Adaptive MR-guided SBRT for Localized Prostate Cancer

Not Applicable

Not yet recruiting

• Conditions: Prostate Cancer
• Interventions: Radiation: Stereotactic Body Radiation Therapy (SBRT)

• Registration Number: NCT04571762
• Lead Sponsor: University of Zurich

Brief Summary

The purpose of this study is to evaluate a technical feasibility of MR-guided SBRT fraction dose adaptation for low-risk, intermediate-risk and low-volume metastatic prostate cancer. .

Detailed Description

Hypofractionated SBRT to 36.25 Gy in 5 fractions (fraction dose 7.25 Gy) for low- and intermediate risk prostate cancer is standard of care. Using higher fraction doses that might be beneficial for disease control is not safe in all patients, unless adaptive treatment is performed. In this clinical trial the feasibility of online MR-guided SBRT fraction dose adaptation (between 7 and 8 Gy) for prostate cancer will be investigated. A fraction dose to the planning target volume (PTV) will be adapted to organs-at-risk (OAR) geometry (position, shape and volume) on online planning MRI scans of the treatment day ("geometry-of-the-day"). Thus the investigators hope to maximize treatment individualization.

Study Timeline

• Study First Submitted: 2020-07-09
• Study First Submitted QC: 2020-09-25
• Study First Posted: 2020-10-01
• Status Verified: 2024-05
• Last Update Submitted: 2024-05-22
• Last Update Posted: 2024-05-23
• Study Start: 2024-09-30
• Primary Completion: 2025-09-30
• Study Completion: 2026-05-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Male
• Target Recruitment: 12

Inclusion Criteria

• Written informed consent according to Swiss law and ICH/GCP regulations before any trial specific procedures;
• Males;
• Histologically confirmed adenocarcinoma of the prostate;
• Low (Grade group 1 [Gleason score ≤6], clinical stage T1-2a N0 M0, and PSA < 10 ng/ml) and intermediate (Grade group 2-3 [Gleason score 7], clinical stage T2b-2c N0 M0, PSA 10-20 ng/ml) risk prostate cancer with indications for SBRT with curative intent;
• Newly diagnosed low-volume metastatic prostate cancer with indications for SBRT, in whom metastatic disease was confirmed on a bone scintigraphic scan and soft-tissue imaging done within 3 months of starting androgen deprivation therapy (ADT);
• IPSS <15;
• Age: ≥ 18 years old;
• Karnofsky performance status ≥70;
• Patients able to tolerate long (approximately 60 minutes) treatment time;
• Patients who are willing and able to comply with scheduled visits, treatment, and other trial procedures.

Exclusion Criteria

• Previous radical treatment for prostate cancer - either radiation therapy (external or brachytherapy), surgery, TUR-P, cryosurgery, or HIFU;
• Contraindications for MRI, e.g., patients with metal fragments or implanted devices that are not MR compatible such as certain types of pacemakers and aneurysm clips or severe claustrophobia;
• Lack of safe contraception;
• Known or suspected non-compliance, drug or alcohol abuse;
• Inability to follow the procedures of the trial, e.g. due to language problems of the participant;
• Enrolment of the investigator, his/her family members, employees and other dependent persons.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Single arm	Stereotactic Body Radiation Therapy (SBRT)	Patients with low-risk, intermediate-risk and low-volume metastatic prostate cancer eligible for stereotactic body radiotherapy will be recruited.

Primary Outcome Measures

Name	Time	Method
Feasibility of online MR-guided SBRT: Number of fractions	At the treatment end (treatment duration 2 weeks)	Number of fractions when a new online plan on the new patient geometry was successfully generated and applied according to the dosimetric protocol requirements

Secondary Outcome Measures

Name	Time	Method
Quantifying intrafraction motion of the prostate (in mm) and organs-at-risk (in mm)	During each treatment session (treatment duration of 2 weeks)	Changes in the organ motion (in mm) during a treatment session
Quality of the adapted treatment plan vs. the initial treatment plan	At the treatment end (treatment duration 2 weeks)	Comparison of radiation doses delivered to the targets and organs-at-risk with the adapted treatment plan vs. the initial treatment plan
Rates of adverse events	weekly during treatment and up to 3 months after the treatment end	Adverse and severe adverse events measured with Common Terminology Criteria for Adverse Events (CTCAE) (version 5.0)
Quantifying interfraction motion of the prostate (in mm) and organs-at-risk (in mm)	Before each treatment session (treatment duration of 2 weeks)	Changes in the organ (the prostate and organs-at-risk \[in mm\]) motion between treatment sessions
Duration of an online adaptive procedure	Before each treatment session (treatment duration 2 weeks)	Time needed for adapting a treatment plan