Online Adaptive Stereotactic Body Radiotherapy for Localized Prostate Cancer (X-SMILE)

NCT ID: NCT06834152

Last Updated: 2025-02-19

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 30 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-03-01
• Study Completion Date: 2031-06-01

Brief Summary

The aim of this phase II international multicenter study is to evaluate the safety, feasibility, and efficacy of CT or MRI-adaptive SBRT, delivered in five weekly fractions, in patients with newly diagnosed localized prostate cancer who have lower urinary tract symptoms and/or prostatic hyperplasia.

Detailed Description

Background: Stereotactic body radiotherapy (SBRT) for localized prostate cancer has demonstrated non-inferior oncological outcomes and toxicity profiles to conventionally or moderately hypofractioned radiotherapy regimens, while offering the advantage of shorter treatment durations. However, SBRT may not be suitable for all patients, particularly those with lower urogenital tract symptoms and/or prostatic hyperplasia.

Methods: This study aims to evaluate the safety and efficacy of weekly computed tomography (CT) or magnetic resonance image-guided (MRI) online adaptive SBRT in patients with intermediate to (very) high-risk localized prostate cancer who present with lower urinary tract symptoms (International Prostate Symptom Score [IPSS] > 12) and/or have prostate hyperplasia (prostate volume >60 mL). The primary outcome measure is urogenital toxicity grade ≥3 within 3 months after completion of SBRT (according to CTCAE V5.0 and RTOG) or discontinuation of therapy. Our aim is to show that the event rate is at 3% below a clinically acceptable threshold, which is set at 20%. Under the null hypothesis, this design with an alpha of 0.05 and power of 80% results in an expected number of cases of 30.

Conditions

Localized Prostate Carcinoma; Prostate Cancer (Adenocarcinoma); Prostate Hyperplasia; Lower Urinary Track Symptoms

Study Design

• Observational Model Type: CASE_ONLY
• Study Time Perspective: PROSPECTIVE

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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: No

Sponsors

University of Zurich

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Matthias Guckenberger, Prof. Dr. med.

Role: STUDY_CHAIR

University of Zurich

Tiuri E. Kroese, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Zurich

Michael Mayinger, PD Dr. med.

Role: PRINCIPAL_INVESTIGATOR

University of Zurich

Locations

Klinik für Radioonkologie und Strahlentherapie, Universitätsklinikum Heidelberg

Heidelberg, Baden-Wurttemberg, Germany

Site Status: NOT_YET_RECRUITING

Klinik und Poliklinik für Strahlentherapie und Radioonkologie, Universitätsklinikum LMU

Munich, Bavaria, Germany

Site Status: NOT_YET_RECRUITING

University Hospital Zurich, Department of Radio-Oncology

Zurich, Canton of Zurich, Switzerland

Site Status: RECRUITING

Countries

Germany; Switzerland

Central Contacts

Radiation Oncology Study Office

Role: CONTACT

RAO_akademischesoffice@usz.ch

+41442554108

Facility Contacts

Jürgen Debus, Prof. Dr. med. Dr. rer. nat.

Role: primary

juergen.debus@med.uni-heidelberg.de

Claus Belka, Prof. Dr. med.

Role: primary

Claus.Belka@med.uni-muenchen.de

Matthias Guckenberger, Prof. Dr. med.

Role: primary

matthias.guckenberger@usz.ch

+41 44 255 31 50

References

Kroese T, Andratschke N, Belka C, Corradini S, Marschner S, Liermann J, Horner-Rieber J, Fink C, Debus J, Silvia F, Tanadini-Lang S, Pouymayou B, Mencarelli A, Fesslmeier D, Schiess A, Guckenberger M, Mayinger M. Online adaptive stereotactic body radiotherapy for localized prostate cancer in patients with lower urinary tract symptoms and/or prostate hyperplasia (X-SMILE). Radiat Oncol. 2025 May 28;20(1):90. doi: 10.1186/s13014-025-02653-4.

Reference Type: DERIVED

PMID: 40437508 (View on PubMed)

Other Identifiers

RAO-24-014

Identifier Type: -

Identifier Source: org_study_id