PRIMARY OBJECTIVE:
I. To evaluate the imaging performance of flotufolastat F-18 gallium (\[18F\]-rhPSMA) PET-CT imaging subsystem of the RefleXion Medical Radiotherapy System Device in patients with lesions detected on standard-of-care (SOC) \[18F\]-rhPSMA PET-CT on the same day.
SECONDARY OBJECTIVES:
I. To evaluate the frequency that SOC Posluma imaging will result in the ability to distinctly identify and separate PET activity from bladder activity to aid in the detection, lesion contouring, RT planning and RT delivery for intra-prostatic lesions, prostate bed lesions (salvage RT) or lesions near the bladder.
II. To evaluate the frequency that SOC Posluma imaging will result in a change in radiotherapy planning through either exclusion due to extra-pelvic metastatic disease or detection of disease that results in a modification of RT field coverage or dose.
III. Evaluate the potential for using the X1 RMRS PET used to generate an acceptable BgRT plan such that dosimetric parameters for the target and the nearby normal anatomy are met based on investigator assessment.
OUTLINE:
Patients receive SOC flotufolastat F-18 gallium intravenously (IV) and undergo PET-CT on study. Patients then undergo X1 RMRS PET-CT imaging-only session 120 minutes post-injection.
After completion of study intervention, patients are followed up within 72 hours of PET imaging-only session.
