RefleXion PET/CT Imaging Performance in Patients With Various Malignancies

This clinical trial examines RefleXion Medical Radiotherapy System (RMRS) imaging to the standard of care (SOC) fludeoxyglucose F-18 (\[18F\]-FDG)- positron emission tomography (PET)-computed tomography (CT) imaging in patients with various cancers (malignancies). PET is an established imaging technique that utilizes small amounts of radioactivity attached to very minimal amounts of tracer, in the case of this research, \[18F\]-FDG. Because some cancers take up \[18F\]-FDG, cancer cells can be seen with PET. CT utilizes x-rays that traverse body from the outside. CT images provide an exact outline of organs and potential inflammatory tissue where it occurs in patient's body. The RefleXion system is designed to facilitate delivery of biology-guided radiotherapy (BgRT). The RMRS uses PET emissions to guide radiotherapy delivery in real-time and has been studied for use with FDG (which is an agent used in standard PET-CT scans that targets glucose). Information gathered from this study may help researchers to improve PET-CT imaging on the RefleXion system. This information will be used in the future to improve planning and delivery of radiotherapy that will target (in real time) the signal released from the \[18F\]-FDG-PET-CT tracer. Comparing the imaging from the standard of care \[18F\]-FDG-PET-CT with the \[18F\]-FDG imaging from RMRS may help improve the quality of the imaging captured and determine if imaging can be done on the RMRS at the same time as planning for radiation therapy, which would reduce the number of scans needed to plan for radiation for cancer.

Inclusion Criteria: * Documented informed consent of the participant and/or legally authorized representative * Age: \>= 21 years * Patients with malignancies (abdominal/pelvic/thoracic/head and neck/breast tumors) undergoing SOC \[18F\]-FDG PET-CT for diagnostic and/or radiotherapy planning purposes * Patients should be scheduled for \[18F\]-FDG PET-CT prior to study entry Exclusion Criteria: * Known psychiatric or substance abuse disorder that would interfere with conduct of the study * Patient weight exceeding the weight limit (450 pounds) outlined per X1 RMRS specifications sheet * Lung parenchymal and bone tumors will be excluded as their imaging characteristics were evaluated in a previous study