NCT07830511Not yet recruitingPhase 3
RIsk aDapted Stereotactic Radiotherapy vs. standarD of Care Radiotherapy in Patients With Prostate Cancer in the Adjuvant or saLvage sEtting With or Without Lymph Node Irradiation (RIDDLELN) - A Phase III Trial
Source: ClinicalTrials.gov · Last updated 21 Sept 2026
Brief summary (registry, in English)
The goal of this clinical trial is to determine whether stereotactic body radiotherapy (SBRT) delivered in five fractions is non-inferior to standard-of-care mildly hypofractionated radiotherapy in terms of patient-reported quality of life in adults with prostate cancer who require adjuvant or salvage radiotherapy after radical prostatectomy. The trial includes patients with or without a macroscopic recurrence in the prostate bed and allows irradiation of the regional lymphatic drainage when clinically indicated. The main questions it aims to answer are: * Is SBRT non-inferior to standard-of-care radiotherapy regarding urinary (GU) quality of life, measured by the change in the EPIC-26 GU domain score from baseline to 24 months after radiotherapy? * Is SBRT non-inferior to standard-of-care radiotherapy regarding bowel (GI) quality of life, measured by the change in the EPIC-26 GI domain score from baseline to 24 months after radiotherapy? Researchers will compare SBRT delivered as 6 Gy × 5 fractions to the prostate bed with standard-of-care radiotherapy delivered as 2.625 Gy × 20 fractions (total dose 52.5 Gy) to determine whether the substantially shorter SBRT treatment provides non-inferior patient-reported urinary and bowel outcomes. When clinically indicated, treatment of the lymphatic drainage and a simultaneous integrated boost to macroscopic recurrence or involved lymph nodes may also be delivered. Participants will: * Be randomly assigned in a 1:1 ratio to receive either five-fraction SBRT or 20-fraction standard-of-care radiotherapy. * Receive radiotherapy to the prostate bed, with additional irradiation of the regional lymphatic drainage and/or a boost to macroscopic disease or involved lymph nodes when clinically indicated. * Complete questionnaires assessing quality of life, urinary symptoms, and sexual function, including EPIC-26, IPSS, and IIEF-5. * Undergo clinical assessments, PSA measurements, assessment of treatment-related adverse events, and radiological imaging when clinically indicated. * Attend follow-up assessments at 3, 6, 12, 18, and 24 months after radiotherapy and then annually for up to 5 years. A total of 206 participants are planned for the trial. In addition to the primary quality-of-life outcomes, researchers will assess acute and late toxicity, biochemical recurrence-free survival, progression-free survival, time to further anti-cancer therapy, prostate cancer-specific survival, and overall survival.
- Status (registry)
- Not yet recruiting
- Phase (registry)
- Phase 3
- Study type
- Interventional
- Enrollment
- 206 (estimated)
- First submitted
- 15 Sept 2026
- Start date
- 1 Sept 2026
- Primary completion date
- 1 Sept 2031
- Lead sponsor
- Robert Förster
- Diseases
- Prostate cancer
- NCT number
- NCT07830511
What you commit to
- Study type: Interventional · Phase 3
- Planned participants: 206
- From 1 Sept 2026 to the primary completion date, 1 Sept 2031
- No sites listed in no country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Prior radiotherapy to the intended treatment site
Other illness
- Inability to follow the procedures of the study (e.g. due to language problems, psychological disorders, dementia)
- Comorbidities which predispose to significant radiotherapy toxicities (e.g. inflammatory bowel disease), at the discretion of the treating physician
Other
- Presence of distant metastases (M1a is not an exclusion criterion)
Who the study is looking for
- Confirmed prostate cancer treated with radical prostatectomy (≥ 6 months since radical prostatectomy)
- Indication for adjuvant or salvage radiotherapy (e.g. persisting or rising PSA, macroscopic recurrence, R1 resection, pT3b) at the discretion of the treating physician
- Androgen deprivation therapy allowed at the discretion of the treating physician
- WHO performance status 0-1
- Age ≥ 18 years
- Indication for treatment of the locoregional lymphatic drainage at the discretion of the treating physician allowed (not mandatory)
- Personally signed and dated written informed consent
Age in the registry: 18 years to - · Sex: Male · Does not accept healthy volunteers
This page is information, not medical advice. Discuss any trial with your doctor.