A Pilot Study of Dose dE-eScalaTion IN prostATe radIOtherapy usiNg the MRL

NCT06284304 | Active Not Recruiting

• 1 other identifier: N22DES
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Trial design: A single centre phase II non-randomised study Trial population: Men with intermediate risk localised prostate cancer Recruitment target: 20 patients in total Trial objectives:

• Primary To develop a 5 fraction de-escalated dose SBRT protocol capable of reducing side effects
• 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 years Trial treatment: All radiotherapy will be delivered on the MR-linac. Intraprostatic dose will be varied according to risk of local recurrence, based on mpMRI, PSA and histology. The whole prostate will receive 30 Gy in 5 fractions and the GTV plus intra-prostatic margin will receive an isotoxic 45 Gy prescription.

Conditions

Prostate Cancer

Keywords

Radiotherapy; De-escalation; Prostate cancer; MR-Linac

Outcome Measures

Primary Outcomes (1)

• Technical feasibility of treating prostate cancer with toxicity minimising radiotherapy on a MR-linac

  To establish the technical feasibility of treating prostate cancer with tumour-escalated/normal prostate de-escalated dose radiotherapy on an MR-linac. Feasiblity is defined as coverage of GTV boost D90% \>42Gy on the post-treatment imaging.

  after 1,5 week of treatment

Secondary Outcomes (6)

• Acute GU toxicity

  within 90 days after first radiation treatment

• Acute GI toxicity

  within 90 days after first radiation treatment

• Late GU toxicity

  After at least 90 days after the first radioation treatment up to 2 years

• Late GI toxicity

  After at least 90 days after the first radioation treatment up to 2 years

• PROMs

  2 years

Study Arms (1)

Experimental radiotherapy treatment

EXPERIMENTAL

SBRT 5x30Gy of whole prostate and isotoxic 45 Gy GTV plus intra-prostatic margin

Radiation: De-escalated radiotherapy

Interventions

De-escalated radiotherapy RADIATION

5 fraction de-escalated dose SBRT protocol

Experimental radiotherapy treatment

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify 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 with concordant pathology
• Dominant lesion \<50% of prostate on any axial slice and \<50% total prostate volume
• PSA \<20 ng/ml prior to starting ADT
• Patients can be concurrently treated with androgen deprivation therapy if this would be standard of care. LHRH analogues or Bicalutamide are permitted. ADT is not mandatory where this would usually be omitted.
• 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 qualify 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.
• 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

Sponsors & Collaborators

• The Netherlands Cancer Institute: lead

Study Sites (1)

Netherlands Cancer Institute

Amsterdam, 1066CX, Netherlands

Location

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Study Officials

• Floris Pos, MD PhD

  The Netherlands Cancer Institute

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 5, 2024
• First Posted: February 28, 2024
• Study Start: February 29, 2024
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 2, 2027
• Last Updated: February 4, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

NL (1)