Addition of 177Lu-PSMA-617 in the treatment of hormone sensitive metastatic prostate cancer: a prospective pilot study.

The current recommendations for treatment of metastatic prostate carcinoma are to combine the use of Androgen Deprivation Therapy (ADT) with other agents such as taxanes, antiandrogens (Abiraterone, Enzalutamide or Apalutamide). 177Lu-PSMA-617 is a recently emerging therapeutic radiopharmaceutical which has shown promising results in various phase 2 trials in the treatment of metastatic castration resistant prostate cancer patients - most evident in reducing the therapy related adverse effects. We expect the addition of 177Lu-PSMA-617 therapy to provide better clinical outcomes and quality of life. Once diagnosis of metastatic carcinoma prostate is established, the patients will be screened using inclusion/exclusion criteria, and will undergo a baseline salivary scintigram. Serum PSA values will be obtained pre-treatment from clinical records and serial values will be obtained 4 weekly until week 20 (that is, 12 weeks from the second cycle of 177Lu-PSMA-617). Patient’s quality of life will be assessed using FACT-P questionnaire whose responses are obtained on the day of the first cycle of 177Lu-PSMA-617 before therapy, and after 6 weeks of the last cycle of 177Lu-PSMA-617. Serum PSA values of historical control group/literature-available control group of patients with metastatic hormone sensitive prostate cancer treated with ADT plus abiraterone; will be utilized. A systematic review will be performed and outcome variables such as PSA response will be compared descriptively. If follow-up PET/CT studies with 68-Ga-PSMA are available, as part of routine clinical follow up by the treating physician, they will be commented upon.