Moderate Hypofractionated Boost to the Prostate With Pelvic RT in High Risk Prostate Cancer (MOB-RT)

This is a single-arm phase II prospective trials that is recruiting 100 participants. The study population that is being investigated are patients with localized high-risk or node-positive prostate cancer. Participants will receive external beam radiotherapy as a moderately hypofractionated boost to the prostate with pelvic radiation therapy. Androgen deprivation therapy will be prescribed at the discretion of the treating physician as per standard of care.

Study Overview

• Status: Recruiting
• Conditions: Prostate Cancer
• Intervention / Treatment: Radiation: Moderate hypofractionated boost to the prostate with pelvic RT (external beam radiotherapy)

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rachel Glicksman, MD; Phone Number: 416-946-4486; Email: rachel.glicksman@rmp.uhn.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 2M9
      • Recruiting
      • Princess Margaret Cancer Center
      • Contact: Rachel Glicksman, MD; Phone Number: 416-946-4483; Email: rachel.glicksman@rmp.uhn.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age > 18 years.
• Able to provide informed consent.
• Histologic diagnosis of prostate adenocarcinoma.
• ECOG performance status 0-1.
• High-risk localized disease by NCCN criteria (>cT3, Grade group >4, or PSA >20 ng/mL) or clinical N1 disease.
• Clinical M0 by conventional imaging (computed tomography (CT) and bone scan (BS)) and/or molecular imaging (prostate specific membrane antigen (PSMA)- positron emission tomography (PET))

Exclusion Criteria:

• Prior pelvic radiotherapy.
• Contraindications to radiotherapy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Moderate Hypofracitonated Boost to the Prostate with Pelvic Radiation Therapy; External beam radiotherapy- 60 Gy in 20 fractions to the prostate, 48 Gy in 20 fractions to the pelvis, 68 Gy in 20 fraction optional boost to prostatic dominant intraprostatic lesion, 55 Gy in 20 fraction optional boost to involved pelvic lymph nodes	Radiation: Moderate hypofractionated boost to the prostate with pelvic RT (external beam radiotherapy); External beam radiotherapy- 60 Gy in 20 fractions to the prostate, 48 Gy in 20 fractions to the pelvis, 68 Gy in 20 fraction optional boost to prostatic dominant intraprostatic lesion, 55 Gy in 20 fraction optional boost to involved pelvic lymph nodes

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute Grade >2 Gastrointestinal 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) v5.0.	Baseline to 5-year follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient-reported quality-of-life assessed by EPIC-26	Patient-Reported Quality of Life will be assessed at baseline and at each follow-up visit (3-weeks post intervention then every 6 months until 5 years, or more frequently if clinically necessary) using the following assessment questionnaires: 26-Item Expanded Prostate Cancer Index Composite (EPIC-26)	Baseline to 5-year Follow-up
Measure the severity of lower urinary tract symptoms during the study	Patient-Reported symptoms will be assessed at baseline and at each follow-up visit (3-weeks post intervention then every 6 months until 5 years, or more frequently if clinically necessary) using the following assessment questionnaires: International Prostate Symptom Score (IPSS)	Baseline to 5-year Follow-up
Graded criteria based on CTCAE version 5.0 for acute genitourinary toxicity and late genitourinary and gastrointestinal toxicity	Acute (less than or equal to 90 days) and long-term (greater than 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) v5.0.	Baseline to 5-year Follow-up
Measure of oncologic outcomes	Time to development of castrate-resistant prostate cancer (biochemmical or ardiographic progression while having castrate levels of testosterone)	Baseline to 5-year Follow-up
Measure of oncologic outcomes	Biochemical control rate will be assessed at baseline and at each follow-up visit (3 weeks after treatment then every 6 months until 5 years or more frequently if clinically necessary) by the blood level of prostate-specific antigen (PSA) levels	Baseline to 5-year Follow-up
Measure of onocologic outcomes	Radiographic control rate will be assess at baseline and weekly during the radiotherapy intervention using cone beam CT or bone scan.	Baseline to 5-year Follow-up
Prostate cancer specific survival based on death from prostate cancer	Safety will be evaluated by recording prostate cancer mortality at follow-up visits (3-weeks post intervention then every 6 months until 5 years, or more frequently if clinically necessary)	Baseline to 5-year Follow-up
Overall survival	Safety will be evaluated by recording overall mortality at follow-up visits (3-weeks post intervention then every 6 months until 5 years, or more frequently if clinically necessary).	Baseline to 5-year Follow-up

Collaborators and Investigators

• Sponsor: University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Actual): July 18, 2022
• Primary Completion (Estimated): April 1, 2030
• Study Completion (Estimated): April 1, 2030

Study Registration Dates

• First Submitted: March 15, 2022
• First Submitted That Met QC Criteria: April 5, 2022
• First Posted (Actual): April 6, 2022

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 3, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: prostate cancer; hypofractionation; high-risk prostate cancer; high risk prostate cancer; node positive prostate cancer; nod-positive prostate cancer
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Prostatic Neoplasms
• Other Study ID Numbers: 22-5218

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No