Adaptive radiotherapy for localized prostate cancer

Online Adaptive Stereotactic Body Radiotherapy for Localized Prostate Cancer in Patients With Lower Urinary Tract Symptoms and/or Prostate Hyperplasia (X-SMILE)

This study is testing a new type of radiation therapy for men with localized prostate cancer who have urinary problems to see if it can safely treat their cancer without causing too many side effects.

Quick facts

• Study type: Observational
• Enrollment: 75 (estimated)
• Ages: 18 Years and up
• Sex: Male
• Sponsor: University of Zurich (other)
• Locations: 3 sites (Heidelberg, Baden-Wurttemberg and 2 other locations)
• Trial ID: NCT06834152 on ClinicalTrials.gov

What this trial studies

This international multicenter study evaluates the safety, feasibility, and efficacy of online adaptive stereotactic body radiotherapy (SBRT) for patients with newly diagnosed localized prostate cancer who also experience lower urinary tract symptoms or prostatic hyperplasia. The treatment involves delivering SBRT in five weekly fractions, guided by either CT or MRI imaging. The primary goal is to assess the rate of urogenital toxicity within three months post-treatment, aiming to demonstrate that this rate remains below a clinically acceptable threshold. The study targets patients with intermediate to very high-risk localized prostate cancer, focusing on those with specific symptom scores and prostate volume criteria.

Who should consider this trial

Good fit: Ideal candidates include men with histologically confirmed localized prostate cancer, intermediate to very high-risk disease, and significant lower urinary tract symptoms or enlarged prostate.

Not a fit: Patients with low-risk localized prostate cancer or those without significant urinary symptoms or prostate enlargement may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could provide a safer and more effective treatment option for patients with localized prostate cancer who also have urinary symptoms.

How similar studies have performed: Previous studies have shown promising results with adaptive SBRT approaches, indicating potential for success in this novel application.

Eligibility criteria

Inclusion Criteria:

* histologically confirmed localized prostate cancer
* planned treatment is SBRT according to standard of care and consists of definitive CT or MRI online adaptive SBRT of the prostate according to the PACE trial which includes a total dose to clinical target volume 1 (CTV1, i.e. prostate and proximal 1 cm of the seminal vesicle) of 40.0 Gy in 5 weekly fractions (single dose of 8.0 Gy) and total dose to planning target volume 1 (PTV1) of 37.5 Gy in 5 weekly fractions (single dose of 7.5 Gy) with a compromise for bowel sparing allowed. For patients with unfavorable intermediate to very high-risk disease (according to NCCN guidelines) a total dose to the planning target volume 2 (PTV2, i.e. proximal 1-2 cm of the seminal vesicle) of 32.5 Gy in 5 weekly fractions (single dose of 6.5 Gy) will be delivered.
* intermediate to (very) high risk localized prostate cancer (≤ cT3a and Gleason score ≤ 9 and/or PSA ≤ 20 ng/ml)
* prostate volume \> 60 cc and/or IPSS \> 12;

Exclusion Criteria:

* Very high risk localized prostate cancer with indication for ADT and ARPI (i.e. Gleason ≥ 8 and cT3a)
* Involvement of seminal vesicles (cT3b)
* Contraindications against definitive CT or MRI-adaptive radiotherapy of the prostate, e.g. inflammatory bowel disease (IBD); previous radiotherapy in the pelvis, previous local radiotherapy of the prostate, contraindication for MRI or CT;
* Patients with severe genitourinary symptoms (e.g. recent urinary retention ≥ grade 3 according CTCAE v.5.0);
* Lymph node metastases or distant metastases (i.e. no localised prostate cancer);
* Participation in a clinical trial which might influence the results of this project.

Where this trial is running

Heidelberg, Baden-Wurttemberg and 2 other locations

• Klinik für Radioonkologie und Strahlentherapie, Universitätsklinikum Heidelberg — Heidelberg, Baden-Wurttemberg, Germany (NOT_YET_RECRUITING)
• Klinik und Poliklinik für Strahlentherapie und Radioonkologie, Universitätsklinikum LMU — Munich, Bavaria, Germany (NOT_YET_RECRUITING)
• University Hospital Zurich, Department of Radio-Oncology — Zurich, Canton of Zurich, Switzerland (RECRUITING)

Study contacts

• Principal investigator: Tiuri E. Kroese, MD, PhD — University of Zurich
• Study coordinator: Radiation Oncology Study Office

Conditions: Localized Prostate Carcinoma, Prostate Cancer, Prostate Hyperplasia, Lower Urinary Track Symptoms, radiotherapy, SBRT, MRI, CT