This interventional prospective multicenter international study will include 54 patients with very high-risk localized (cN0 cM0) or regional (i.e. cN1 cM0) prostate cancer according the NCCN criteria.
Patients will be treated with weekly CT or MR-informed online adaptive SBRT of the prostate and elective pelvic lymph nodes with 5 x 5 Gy. In the case of regional lymph nodes, a simultaneous integrated boost (SIB) of involved lymph nodes will be performed with 5 x 6.5 Gy. In the case of up to 2 dominant intraprostatic lesion (DIL) a SIB of the DIL with 5 x 9 Gy can be performed (optional). Importantly, coverage of these DIL volumes must be compromised as needed to respect OAR constraints.
This study is classified as risk category A according to ClinO, Art. 61, as stereotactic radiotherapy (SBRT) for localized or regional prostate cancer has been extensively evaluated in prospective interventional trials and is considered an established therapeutic modality.
Weekly CT- or MR-guided online adaptive SBRT to the prostate and elective pelvic lymph nodes with 5 × 5 Gy is, however, not yet routinely implemented for this specific patient population.
A diagnostic high field MRI during radiotherapy, e.g. week 3 is optional.
Follow-up is also according to standard of care (except for patient reported outcome measure using QLQ-C30 and QLQ-PR25 and a diagnostic MRI at 9 months after SBRT (optional), and 12 months in the case of an image non-complete response at 9 months (optional).
Who can participate
Age range
18 Years
Sex
MALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria include:
* Very high risk localized defined (cN0) according to NCCN guidelines consisting of ≥2 of the following:
* cT3 disease and/or
* Gleason 8-10 and/or
* PSA ≥40 (the baseline PSA value should be doubled for PSAs taken while on 5-alpha reductase inhibitors) OR
* Regionally metastatic prostate cancer (cN1, any T, any Gleason, any PSA) according to NCCN guidelines consisting of ≤3 lymph node metastases of any of the following:
* Obturator
* Internal iliac (hypogastric)
* External iliac nodes
* Presacral nodes
* Common iliac (below iliac bifurcation)
* Periprostatic/Perivesical AND
* Good to moderate performance status (WHO 0-2)
* Written informed consent.
* A PSMA PET and multiparametric MRI is mandatory according to staging guidelines.
* Age ≥ 18 years
Exclusion criteria include:
* ≥4 regional lymph nodes
* Patients with cT4 disease (tumor is fixed or invades adjacent structures other than seminal vesicles such as external sphincter, rectum, bladder, levator muscles, and/or pelvic wall)
* Previous RT to the pelvis or prostate
* Previous radical prostatectomy
* Large body size that would not fit into the MRI-simulator bore
* Presence of distant metastases (i.e. cM1)
* Non-regional lymph nodes (M1a):
* Common iliac
* Para-aortic / retroperitoneal
* Inguinal
* Mediastinal or supraclavicular
* Mesorectal
* Other
* Bone metastases (M1b)
* Other sites (M1c)
* Contraindications to CT or MR-adaptive SBRT (e.g., pacemake…
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Feasibility- a successful delivery of CT or MR-informed SBRT per fraction
Timeframe: from Day 1 of treatment up to 7 weeks until end of treatment
2
Safety - Adverse events
Timeframe: ≥ 3 months to within 1 year after completion of SBRT