Single-dose radiation therapy for prostate cancer

ONE-SHOT - Single Shot Radiotherapy for Localized Prostate Cancer. A Multicenter, Single Arm, Phase I/II Trial

Phase1; Phase2 Interventional University Hospital, Geneva · NCT03294889

This study is testing if a single high-dose radiation treatment can safely and effectively help men with localized prostate cancer while causing less harm to healthy tissue.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment45 (estimated)
Ages18 Years to 85 Years
SexMale
SponsorUniversity Hospital, Geneva Academic / other
Locations1 site (Geneva)
Trial IDNCT03294889 on ClinicalTrials.gov

What this trial studies

This trial aims to evaluate the safety and effectiveness of a single high-dose stereotactic body radiation therapy (SBRT) of 19 Gy in patients with localized prostate cancer. The study will utilize advanced image-guided radiation techniques to potentially enhance tumor control while minimizing damage to surrounding healthy tissues. By exploring ultra-hypofractionation, the trial seeks to determine if fewer treatment sessions can achieve similar or better outcomes compared to traditional radiation schedules. The trial is designed as a phase I/II study to gather preliminary data before a larger phase III trial.

Who should consider this trial

Good fit: Ideal candidates include men with localized prostate cancer, specifically those with a Gleason score of 3+3 or 3+4 and a PSA level of 15 ng/ml or lower.

Not a fit: Patients with advanced prostate cancer (clinical stage cT3 or higher) or those with metastatic disease will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could provide a more effective and less time-consuming treatment option for patients with localized prostate cancer.

How similar studies have performed: Other studies have shown promising results with hypofractionated radiation therapy, suggesting that this approach may be effective, though this specific single-dose method is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Written informed consent according to ICH/GCP regulations before registration and prior to any trial specific procedures
* Histologically confirmed adenocarcinoma of the prostate without small cell features
* Tumor clinical stage cT1c-2c, pN0 or cN0, M0, according to UICC TNM 2009
* MRI staging must confirm American Joint Committee on Cancer (AJCC) stage T1, T2a, T2b or T2c
* Gleason score at biopsy 3+3 or 3+4 (WHO 2016 Grade Groups 1, 2)
* PSA ≤15 ng/ml
* WHO performance status 0-1
* International Prostate Symptom Score ≤ 10 (alpha blockers allowed)
* MRI-based volume estimation of prostate gland ≤ 70 cc
* Patient agrees not to father a child during trial treatment and during 6 months thereafter

Exclusion Criteria:

* Tumor clinical stage cT3a-3b or T4
* Evidence of T3a, T3b or T4 disease as assessed by MRI
* Positive lymph-nodes or metastatic disease from prostate cancer on imaging studies.
* Significant tumor on the transitional zone as assessed by MRI
* Gleason at biopsy ≥ 4+3
* Androgen deprivation therapy or products known to affect PSA levels
* Impossibility to implant Calypso beacons
* History of hematologic or primary solid tumor malignancy, unless in remission for at least 3 years from registration with the exception of curatively treated localized non-melanoma skin cancer
* Prior pelvic radiotherapy
* Previous surgery for prostate cancer
* Previous transurethral resection of the prostate (TURP) (\< 12 weeks before registration)
* Hip prosthesis
* Severe or active co-morbidity likely to impact on the advisability of SBRT
* Any other serious underlying medical, psychiatric, psychological, familial or geographical condition, which in the judgment of the investigator may interfere with the planned staging, treatment and follow-up, affect patient compliance or place the patient at high risk from treatment-related complications

Where this trial is running

Geneva

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Prostate CancerProstate cancerStereotactic body radiation therapyCalypso® beacon system
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.