Actively Recruiting

Phase Not Applicable
Age: 18Years +
MALE
NCT07391982

Dose De-escalation in Prostate Radiotherapy Using an MR-Linac in Two Fractions

Led by The Netherlands Cancer Institute · Updated on 2026-02-06

54

Participants Needed

1

Research Sites

158 weeks

Total Duration

On this page

Sponsors

T

The Netherlands Cancer Institute

Lead Sponsor

M

MRL Consortium

Collaborating Sponsor

AI-Summary

What this Trial Is About

The goal of this clinical trial is to find out whether lowering the radiation dose to parts of the prostate without visible tumor on MRI can reduce side effects while still effectively treating prostate cancer in men with low or intermediate-risk prostate cancer. The main questions it aims to answer are: * Does reducing the radiation dose to healthy prostate tissue lower the risk of bowel and urinary side effects? * Can we maintain good cancer control by keeping a high dose for MRI-visible tumor areas? Researchers will compare two treatment approaches: * One group receives a uniform high dose to the entire prostate. * The other group receives a lower dose to healthy prostate tissue and a high dose only to visible tumor areas. Participants will: * Receive two sessions of MRI-guided radiotherapy using an MR-Linac. * Complete questionnaires about urinary, bowel, and sexual health before and after treatment. * Have follow-up visits to monitor side effects and PSA levels for up to 2 years.

CONDITIONS

Official Title

Dose De-escalation in Prostate Radiotherapy Using an MR-Linac in Two Fractions

Who Can Participate

Age: 18Years +
MALE

Eligibility Criteria

Eligible

You may qualify if you...

  • Men aged 6518 years
  • Histological confirmation of prostate adenocarcinoma requiring radical radiotherapy
  • Gleason score 3+3, 3+4 or 4+3 (ISUP Grade groups 1, 2 or 3)
  • MRI-visible tumour(s) of PIRADS v2 grade 3 or higher, delineable on T2 and diffusion-weighted imaging �2b dynamic contrast-enhanced imaging, with tumour nodule �3c2.5 cm in maximal dimension and able to be boosted by treating clinician
  • MRI must be performed within 3 months of trial entry
  • MRI-defined lesion confirmed malignant on biopsies (any Gleason grade)
  • MRI stages mT1 and T2 or mT3a with 641 mm tumour outside gland AND otherwise favourable intermediate risk characteristics
  • PSA �3c20 ng/ml prior to starting androgen deprivation therapy
  • WHO Performance status 0-2
  • Ability to understand and willingness to sign informed consent
  • Ability/willingness to comply with patient reported outcome questionnaires throughout the study
Not Eligible

You will not qualify if you...

  • Contraindications to MRI (e.g., pacemaker, potentially mobile metal implant, claustrophobia)
  • IPSS Score �3e 19
  • High grade disease (GG3) occult to MRI-defined lesion
  • Prostate volume �3e90 cc
  • Comorbidities predisposing to significant toxicity (e.g., inflammatory bowel disease) or precluding long term follow up
  • Hip replacement or other pelvic metalwork causing artefact on diffusion-weighted imaging
  • Previous pelvic radiotherapy
  • Patients needing more than 6 months of androgen deprivation therapy due to disease parameters
  • Previous invasive malignancy within last 2 years excluding certain low-risk skin and bladder cancers or small renal masses on surveillance

AI-Screening

AI-Powered Screening

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Trial Site Locations

Total: 1 location

1

The Netherlands Cancer Institute

Amsterdam, Netherlands, 1066CX

Actively Recruiting

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Research Team

F

Floris Pos, MD, PhD

CONTACT

How is the study designed?

Study Type

INTERVENTIONAL

Masking

NONE

Allocation

RANDOMIZED

Model

PARALLEL

Primary Purpose

TREATMENT

Number of Arms

2

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