Adaptive Radiotherapy for Safe Hypofractionation (ART-Hypo)

April 2, 2026 updated by: Centre hospitalier de l'Université de Montréal (CHUM)

Adaptive Radiotherapy for Safe Hypofractionation (ART-Hypo): A Bayesian Registry-Based Randomized Controlled Trial

This phase II, registry-based cohort-multiple randomized controlled trial (cmRCT) evaluates whether daily online adaptive radiotherapy (ART) enables the safe delivery of hypofractionated, iso-biologically equivalent (EQD2) external beam radiotherapy compared with standard-of-care (SOC) fractionation.

Conventional radiotherapy requires generous planning target volume (PTV) margins to account for inter-fraction anatomical variation, which increases radiation exposure to surrounding organs at risk (OARs) and may contribute to toxicity. Modern ART platforms using daily on-table imaging (kV-CBCT or MRI guidance) allow real-time contour adaptation and online plan re-optimization based on same-day anatomy. This approach enables margin reduction while maintaining target coverage and may permit safe hypofractionation.

Eligible patients enrolled in an institutional prospective registry will be randomized (1:1) to receive either SOC radiotherapy or hypofractionated ART across multiple pelvic disease strata (post-prostatectomy prostate cancer, intact prostate cancer, endometrial cancer, cervical cancer, and rectal cancer).

The primary objective is to demonstrate non-inferiority of hypofractionated ART compared with SOC in terms of cumulative incidence of Grade ≥2 toxicity (CTCAE v5). Secondary outcomes include acute and late toxicity, oncologic outcomes (progression-free survival, locoregional failure, distant metastases, overall survival), patient-reported outcomes, treatment efficiency, and dosimetric parameters.

A Bayesian monitoring framework with pre-specified safety and futility stopping rules will be used to ensure patient safety and clinical equipoise throughout the trial.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

264

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 Contact

Study Contact Backup

Study Locations

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

- Enrolled in PERa registry (CHUM CER 17.0.32), consented to contact for investigational trials, consented to serve as control, and randomly selected to be offered the experimental intervention.

Exclusion Criteria:

- For intact prostate stratum : 1. Contraindications to MRI (e.g., pacemaker, potentially mobile metal implant, claustrophobia). 2. Hip replacement, or other pelvic metalwork which causes significant artefact on MRI.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Standard-of-care Radiotherapy
Radiation: Standard-of-care Radiotherapy
Planned radiotherapy delivered according to physician discretion, without daily online contour adaptation or plan re-optimization prior to treatment delivery.
Experimental: Adaptive Hypofractionated Radiotherapy (ART-Hypo)
Radiation: Adaptive Hypofractionated Radiotherapy
Adaptive Radiotherapy (ART) in this study is a real-time, online daily adaptation approach in which high-resolution on-table imaging (kV-CBCT or real-time MRI) is performed prior to each fraction, with the treatment plan immediately recalculated or re-optimized using reduced PTV margins before delivery if needed, enabling safe hypofractionation through tighter margins.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Physician-reported Grade 2+ toxicity
Time Frame: 24 months
The primary endpoint is the cumulative incidence of physician-reported Grade 2+ toxicity (CTCAE v5) occurring within 24 months from the completion of radiotherapy.
24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression free survival
Time Frame: 24 months
24 months
Acute adverse effects
Time Frame: 3 months
3 months
EORTC QLQ-C30 Global Health Status / Quality of Life Score
Time Frame: 12 and 24 months
For all patients
12 and 24 months
EPIC-26 Domain Scores
Time Frame: 12 and 24 months
Specifically for prostate cancer strata
12 and 24 months
Time to distant metastases
Time Frame: 24 months
24 months
Treatment efficiency
Time Frame: Up to four weeks
Measured as the total time on the treatment table per fraction and the cumulative treatment time across all fractions.
Up to four weeks
Dosimetric Assessment
Time Frame: Up to four weeks
Up to four weeks

Collaborators and Investigators

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

Sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Investigators

  • Principal Investigator: Maroie Barkati, MD, Centre Hospitalier de l'Universite de Montreal (CHUM)

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 (Estimated)

May 1, 2026

Primary Completion (Estimated)

May 1, 2030

Study Completion (Estimated)

May 1, 2030

Study Registration Dates

First Submitted

March 3, 2026

First Submitted That Met QC Criteria

April 2, 2026

First Posted (Actual)

April 7, 2026

Study Record Updates

Last Update Posted (Actual)

April 7, 2026

Last Update Submitted That Met QC Criteria

April 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026-13479

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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