRI scan (eg, has pacemaker) Patients must be able to undergo contrast enhanced magnetic resonance imaging (MRI) scans (or contrast enhanced computed tomography [CT] scans for patients unable to tolerate MRI) Inability to undergo MRI Unwilling or unable to undergo a MRI or CT Scan per study protocol requirements Inability to undergo MRI due to personal and medical reasons Patient must be willing and able to undergo MRI as outlined in protocol Able to undergo brain MRI scans Patient must be able to undergo MRI with and without contrast; patients who are unable to undergo MRI are ineligible Must be able to undergo MRI of abdomen (spleen and liver). Patients who are contra indicated for MRI may be enrolled and evaluated by CT scan at the discretion of the Sponsor. Patients unable to undergo contrast-enhanced MRI. Must be able to undergo MRI and have at least one measurable intracranial lesion for which specific criteria have to be met. Unable to undergo brain MRI due to medical or personal reasons Inability to undergo MRI evaluation for treatment planning and follow-up Patients must be able to undergo contrast enhanced MRI scans (or contrast enhanced computed tomography [CT] scans for patients unable to tolerate MRI) Patients scheduled to undergo screening breast MRI with contrast Women too claustrophobic to undergo MRI Participant is able to undergo radiographic evaluation with CT or MRI Able to undergo standard MRI scans with contrast agent Able to undergo standard MRI scans with contrast agent before enrollment and after treatment Patients who are unwilling or unable to undergo MRI including patients with contraindications to MRI such as the presence of cardiac pacemakers or non-compatible intracranial vascular clips, claustrophobia, inability to lie flat for the duration of the study etc Patients who are unwilling or unable to undergo MRI including patients with contraindications to MRI such as the presence of cardiac pacemakers or non-compatible intracranial vascular clips, claustrophobia, inability to lie flat for the duration of the study etc Patient must be able to undergo MRI and PET scans Patient must meet standard MRI guidelines and be able and willing to undergo MRI Participants who are unable to undergo MRI because of documented contra-indications for contrast-enhanced MRI, including but not limited to renal failure Patient must meet standard MRI guidelines and be able and willing to undergo MRI Patient must be able to undergo MRI and PET scans Subjects must be able to undergo MRI imaging without anesthesia Patients who are unable to undergo MRI scanning due to exclusion by University Hospitals Case Medical Center (UHCMC) MRI restriction policies as mentioned in the standard UHCMC MRI informed consent form Patients unwilling or unable to undergo MR imaging, including patients with contraindications to MRI, such as cardiac pacemakers or non-compatible intracranial vascular clips Patients unwilling or unable to undergo MR imaging, including patients with contraindications to MRI, such as cardiac pacemakers or non-compatible intracranial vascular clips Inability to undergo or cooperate with an MRI or PET scan (e.g., claustrophobia, metal implant) Participants must be able to undergo MRI scan Able to undergo contrast enhanced MRI Patients unwilling or unable to undergo MR imaging, including patients with contra-indications to MRI, such as cardiac pacemakers or non-compatible intracranial vascular clips Patients who are too claustrophobic to undergo MRI or PET imaging Patients must agree to undergo serial multiparametric MRI and MRI-guided biopsy Unable to undergo MRI scans with contrast (e.g. cardiac pacemaker, defibrillator, kidney failure) Unable to undergo MRI scans with contrast (e.g. cardiac pacemaker, defibrillator, kidney failure) Patients who are unwilling or unable to undergo MRI including patients with contra-indications to MRI such as the presence of cardiac pacemakers or non-compatible intracranial vascular clips Patients who are too claustrophobic to undergo MRI or PET imaging Patients who cannot undergo MRI imaging due to MRI exclusion criteria Patients who are unable to undergo MRI Patients with contraindications to MRI (e.g., pacemaker, claustrophobia, etc.) (MR/TRUS only) ---Patients with renal dysfunction are excluded due to their inability to undergo contrast enhanced MRI Patients who are unwilling or unable to undergo MRI including patients with contraindication to MRI such as the presence of cardiac pacemakers or non-compatible intracranial vascular clips, claustrophobia, inability to lie flat for the duration of the study etc Patients unwilling or unable to undergo the ecoil placement or multiparametric MRI exam Must be able to undergo MRI scans Patients who are unable to undergo MRI imaging Patients need not undergo a baseline MRI prior to enrollment For patients who choose to undergo MRI imaging, hypersensitivity to MRI IV contrast media not suitable for pre-medication For patients who choose to undergo MRI imaging, patients who are ineligible for an MRI with contrast based on radiology department screening