3.1. Inclusion Criteria  Greater than or equal to 18 years of age Pathologically confirmed diagnosis of cancer, including, but not limited to non-small cell lung cancer, breast, prostate, renal cell, melanoma, gastrointestinal, sarcoma, thyroid, head and neck primary, and carcinoma of unknown primary Signed informed consent Willing to undergo 2 MRI simulations in one or multiple sessions, one with immobilization device, and the other without. Patients undergoing spinal SBRT 3.2. Exclusion Criteria  a. Patient with a relative or absolute contraindication to MRI (such as pacemaker, etc.) b. Patients with significant instrumentation or cement at the site of interest causing artifact c. Inability to tolerate with immobilization device for greater than 30 minutes