Ablative radiation with a focal boost for unfavorable prostate tumors

Single-Dose Image-Guided Radiotherapy (IGRT) With Focal Boost to the MRI-defined Macroscopic Tumor Volume for Intermediate Unfavorable and High Risk Prostate Cancer

This trial will test whether a single high-dose focal radiation or a five-fraction SBRT schedule is safe and tolerable for men with intermediate-unfavorable or selected high-risk localized prostate cancer.

Quick facts

• Study type: Observational
• Enrollment: 58 (estimated)
• Ages: 18 Years to 90 Years
• Sex: Male
• Sponsor: University of Milano Bicocca (other)
• Drugs / interventions: Radiation
• Locations: 1 site (Monza, MB)
• Trial ID: NCT07407608 on ClinicalTrials.gov

What this trial studies

ABRUPT 2.0 randomizes men with intermediate-unfavorable or selected high-risk organ-confined prostate cancer to either 24 Gy single-dose radiation therapy (SDRT) with a urethra-sparing focal boost or 36.25 Gy stereotactic body radiotherapy (SBRT) delivered in five fractions. The primary endpoint is acute genitourinary (GU) toxicity, with randomization balanced by risk group and conducted 1:1 at a single institution. All patients undergo same-day non-contrast CT and multiparametric MRI for planning, standardized bladder and rectal preparation, and image-guided volumetric arc therapy with strict planning and quality assurance. Androgen deprivation therapy is given per standard of care and staging requires N0M0 by conventional imaging or preferably PSMA PET-CT.

Who should consider this trial

Good fit: Ideal candidates are men with histologically proven prostate adenocarcinoma who have intermediate-unfavorable or selected high-risk, organ-confined (N0M0) disease, a PI-RADS 3–5 dominant lesion on mpMRI, ECOG 0–1, IPSS ≤15, prostate volume ≤100 g, and a life expectancy over 5 years.

Not a fit: Patients with ≥T3b disease, PSA >20 ng/mL, periurethral dominant lesions, prior pelvic radiotherapy or prior prostate surgery, active inflammatory bowel disease, or other excluded conditions are unlikely to benefit or are ineligible for this protocol.

Why it matters

Potential benefit: If successful, the single-dose approach could offer similar tumor control with far fewer clinic visits and acceptable urinary side effects.

How similar studies have performed: Published reports and phase II series indicate that single 24 Gy SDRT and multi‑fraction SBRT can achieve excellent local control with acceptable toxicity when strict planning constraints and image guidance are used, but randomized comparative data remain limited.

Eligibility criteria

Inclusion Criteria:

* Histologically proven prostate adenocarcinoma;
* Intermediate and High risk disease, as per the NCCN definition;
* a PI-RADS 3-5 dominant intraprostatic lesion on multiparametric MRI (mpMRI);
* N0M0 at staging with standard techniques (Bone Scan and Abdominal CT) or (preferably) PSMA PET-CT;
* World Health Organization performance status 0-1;
* Life expectancy of \> 5 years, in the opinion of the investigator;
* IPSS score must be ≤ 15 (alpha blockers allowed);
* Prostate gland volume ≤100 g as estimated by computed tomography (CT), ultrasound, or MRI.

Exclusion Criteria:

* ≥T3b disease according to the 8th AJCC classification;
* PSA\>20 ng/ml;
* Previous local treatment of the prostate with surgery (radical prostatectomy or cryotherapy) or transurethral resection;
* Previous radiotherapy to the pelvis;
* Presence of a periurethral dominant lesion;
* Previous invasive malignancy unless disease free for a minimum of 5 years;
* Active Crohn's Disease or Ulcerative Colitis;
* Presence of hip prostheses.

Where this trial is running

Monza, MB

• Radiation Oncology, Fondazione IRCCS San Gerardo dei Tintori — Monza, MB, Italy (RECRUITING)

Study contacts

• Study coordinator: Stefano Arcangeli, MD

Conditions: Prostate Cancer, Prostate Cancer Non-Metastatic, Unfavorable Prostate Tumors, Stereotactic Body Radiotherapy, Volumetric Modulated Arc Therapy, Prostate Imaging Reporting and Data System, Toxicity, Quality of Life