Magnetic Resonance Imaging-guided Online Adaptive Radiotherapy of Pelvic Lymph Node Metastases

NCT ID: NCT07083648

Last Updated: 2025-07-24

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-07-16
• Study Completion Date: 2028-07-31

Brief Summary

In this study, the investigators want to investigate whether online-adapted radiotherapy using a special magnetic resonance imaging (MRI) simulator and computed tomography (CT)-guided radiation therapy, is feasible and offers advantages for the treatment of pelvic lymph node metastases.

Detailed Description

MR-guided online adaptive radiotherapy has been implemented recently using MR-linac technology, where MR-imaging is combined with linac technology in hybrid systems. These systems offer MR imaging for online adaptive radiotherapy (RT) within the treatment room and with the patient in treatment position. Despite results regarding technical and clinical feasibility being promising, the high costs of MR-linacs systems and the high demands for staffing resources of MR-linacs are limiting a boarder implementation of this technology. At the Department of Radiation Oncology, University Hospital Zurich, MRI-simulations for RT planning using a dedicated scanner have been performed since 2023. The investigators have developed and implemented an MRI-only RT planning workflow followed by RT delivered at a CBCT-guided, conventional linac. The aim to expand the MRI-only workflow to online adaptive RT. This study will investigate the feasibility of MRI-guided, online adaptive SBRT for pelvic and para-aortic lymph node metastases using a dedicated MR simulator and treatment delivery using conventional CBCT-linac technology.

Conditions

Pelvic and Para-aortic Lymph Node Metastases

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

MR-guided online adaptive RT using a dedicated MR-simulator and cone-beam CT (CBCT)-based treatment

Group Type: EXPERIMENTAL

Magnetic resonance Imaging-guided online adaptive radiotherapy

Intervention Type: RADIATION

On each day of treatment, a new MRI scan in the treatment position will be acquired using the dedicated MR simulator, co-registered with the original one. The original target and organ at risk (OAR) contours will be propagated to the new image set using rigid and deformable image registration. The contours will be adapted to changes detected with MRI of the day. The original SBRT treatment plan will be adapted to the changed and hence adapted anatomy of targets and OARs by plan optimization. Dose calculation will be performed on the newly generated synthetic CT (preferred) or, if there is a contra-indication for synthetic CT, on the original image.

Interventions

Magnetic resonance Imaging-guided online adaptive radiotherapy

On each day of treatment, a new MRI scan in the treatment position will be acquired using the dedicated MR simulator, co-registered with the original one. The original target and organ at risk (OAR) contours will be propagated to the new image set using rigid and deformable image registration. The contours will be adapted to changes detected with MRI of the day. The original SBRT treatment plan will be adapted to the changed and hence adapted anatomy of targets and OARs by plan optimization. Dose calculation will be performed on the newly generated synthetic CT (preferred) or, if there is a contra-indication for synthetic CT, on the original image.

Intervention Type: RADIATION

Eligibility Criteria

Inclusion Criteria

• Intra-pelvic and para-aortic lymph node metastases from a histologically confirmed malignancy;
• Indication for SBRT based on a multidisciplinary tumor board recommendation and / or clinical practice guideline;
• Intra-pelvic and para-aortic lymph node metastases confirmed by imaging and amenable for SBRT

Exclusion Criteria

• Large body size that would not fit the MRI-simulator bore;
• Contraindications for MRI including but not limited to

• electronic devices such as pacemakers, defibrillators, deep brain stimulators, cochlear implants that are labeled as MR unsafe. Electronic devices labeled as MR safe or MR conditional are not a contraindication;
• metallic foreign body in the eye or aneurysm clips in the brain;
• severe claustrophobia;
• hip prosthesis that are labeled as MR unsafe;
• More than 5 pelvic lymph node metastasis
• Previous radiation therapy directly overlapping with SBRT in this study and leading to exceeding tolerance of OARs;
• History of Crohn's disease, ulcerative colitis

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

Sponsors

University of Zurich

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Zurich University Hospital, Department of Radiation Oncology

Zurich, Canton of Zurich, Switzerland

Site Status: RECRUITING

Countries

Switzerland

Central Contacts

Sebastian Christ, MD

Role: CONTACT

Sebastian.Christ@usz.ch

+41 43 253 07 17

Facility Contacts

Sebastian Christ

Role: primary

sebastian.christ@usz.ch

+41 44 255 35 66

Other Identifiers

RAO-24-017

Identifier Type: -

Identifier Source: org_study_id