Timing of Post-prostatectomy PSMA Imaging

Study Overview
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Brief Summary
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The investigators will randomize patients presenting with early BCR with a negative baseline PSMA PET/CT, to upfront SRT or surveillance. Early BCR is defined as a PSA relapse of >0.1 to <0.3 ng/mL. Patients in the surveillance arm will be monitored with PSA every 3 months. A repeat PSMA PET/CT will be undertaken when the PSA reaches a target level of >0.5 to <1.0 ng/mL. Both early radiation treatment and surveillance with repeat PSMA PET/CT imaging are within patterns of practice locally; therefore, the investigators believe that there is clinical equipoise on this subject.

Official Title
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A Phase II Randomized Feasibility Study Comparing Early Salvage Radiotherapy Versus Surveillance With Delayed Repeat PSMA PET/CT Imaging in Patients Presenting With Early Biochemical Relapse of Prostate Cancer Following Radical Prostatectomy

Conditions
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Prostate Cancer, Prostatectomy

Intervention / Treatment
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* Radiation: Salvage radiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Histologically-proven prostate cancer pT1-T4 pN0/Nx cM0 PSA at BCR >0.1 - <0.3 ng/mL post-radical prostatectomy PSMA PET/CT negative at BCR post radical prostatectomy Planned SRT to prostate bed +/- pelvic lymph nodes ECOG 0 or 1 Age ≥ 18 years Informed consent: All patients must sign a document of informed consent indicating their understanding of the investigational nature and risks of the study before any protocol related studies are performed. Exclusion Criteria: Active or post prostatectomy androgen deprivation use Previous pelvic radiotherapy Other contraindications to radiotherapy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Feasibility
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Surveillance<br>Patients with early biochemical relapse of prostate cancer following radical prostatectomy who have a PSA greater than or equal to 0.1 to less than 0.3 ng/mL with negative PSMA PET/CT will go on surveillance. Routine PSA will be conducted and a repeat PSMA PET/CT imaging will be conducted when the PSA rises to greater than 0.5 to less than 1.0 ng/mL. | Radiation: Salvage radiotherapy<br>* Standard of care salvage radiotherapy to the prostate bed which may include the lymph nodes.<br>|
| No Intervention: Salvage radiotherapy<br>Patients with early biochemical relapse of prostate cancer following radical prostatectomy who have a PSA of greater than or equal to 0.1 to less than 0.3 ng/mL with negative PSMA PET/CT will receive salvage radiotherapy to the prostate bed. This radiotherapy may or may not include the pelvic lymph nodes. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surveillance with delayed PSMA PET scan | This study will assess the feasibility of surveillance with delayed repeat PSMA PET/CT in patients with BCR of prostate cancer following radical prostatectomy with negative baseline PSMA PET/CT. A treating physician questionnaire will be completed prior to screening and enrollment, as well as PSA results every three months for surveillance patients. | 7 years |