Feasibility of MRI Workflow Alone in External Radiotherapy for the Treatment of Brain and Prostate Tumors (PRIS)

In radiotherapy, Magnetic Resonance Imaging (MRI) is used as a complement to the CT scanner because it provides better tissue contrast and therefore more precise delineations without the need for additional irradiation. However, MRI does not allow the definition of the electronic densities of the tissues necessary for dose calculation.

In this work, we sought to measure the feasibility of a method for generating CT-synthetic images from MRI in terms of dosimetric and geometrical precision for the purpose of MRI workflow alone (see diagram). The cerebral sphere and the prostate are the two tumor locations considered. All patients will have a planning CT (reference) and an MRI in the treatment position. The contours of the structures will be contoured by a radiotherapist on both the MRI and the reference CT. Synthetic CTs will be generated from the MRI with the method of automatic assignment of densities in five classes. The volumes bypassed and the dosimetries performed will be compared. A study of the quality of the images generated from MRI for dose calculation and images for the verification of per-treatment positioning will be performed.

Study Overview

• Status: Completed
• Conditions: Prostate Cancer; Brain Cancer
• Intervention / Treatment: Diagnostic test: Synthetic CT Scan

Detailed Description

This is a prospective single-center dosimetry study that exhaustively included brain tumor and prostate cancer patients treated at the ICO Site d'Angers by external radiotherapy and prior to which they were given an MRI and a simulation CT in treatment position over a 12-month period.

For patients who agree to participate in the study, CT-synthetic images will be generated from the MRI images by automatic assignment of densities (5 classes).

Reference CT images from CT and synthetic CT images from MRI will be available for comparison for all eligible patients.

• Study Type: Observational
• Enrollment (Actual): 94

Contacts and Locations

Study Locations

• France
  • Angers, France, 49055
    • Institut de Cancerologie de L'Ouest

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patient with prostate or brain cancer receiving an MRI in addition to the simulated CT scan prior to the start of their external radiotherapy treatment

Description

Inclusion Criteria:

1. Age ≥ 18 years old
2. Male or Female with a (primary) brain tumour or Male with cancer and localized (non-metastatic) prostate cancer
3. Patient having benefited from a planning MRI scan in treatment position performed according to the new acquisition modalities (allowing the generation of CT-synthetics by automatic assignment of densities) performed since January 2020 and a planning scanner in treatment position prior to external radiotherapy.
4. Good general condition (SP < 3)

Exclusion Criteria:

1. Excluded forms of the disease,
2. MRI-specific contraindications (claustrophobia, foreign bodies)
3. Obesity preventing the placement of equipment (contention/antennae)
4. Poor general condition (SP > or = 2) preventing the patient from standing on the table -

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Prostate cancer; Man with cancer and localized (non-metastatic) prostate cancer	Diagnostic test: Synthetic CT Scan; method of generating CT-synthetic image from MRI
Brain cancer; Male or Female with a brain tumor (primitive)	Diagnostic test: Synthetic CT Scan; method of generating CT-synthetic image from MRI

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
describe the differences in volumetric and dosimetric accuracy between potential planning from MRI alone by CT-synthetics generation and standard planning from CT	Comparison of the contours of target volumes and organs at risk and comparison of dose distributions (dosimetries)	3 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of the quality of images generated from MRI for dose calculation and images for verification of per-treatment positioning relative to the reference CT in an MRI-only workflow objective.	Comparison of CT-synthetic CT images generated from MRI to the reference CT and Comparison of shifts performed during patient repositioning	3 month

Collaborators and Investigators

• Sponsor: Institut Cancerologie de l'Ouest
• Investigators: Principal Investigator: Damien AUTRET, Institut de Cancerologie de L'Ouest

Study record dates

Study Major Dates

• Study Start (Actual): July 24, 2020
• Primary Completion (Actual): July 15, 2021
• Study Completion (Actual): July 15, 2021

Study Registration Dates

• First Submitted: January 8, 2021
• First Submitted That Met QC Criteria: January 8, 2021
• First Posted (Actual): January 12, 2021

Study Record Updates

• Last Update Posted (Actual): March 11, 2022
• Last Update Submitted That Met QC Criteria: March 10, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neoplasms; Urogenital Neoplasms; Neoplasms by Site; Genital Neoplasms, Male; Prostatic Diseases; Central Nervous System Neoplasms; Nervous System Neoplasms; Prostatic Neoplasms; Brain Neoplasms
• Other Study ID Numbers: ICO-2020-09

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No