Timing of Post-prostatectomy PSMA Imaging

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

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05008900

Acronym

TOPP

Enrollment

Registered

2021-08-17

Start date

2022-03-22

Completion date

2024-07-08

Last updated

2026-03-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostate Cancer, Prostatectomy

Brief summary

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.

Interventions

RADIATIONSalvage radiotherapy

Standard of care salvage radiotherapy to the prostate bed which may include the lymph nodes.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

DIAGNOSTIC

Masking

NONE

Intervention model description

Feasibility

Eligibility

Sex/Gender

MALE

Age

18 Years to No maximum

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame	Description
Surveillance with delayed PSMA PET scan	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.

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 6, 2026