
==== Front
medRxiv
MEDRXIV
medRxiv
Cold Spring Harbor Laboratory

10.1101/2024.08.29.24312591
preprint
1
Article
Technical Development and In Silico Implementation of SyntheticMR in Head and Neck Adaptive Radiation Therapy: A Prospective R-IDEAL Stage 0/1 Technology Development Report
McCullum Lucas http://orcid.org/0000-0001-9788-7987

Mulder Samuel http://orcid.org/0000-0001-5185-4805

West Natalie http://orcid.org/0009-0007-0211-8845

Aghoghovbia Robert http://orcid.org/0009-0008-2944-4584

Ali Alaa Mohamed Shawky http://orcid.org/0000-0001-7472-3701

Scott Hayden http://orcid.org/0000-0003-1066-1999

Salzillo Travis C. http://orcid.org/0000-0001-6271-9879

Ding Yao http://orcid.org/0000-0002-0559-5846

Dresner Alex http://orcid.org/0000-0002-0469-6012

Subashi Ergys
Ma Dan http://orcid.org/0000-0003-1664-9579

Stafford R. Jason http://orcid.org/0000-0003-4091-8417

Hwang Ken-Pin http://orcid.org/0000-0002-8196-3794

Fuller Clifton D. http://orcid.org/0000-0002-5264-3994

31 8 2024
2024.08.29.24312591https://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.
http://medrxiv.org/lookup/doi/10.1101/2024.08.29.24312591
nihpp-2024.08.29.24312591.pdf
Abstract

Objective

The purpose of this study was to investigate the technical feasibility of integrating the quantitative maps available from SyntheticMR into the head and neck adaptive radiation oncology workflow. While SyntheticMR has been investigated for diagnostic applications, no studies have investigated its feasibility and potential for MR-Simulation or MR-Linac workflow. Demonstrating the feasibility of using this technique will facilitate rapid quantitative biomarker extraction which can be leveraged to guide adaptive radiation therapy decision making.

Approach

Two phantoms, two healthy volunteers, and one patient were scanned using SyntheticMR on the MR-Simulation and MR-Linac devices with scan times between four to six minutes. Images in phantoms and volunteers were conducted in a test/retest protocol. The correlation between measured and reference quantitative T1, T2, and PD values were determined across clinical ranges in the phantom. Distortion was also studied. Contours of head and neck organs-at-risk (OAR) were drawn and applied to extract T1, T2, and PD. These values were plotted against each other, clusters were computed, and their separability significance was determined to evaluate SyntheticMR for differentiating tumor and normal tissue.

Main Results

The Lin’s Concordance Correlation Coefficient between the measured and phantom reference values was above 0.98 for both the MR-Sim and MR-Linac. No significant levels of distortion were measured. The mean bias between the measured and phantom reference values across repeated scans was below 4% for T1, 7% for T2, and 4% for PD for both the MR-Sim and MR-Linac. For T1 vs. T2 and T1 vs. PD, the GTV contour exhibited perfect purity against neighboring OARs while being 0.7 for T2 vs. PD. All cluster significance levels between the GTV and the nearest OAR, the tongue, using the SigClust method was p < 0.001.

Significance

The technical feasibility of SyntheticMR was confirmed. Application of this technique to the head and neck adaptive radiation therapy workflow can enrich the current quantitative biomarker landscape.
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