Single-dose 24 Gy radiotherapy for localized low- and intermediate‑risk prostate cancer

Feasibility Trial of Single-Dose Radiotherapy for Localized Low and Intermediate Risk Prostate Cancer Using Special System of Internal and External Immobilization for Target Motion Mitigation

This trial will try a single 24 Gy high‑dose radiotherapy using internal and external immobilization to see if it can be delivered precisely and safely for men with localized low‑ or intermediate‑risk prostate cancer.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 18 Years and up
• Sex: Male
• Sponsor: Branch Office of "Hadassah Medical Ltd" (other)
• Drugs / interventions: radiation
• Locations: 1 site (Moscow)
• Trial ID: NCT07112781 on ClinicalTrials.gov

What this trial studies

The trial delivers a single 24 Gy fraction of external‑beam radiotherapy using VMAT with image guidance and a dedicated internal (air‑filled endorectal balloon and Foley catheter) and external patient immobilization system to hold the prostate steady. Treatment planning uses volumetric intensity‑modulated arc therapy with state‑of‑the‑art dosimetry and quality assurance to minimize dose to normal tissues. Eligible patients are men with biopsy‑proven localized prostate adenocarcinoma classified as low or intermediate risk by NCCN criteria, with prostate volume ≤100 cc and limited urinary symptoms. The study will record technical delivery parameters, normal‑tissue dose metrics, acute and late adverse events, and biochemical control outcomes over follow‑up.

Who should consider this trial

Good fit: Men aged 18 or older with biopsy‑confirmed localized prostate adenocarcinoma classified as low or intermediate risk (T1–T2c, PSA ≤20 ng/mL, Gleason ≤7), prostate volume ≤100 cc, IPSS ≤15, performance status 0–2, and no regional or distant metastases are ideal candidates.

Not a fit: Patients with high‑risk features (T3–T4, Gleason >7), positive lymph nodes or metastatic disease, very large prostates (>100 cc), or significant urinary symptoms (IPSS >15) are unlikely to be eligible or to benefit from this approach.

Why it matters

Potential benefit: If successful, this could provide a one‑time, highly convenient treatment option with similar tumor control and low severe toxicity compared with multi‑fraction regimens.

How similar studies have performed: Randomized and nonrandomized work including the PROSINT trial and multiple SBRT series have shown comparable biochemical control and low rates of severe toxicity for ultra‑hypofractionation, and early PROSINT 4‑year results suggest single‑dose 24 Gy can be delivered with favorable safety profiles though longer follow‑up is limited.

Eligibility criteria

Inclusion Criteria:

* Signed study specific informed consent form;
* Histologic confirmation of adenocarcinoma of the prostate by biopsy;
* Biopsy Gleason score ≤ 7;
* Up to 6 months of previous hormonal therapy is allowed (but not required);
* PSA ≤ 20 prior to hormone therapy (if given);
* No direct evidence of regional or distant metastases after appropriate staging studies (CT, MRI, 68Ga-Prostate-Specific Membrane Antigen (PSMA) Positron emission tomography (PET) / CT)
* Age ≥ 18;
* Performance Status 0-2;
* International Prostate Symptom Score (IPSS) must be ≤ 15 (alpha blockers allowed)
* Computerized Tomography (CT) or Magnetic Resonance Imaging (MRI) or Ultrasound-based volume estimation of prostate gland ≤ 100 cc

Exclusion Criteria:

* Positive lymph nodes or metastatic disease from prostate cancer on imaging studies (CT, MRI, 68Ga-Prostate-Specific Membrane Antigen (PSMA) Positron emission tomography (PET) / CT);
* Tumour Clinical stage T3 or T4 on MRI;
* Gleason score \> 7;
* PSA \> 20 ng/mL;
* Previous pelvic radiotherapy;
* Previous surgery for prostate cancer;
* Recent transurethral resection of the prostate (TURP) (less than 3 months);
* Previous hormonal therapy given for more than 6 months prior to therapy;
* Prior invasive malignancy unless disease free for a minimum of 3 years;
* Previous significant urinary obstructive symptoms;
* Significant psychiatric illness;
* Ultrasound or CT or MRI estimate of prostate volume \> 100 cc;
* Severe, active co-morbidity.
* Inability to fulfill all dosimetric criteria for target dose coverage and restrictions for the organs at risk according to study protocol;

Where this trial is running

Moscow

• The Branch of Hadassah Medical LTD — Moscow, Russia (RECRUITING)

Study contacts

• Principal investigator: Sergey Usychkin, MD — Chief Radiation Oncologist
• Study coordinator: Sergey Usychkin, MD

Conditions: Prostate Cancer, Radiotherapy