A Dosimetry Study of Lutetium (177Lu) rhPSMA-10.1 and Lutetium (177Lu) Vipivotide Tetraxetan (Pluvicto®) in Patients With Non-curative Metastatic Prostate Cancer

Inclusion Criteria: * Male patient aged ≥60 years old at Visit 1 (Screening). * Patient has non-curative PSMA-positive prostate cancer that has spread outside of the prostate gland and is undergoing or being planned for radioligand therapy. * At least 1 PSMA-positive lesion that can be outlined on PET or CT and ≥1 cm in the short axis measured on either modality, for the purpose of dosimetry. * Adequate normal organ function as demonstrated by: * Absolute neutrophil count ≥1.5 × 109/L * Platelets ≥100 × 109/L * Haemoglobin ≥9 g/dL * Total bilirubin \<2 × the institutional upper limit of normal (ULN). For patients with known Gilbert's Syndrome, ≤3 × ULN is permitted. * Alanine aminotransferase (ALT) or aspartate transaminase (AST) ≤3.0 × ULN or ≤5.0 × ULN for patients with liver metastases. * Estimated glomerular filtration rate (using Chronic Kidney Disease Epidemiology Collaboration Creatinine Equation \[2009\]) \>50 mL/min. * Willing to provide signed and dated written informed consent form (ICF) prior to any study specific procedures * Male patients must agree not to father children or donate sperm during the study and for at least 14 weeks after the last study treatment. Exclusion Criteria: * Known hypersensitivity to lutetium (177Lu) rhPSMA 10.1 or lutetium (177Lu) vipivotide tetraxetan, or any of the constituents. * Previous treatment with any radiopharmaceutical therapy in the 42 days or 5 half-lives prior to Visit 1 (Screening). * Any significant metallic implants or objects, which may in the opinion of the investigator, affect image quality and/or dosimetry calculations. * Severe claustrophobia, inability to lie flat or fit into the scanner, or any other inability to tolerate the SPECT/CT scan protocol * Any change to prostate cancer medication or new prostate cancer therapy, prostate cancer surgical procedure within 42 days prior to screening or during the study. * Any medical or psychiatric condition, including rapidly progressive prostate cancer, that in the investigator's judgment, makes the patient unsuitable for the study * Participation in other studies involving other IMPs within 42 days or 5 half lives (whichever is longer) prior to Visit 1 (Screening) and/or during study participation