NCT07391982

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

Dose De-escalation in Prostate Radiotherapy Using an MR-Linac in 2 Fractions

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 54 (estimated)
• Sponsor: The Netherlands Cancer Institute · Academic / Other
• Sex: Male
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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

• Prostate Cancer (Adenocarcinoma)

Interventions

Type	Name	Description
RADIATION	uniform dose radiotherapy	27 Gy dose in 2 fractions to the whole prostate+/- seminal vesicles with a 0mm PTV margin using MR-linac
RADIATION	De-escalated dose radiotherapy	The benign prostate +/- SV CTV will receive 20 Gy in 2 fractions with a 0mm PTV margin using MR-linac. The intraprostatic tumor masses (on MRI) will receive 27 Gy in 2 fractions. A 4mm GTV to PTV margin will be added to the in-traprostatic MR visible tumour to form PTV 27Gy.

Timeline

• Start date: 2025-11-17
• Primary completion: 2027-02-01
• Completion: 2028-12-01
• First posted: 2026-02-06
• Last updated: 2026-02-06

Locations

1 site across 1 country: Netherlands