The MR-Linac Technical Feasibility Protocol

Study Overview
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Brief Summary
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Radiation therapy is predominantly based on a Computed Tomography (CT) scan obtained during the treatment planning phase. During the course of radiotherapy, however, both the tumor and organs at risk (OAR) are variable in position, shape and size between fractions, and during beam delivery within one treatment fraction. Around the clinical target volume (CTV) a safety margin (Planning Target Volume, PTV) is created to account for these geometric uncertainties to ensure that the tumor receives the prescribed dose. Direct integration of imaging at the linear accelerator enables daily monitoring of patient positioning, tumor position, and alterations in patient anatomy. Image guided radiotherapy (IGRT) enables the detection and immediate correction of such deviations and increases the precision of delivery. Adaptive radiotherapy has become an important strategy for serially modifying dose distributions in a manner that can substantially reduce OAR dose and subsequent toxicity, while maintaining adequate target coverage. Current adaptive protocols rely upon a standard CT-based workflow and (cone-beam) CT-based image guidance. Magnetic Resonance Imaging (MRI) has superior soft-tissue contrast over CT and seems a very promising modality to integrate in the radiation treatment process, facilitating better visualization of the tumor and OAR during treatment.

Detailed Description
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The proposed protocol aims to determine feasibility of multiple new techniques and software for MR-guided adaptive radiation therapy. For each proposed technique feasibility has to be determined individually. A secondary aim is to prospectively collect data from cohorts of patients treated at the MRL and report on acute toxicity. By including multiple parallel cohorts, the protocol will accelerate the technical development of MR-guided adaptive radiotherapy and the evidence-based introduction of the MRL into clinical practice.

Official Title
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The MR-Linac Technical Feasibility Protocol For Development of MR-guided Adaptive RadiationTherapy

Conditions
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Tumors at All Sites Which Will Receive Radiotherapy

Intervention / Treatment
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* Radiation: radiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient, age ≥ 18 years, treated with radiation therapy on the MRL. WHO performance 0-2. Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: Contra-indications for an MRI examination. Patient is pregnant. Claustrophobia. Patients >140 kg and/or a body width > 60 cm. Patients with any other clinically significant medical condition which, in the opinion of the treating physician, makes it undesirable for the patient to participate in the study or which could jeopardize compliance with study requirements or severe psychiatric illness/social situation.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: MRL<br>radiotherapy on MR linac | Radiation: radiotherapy<br>* multiple new techniques and software for MR-guided adaptive radiation therapy.<br>* Other names: MR Linac;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| technical feasibility | Feasibility of the technical procedure is demonstrated if the technique is successfully applied in 9 out of 10 consecutive patients | 4 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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radiotherapy, MR Linac