Recruiting NCT07552168

INSPIRE: INnovative SABR for Prostate Cancer All IREland

Phase II Interventional Prostate Adenocarcinoma

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied: The protocol lists: Next generation Stereotactic Ablative Radiotherapy (SABR).
Who it may be relevant to: Registry conditions: Prostate Adenocarcinoma. Basic parameters: from 18 years · Male.
What needs checking: Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place: Ireland, United Kingdom
Next step: Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Overview

Detailed description

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.

Interventions

Radiation Next generation Stereotactic Ablative Radiotherapy (SABR)
Treatment will prioritise the dominant intraprostatic lesion (DIL) while sparing surrounding organs at risk (OARs).

Primary outcome measures

Late GU toxicity [Time frame: 2 years after last fraction]

Secondary outcome measures (11)

Acute GU Toxicity [Time frame: ≤12 weeks after last fraction]
Acute GI Toxicity [Time frame: ≤12 weeks after last fraction]
Late GU toxicity at 5 years [Time frame: 5 years after last fraction]
Late GI toxicity at 5 years [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). [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). [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). [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. [Time frame: The primary timepoint of interest is 5 years from registration.]
Disease specific survival and overall survival [Time frame: 5 years from registration.]
Progression-free survival (PFS) [Time frame: 5 years from registration]
To assess commencement or re-commencement of androgen deprivation therapy (ADT) [Time frame: Up to five years post last fraction.]

Eligibility criteria

Inclusion criteria

Written informed consent obtained prior to any study-related procedures
Males ≥ 18 years of age
ECOG performance status (PS) 0-2
Biopsy-proven prostate adenocarcinoma without neuro-endocrine differentiation (within 18 months prior to registration, unless on active surveillance and re-biopsy not clinically indicated)
Gleason score ≤ 4+3
Clinical and/or MRI stage T1c-T3a, N0-X, M0-X
PSA ≤ 30 ng/ml (within 60 days prior to registration / prior to starting androgen-deprivation therapy (ADT/hormone therapy) \[PSA ≤ 15 ng/ml for patients on 5-alpha reductase inhibitors\]
Patients belonging to one of the following risk groups:

Low risk - patients meeting all of the following criteria:

Gleason ≤ 6
Clinical stage T1c-T2a
PSA < 10 ng/ml (within 60 days prior to registration)
Intermediate risk - patients meeting any of the following criteria, assuming no high-risk features apply:

Gleason 7 (3+4 or 4+3)
MRI stage T2b-T2c (N0, M0-X)
PSA 10-20 ng/ml (within 60 days prior to registration)
High risk - patients with tumours that meet a maximum of one of the following criteria:

MRI stage T3a (N0, M0)
PSA >20 - ≤30 ng/ml (within 60 days prior to registration)

Exclusion criteria

Previous malignancy within the last 2 years (except basal cell carcinoma (BCC) or squamous carcinoma of the skin), or if previous malignancy is expected to significantly compromise 5 year survival
Prior pelvic radiotherapy
Any prior active treatment for prostate cancer (with the exception of ADT). Patients previously on active surveillance are eligible if they continue to meet all other eligibility criteria.
Life expectancy <5 years.
Bilateral hip prostheses or any other implants/hardware that would introduce substantial CT artefacts
Medical conditions likely to make radiotherapy inadvisable e.g. inflammatory bowel disease, significant urinary symptoms.
Anticoagulation with warfarin/bleeding tendency making fiducial placement or surgery unsafe in the opinion of the clinician. Note: Anti-platelet agents e.g. aspirin, clopidogrel and DOACs such as apixaban, rivaroxaban are not contraindications to trial entry.
Participation in another concurrent treatment protocol for prostate cancer (not including QoL, survivorship, exercise or registry studies).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation: N/A
Model: Single group
Masking: Open label
Primary purpose: Treatment

Study locations

Ireland · 3 centers

St Luke's Centre for Radiation Oncology at Beaumont Hospital — Dublin
Bon Secours - UPMC Hillman — Cork
UPMC Hillman Cancer Centre at Whitfield Hospital — Waterford

United Kingdom · 1 center

Northern Ireland Cancer Centre (NICC) — Belfast

Identifiers

NCT: NCT07552168 · CTRIAL-IE 24-72

Primary sources (government registries)

ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗