Two TraCer PositROn EmiSSion Tomography ComBination for Efficacy EstimatiOn of Prostate Specific Membrane Antigen Radioligand Therapy in Patients With Metastatic Prostate Cancer

Inclusion Criteria: * Male * Age 18 years or older * Documented metastatic adenocarcinoma of the prostate * Under active medical oncology care * ECOG performance status 0 - 3, inclusive * Able to understand and provide written informed consent * Able to tolerate the physical requirements of two PET/CT scans including lying for up to 30 minutes * Progressive disease on any of: bone scan, CT, MRI or serum PSA as judged by the investigator * Serum prostate specific antigen ≥ 1 ng/ml at baseline or CT/MRI soft-tissue measurable disease as per RECIST v1.1 * Failed, failing, refused, no access to or not eligible for any approved prostate cancer therapies including but not limited to: ADT, NAAD (e.g., abiraterone, enzalutamide, darolutamide or apalutamide), docetaxel, cabazitaxel, radium-223 and oligometastatic RTX * Life expectancy of at least 3 months as judged by the investigator Exclusion Criteria: * Medically unstable (e.g. acute cardiac or respiratory distress or hypotensive) * Exceeding the weight limit of the PET/CT bed (approximately 400 lbs.) or who cannot fit through the PET/CT bore (approximately 70 cm diameter) * Unmanageable claustrophobia * Prior failure of PSMA RLT * Prior hemi-body irradiation * Impaired organ function as evidenced by any of the following laboratory values: * Absolute neutrophil count \< 1.5 x109/L * Platelet count \< 75 x109/L * Hemoglobin \< 85 g/L * Albumin \< 2.5 g/dL (25 g/L) * Total bilirubin \> 2 x ULN (unless in instances of Gilbert's disease) * AST or ALT \> 2.5 x ULN (or \> 5.0 x ULN in the presence of liver metastases)