Timing of Post-prostatectomy PSMA Imaging (TOPP)

March 3, 2026 updated by: University Health Network, Toronto

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

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

4

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G 2M9
        • Princess Margaret Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Surveillance
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
Standard of care salvage radiotherapy to the prostate bed which may include the lymph nodes.
No Intervention: Salvage radiotherapy
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?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Surveillance with delayed PSMA PET scan
Time Frame: 7 years
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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Health Network, Toronto

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 22, 2022

Primary Completion (Actual)

July 8, 2024

Study Completion (Actual)

July 8, 2024

Study Registration Dates

First Submitted

August 12, 2021

First Submitted That Met QC Criteria

August 12, 2021

First Posted (Actual)

August 17, 2021

Study Record Updates

Last Update Posted (Actual)

March 5, 2026

Last Update Submitted That Met QC Criteria

March 3, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 21-5040

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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