Randomized Trial of PSMA PET Scan Before Definitive Radiation Therapy for Prostate Cancer

Phase 3 Randomized Trial Of PSMA PET Prior to Definitive Radiation Therapy for Unfavorable Intermediate-Risk or High-Risk Prostate Cancer [PSMA dRT]

This randomized phase III trial studies the success rate of definitive radiation therapy (dRT) for prostate cancer (PCa) with or without planning based on PSMA PET. PSMA- PET-based dRT, may improve radiation therapy planning and patient selection for dRT, and potentially improve its outcome compared to dRT without PSMA PET (standard dRT).

PRIMARY OBJECTIVE:

I. To compare the outcome of patients with unfavorable intermediate (IR) and high-risk (HR) prostate cancer (PCa) after standard dRT versus prostate-specific membrane antigen (PSMA) positron emission tomography (PET)-based dRT.

OUTLINE: Patients are randomized to 1 of 2 arms. In both arms, no other primary treatment should be given before RT.

Arm I: Patients do not undergo PSMA PET for dRT planning. Patients undergo standard of care dRT at the discretion of the treating radiation oncologist.

Arm II: Patients undergo PSMA PET for dRT planning. Patients then undergo dRT at the discretion of the treating radiation oncologist, who receives the PSMA PET result and images.

After completion of dRT, clinical follow-up of patients with their treating radiation oncologist will be obtained for 5 years. The investigators will rely on the medical records obtained from the treating physicians as the primary source of outcome data.

Inclusion Criteria:

• Adult male 18 years or older

• Histopathologically-proven PCa

• Unfavorable IR to HR disease:

  • Prostate specific antigen (PSA) >= 10 ng/mL
  • Or cT-stage >= 2b
  • Or Gleason grade 3 (4+3=7) or higher
  • Or Gleason grade 2 (3+4=7) AND >= 50% positive biopsy cores
  • Or Decipher Score >= 0.45

• Treating radiation oncologist intends to incorporate PSMA PET findings into the radiotherapy plan, if patient undergoes PSMA PET (intervention arm 2)

• Provision of signed and dated informed consent form

• Stated willingness to comply with all study procedures and availability for the duration of the study

Exclusion Criteria:

• Less than 18 years old at the time of investigational product administration
• Extra-pelvic metastasis (M1 disease) on any imaging or biopsy done before randomization
• Prior PSMA PET
• Prior pelvic RT
• Contraindications to radiotherapy (including active inflammatory bowel disease)
• Concurrent or prior surgery or systemic therapy for PCa at the time of randomization