KV-CBCT and Ultrasound Imaging in Guiding Radiation Therapy in Patients With Prostate, Liver, or Pancreatic Cancer

PRIMARY OBJECTIVES: I. To investigate the feasibility of combining on-board cone beam computed tomography (CBCT) with ultrasound imaging to overcome the shortcomings of CBCT or ultrasound imaging alone for imaging guided radiotherapy delivery. OUTLINE: Patients undergo ultrasound imaging prior to and during radiation therapy. Patients also undergo kilo-voltage cone beam computed tomography prior to radiation therapy. Update (2021/02/04): Removed secondary outcome "Incidence of Adverse Events Related to the Ultrasound Probe". Per PI: Study initially intended to involve a non-FDA approved probe for use with liver patients but removed this section.