Pilot Study of Dose Escalation in Prostate Radiotherapy Using the MR-Linac (DESTINATION-MRL)

What this study is about

This study is a single centre feasibility trial. The trial will recruit men with intermediate risk localised prostate cancer who will all receive targeted dose (escalated/de-escalated dose directed by MRI) 5 fraction SBRT to the prostate. Trial Objectives are: 1. Primary To develop a 5 fraction de-escalated dose SBRT protocol capable of reducing side effects 2. Secondary * To assess levels of acute GU and GI toxicity (CTCAE) * To assess levels of late GU and GI toxicity (CTCAE) * To assess late sexual quality of life (expanded EPIC, IIEF-5) * To assess biochemical relapse-free survival at 2

Who can join (things the study team will check)

✅ You may be able to join if…

• Men aged ≥18 years
• Histological confirmation of prostate adenocarcinoma requiring radical radiotherapy
• Gleason score 3+3, 3+4 or 4+3 (Grade groups 1, 2 or 3)
• MRI stage T2 or less (as staged by AJCC TNM 2018)
• MRI-visible tumour(s) of PIRADS v2 grade 3 or higher on T2 and diffusion-weighted imaging and/or dynamic contrast-enhanced imaging (multiparametric MRI or mpMRI) with concordant pathology
• Tumour nodule visible on MRI occupying <50% of prostate on any axial slice and <50% prostate volume
• PSA <20 ng/ml prior to starting ADT (if applicable)
• Short course (< 6 months) concurrent androgen deprivation therapy (antiandrogens or LHRH analogues) allowed though not mandated as per the discretion of the treating physician.
• WHO Performance status 0-2
• Ability of the participant understand and the willingness to sign a written informed consent form.
• Ability/willingness to comply with the patient reported outcome questionnaires schedule throughout the study.

🚫 You may not be able to join if…

• Contraindications to MRI (e.g. pacemaker, potentially mobile metal implant, claustrophobia)
• IPSS 19 or higher
• High grade disease (GG3) occult to MRI-defined lesion
• Post-void residual >100 mls, where known
• Prostate volume >90cc
• Comorbidities which predispose to significant toxicity (e.g. inflammatory bowel disease) or preclude long term follow up
• Unilateral or bilateral total hip replacement, or other pelvic metalwork which causes artefact on diffusion-weighted imaging
• Previous pelvic radiotherapy
• Patients needing >6 months of ADT due to disease parameters as per the discretion of the treating physician
• Previous invasive malignancy within the last 2 years excluding basal or squamous cell carcinomas of the skin, low risk non-muscle invasive bladder cancer (assuming cystoscopic follow up now negative) or small renal masses on surveillance.

Where this trial is running

• Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Who to contact

Danny Vesprini, M.D. · 416-480-4806 · Danny.Vesprini@sunnybrook.ca

It's completely normal to call and ask questions before deciding anything. Mention the study ID: NCT06177093.