Molecular Imaging Informed Radiation Dose Escalation to Sites of Recurrent Disease and De-escalation to Uninvolved Areas in Salvage Radiotherapy Using SBRT for Prostate Cancer to Reduce Treatment Toxicity

NCT07515651 | Not Yet Recruiting Phase 2

• 1 other identifier: 25-6057
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single arm trial that is recruiting a total of 50 participants that have been diagnosed with prostate bed (where the prostate was taken out) or regional (surrounding lymph nodes) recurrence of a prostate cancer following surgery. Salvage radiation treatment represents the main treatment option, with long-term cure rates on the order of 70%. Currently, salvage radiation treatment to the prostate bed and the pelvic lymph nodes is delivered using external beam radiation therapy (EBRT) in 20-33 sessions, over 4-6.5 weeks. Potential study participants have undergone a PSMA PET scan, which has found recurrent cancer in the prostate bed or lymph nodes. This study will investigate personalizing your radiation treatment based on this information. Participants on this study will receive lower than standard radiation dose to areas of the surgical site which do not show evidence of disease on the scan. This personalized radiotherapy will be delivered in 5 treatments over two weeks, rather than the four to 6 weeks which is the current standard of care. Participants will have a routine history, blood collection for PSA and hormone levels, toxicity assessment, and EPIC-26 \& IPSS questionnaires at each follow-up visit. These will take place at 1, 3, 6, 12, 24, 36, and 60 months after radiation treatment.

Conditions

Prostate Cancer (Adenocarcinoma)

Outcome Measures

Primary Outcomes (1)

• Radiation-induced Acute Grade ≥2 Toxicity

  Acute (less than or equal to 90 days) toxicity will be evaluated by using prospective follow-up and grading according to the latest version of the Common Terminology Criteria for Adverse Events (CTCAE) v6.0.

  Baseline to 5-year follow up

Secondary Outcomes (4)

• Acute and Late GI and GU toxicities

  Estimated at 6 months and 2 years following treatment

• Local Recurrence

  Estimated at 2 years and 5 years following treatment

• Biochemical Disease Free Survival

  Estimated at 2 years and 5 years following treatment

• Patient-reported quality-of-life assessed by EPIC-26 and IPSS

  Baseline to 5-year follow-up

Study Arms (1)

Molecular Imaging Informed Radiation Dose Escalation and De-escalation

EXPERIMENTAL

Molecular imaging informed radiation dose escalation to sites of recurrent disease and de-escalation to uninvolved areas.

Radiation: Image-guided Radiotherapy

Interventions

Image-guided Radiotherapy RADIATION

* Molecular imaging informed radiation dose escalation to sites of recurrent disease and de-escalation to uninvolved areas with SBRT, 25Gy in 5 fractions to prostate bed +/- pelvic lymph nodes delivered every other day with a boost to PSMA avid disease of 35 Gy in 5 fraction * Treatment of pelvic lymph nodes and androgen deprivation therapy for 0-24 months at clinician discretion

Molecular Imaging Informed Radiation Dose Escalation and De-escalation

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years old.
• Histologically proven initial diagnosis of adenocarcinoma prostate cancer.
• Radical prostatectomy \> 6 months prior to commencing SBRT.
• Biochemical relapse with local and/or regional recurrence proven with PSMA PET
• ECOG 0-1.

You may not qualify if:

• Presence of para-aortic lymph nodes or distant metastasis.
• Chronic pelvic inflammatory disease.
• Contraindication for radiation treatment.
• Previous radiation treatment within the pelvis.

Sponsors & Collaborators

• University Health Network, Toronto: lead

Study Sites (1)

University Health Network - Princess Margaret Cancer Center

Toronto, Ontario, M5G 2M9, Canada

Location

MeSH Terms

Conditions

Prostatic Neoplasms; Adenocarcinoma

Interventions

Radiotherapy, Image-Guided

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type

Intervention Hierarchy (Ancestors)

Radiotherapy; Therapeutics

Central Study Contacts

Andrew McPartlin, MD

CONTACT

416-946-4501; andrew.mcpartlin@uhn.ca

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 31, 2026
• First Posted: April 7, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): October 1, 2034
• Study Completion (Estimated): October 1, 2034
• Last Updated: September 28, 2026

Record last verified: 2026-09

Locations

CA (1)