A Phase 2 interventional study of Next generation Stereotactic Ablative Radiotherapy (SABR) in Prostate Adenocarcinoma, sponsored by Cancer Trials Ireland. Recruiting at 4 sites in 2 countries. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-06.
Sponsored by Cancer Trials Ireland · Phase 2, Interventional, and Treatment
This is a Phase II, single arm, multi-centre, prospective clinical trial evaluating next generation Stereotactic Ablative Radiotherapy (SABR) for low, intermediate, and eligible high-risk prostate cancer. Eligible patients will receive next generation prostate SABR incorporating toxicity reduction strategies
This is a Phase II, single arm, multi-centre, prospective clinical trial evaluating next generation Stereotactic Ablative Radiotherapy (SABR) for low, intermediate, and eligible high-risk prostate cancer. Eligible patients will receive next generation prostate SABR incorporating toxicity reduction strategies: urethral/trigone sparing, rectal hydrogel spacer, and neurovascular bundle preservation [as per Desai POTEN-C trial, Desai et al., 2025].
Treatment will prioritise the dominant intraprostatic lesion (DIL) while sparing surrounding organs at risk (OARs). Planned doses are: DIL 40-50 Gy in 5 fractions delivered on alternate days, prostate CTV 35 Gy, PTV 33.25 Gy, and urethral PRV 32.5 Gy. Eligible high-risk and some intermediate-risk patients may receive 6-12 months of androgen deprivation therapy (ADT)/hormonal therapy at the physician's discretion, provided they have not received >14 weeks prior to registration.
Radiotherapy planning will include advanced image-guided verification with fiducial markers, pre-treatment dosimetry to minimise dose to OARs, and adherence to protocol-defined constraints for urethra, rectum, and neurovascular bundles. Peri-rectal spacers will be inserted 7-10 days prior to CT-simulation to reduce rectal dose. Dose prioritisation allows full coverage of the DIL while sparing urethra, bladder trigone, and neurovascular bundles to minimise genitourinary, rectal, and sexual toxicity.
Follow-up assessments will include clinical evaluation, toxicity reporting using v5 NCI CTCAE, and patient-reported outcome measures (PRO/QoL) at 2-, 4-, 8-, and 12-weeks post-treatment, 6 and 9 months, and annually up to 5 years. Data on biochemical/clinical failure, progression-free survival, and initiation or re-initiation of ADT will also be collected.
A total of 136 patients will be enrolled to achieve 122 evaluable participants, allowing detection of a statistically significant reduction in Grade ≥2 late genitourinary toxicity compared to historical SABR controls.
7,046 studies on the registry are indexed under Prostatic Neoplasms; 1,580 are open to participants now.
This study's planned enrollment of 136 is above the median of 60 across 5,348 interventional studies indexed under Prostatic Neoplasms.
Browse Prostatic Neoplasms studies →Cancer Trials Ireland is the lead sponsor of 71 studies on the registry; 8 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients belonging to one of the following risk groups:
Low risk - patients meeting all of the following criteria:
Intermediate risk - patients meeting any of the following criteria, assuming no high-risk features apply:
High risk - patients with tumours that meet a maximum of one of the following criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Eligible patients will receive next generation prostate SABR incorporating toxicity reduction strategies: urethral/trigone sparing, rectal hydrogel spacer, and neurovascular bundle preservation.
Radiation: Next generation Stereotactic Ablative Radiotherapy (SABR)
Treatment will prioritise the dominant intraprostatic lesion (DIL) while sparing surrounding organs at risk (OARs).
Late GU toxicity
Rate of ≥ Grade 2 version 5 (v5) NCI CTCAE late GU toxicity in next-generation prostate SABR at 2 years.
Time frame: 2 years after last fraction
Acute GU Toxicity
Acute Grade ≥ 2 GU toxicity ≤12 weeks, using v5 NCI CTCAE
Time frame: ≤12 weeks after last fraction
Acute GI Toxicity
Acute Grade ≥ 2 GI toxicity ≤12 weeks, using v5 NCI CTCAE
Time frame: ≤12 weeks after last fraction
Late GU toxicity at 5 years
Late Grade ≥ 2 GU toxicity at 5 years, using v5 NCI CTCAE
Time frame: 5 years after last fraction
Late GI toxicity at 5 years
Late Grade ≥ 2 GI toxicity at 5 years, using v5 NCI CTCAE
Time frame: 5 years after last fraction
Patient-Reported Outcomes (PRO) / Quality of Life (QoL) assessments for all patients via Expanded Prostate Cancer Index Composite Short Form (EPIC-26).
EPIC-26 will be reported at 4 weeks, 12 weeks, 6, 9, and 12 months following treatment and yearly thereafter (until year 5). Response options for each EPIC item form a Likert scale, and multi- scores are transformed linearly to a 0-100 scale with higher scores representing better HRQOL.
Time frame: 4 weeks, 12 weeks, 6, 9, and 12 months, 24 months, 36 months, 48 months, 60 months after treatment
Patient-Reported Outcomes (PRO) / Quality of Life (QoL) assessments for all patients via International Index of Erectile Function (IIEF-5).
IIEF-5 will be reported at 12 weeks, 6 and 12 months following treatment and yearly thereafter (until year 5). IIEF-5 is reported on a scale of 5 to 25 with higher scores representing better function.
Time frame: 12 weeks, 6 and 12 months, 24 months, 36 months, 48 months, 60 months after treatment
Patient-Reported Outcomes (PRO) / Quality of Life (QoL) assessments for all patients via International Prostate Symptom Score (IPSS).
IPSS will be reported at 4 weeks, 12 weeks, 6, 9, and 12 months following treatment and yearly thereafter (until year 5). The total symptom score of IPSS ranges from 0 to 35 where 0 indicates no symptoms and 35 indicates the patient is severely symptomatic.
Time frame: 4 weeks, 12 weeks, 6, 9, and 12 months, 24 months, 36 months, 48 months, 60 months after treatment
Freedom from biochemical or clinical failure.
Freedom from biochemical (Phoenix definition) or clinical (commencement or re-commencement of androgen deprivation therapy \>12 weeks after completing the neoadjuvant/adjuvant course of ADT, local recurrence, nodal recurrence and distant metastases) failure.
Time frame: The primary timepoint of interest is 5 years from registration.
Disease specific survival and overall survival
Disease specific survival and overall survival
Time frame: 5 years from registration.
Progression-free survival (PFS)
Progression-free survival (PFS) - radiographic, clinical or biochemical evidence of local or distant failure.
Time frame: 5 years from registration
To assess commencement or re-commencement of androgen deprivation therapy (ADT)
Eligible high-risk patients and some intermediate risk patients may be planned to receive (or may have already commenced) 6-12 months ADT/hormonal therapy at physician's discretion.
Time frame: Up to five years post last fraction.
Patient-Reported Outcomes (PRO) / Quality of Life (QoL) assessments for all patients via Penile Shortening and well being questionnaire (PSW E9).
PSW E9 will be reported at baseline, 6 months and 2 years post treatment. PSW E9 is a 9 item questionnaire using a Likert scale 0-4 where higher scores indicate lower satisfaction.
Time frame: Baseline, 6 months and 2 years post treatment.
Plan to share: Undecided
No publications or documents are linked to this record.
Started Apr 2026 (actual). Primary completion is estimated for Sep 2030, 53 months after the start.
Of 610 non-industry phase 2 interventional studies under Prostatic Neoplasms, half reached primary completion within 57 months of starting (the median), counting those still running; a quarter within 39 and three quarters within 86. This study's planned 53 months is close to that.
Counting every sponsor, half of 724 studies reached it within 53 months; a quarter within 34 and three quarters within 80.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Cancer Trials Ireland