ESTRO 2024 - Abstract Book

S3856

Physics - Image acquisition and processing

ESTRO 2024

References:

[1] Parodi, K. Heavy ion radiography and tomography. Physica medica 30.5 (2014): 539-543.

[2] Brooks ED, Ning MS, Verma V, Zhu XR, Chang JY. Proton therapy for non-small cell lung cancer: the road ahead. Translational Lung Cancer Research. 2019 Sep;8(Suppl 2): S202.

[3] Simard M, Robertson D, Fullarton R, Royle G, Beddar S, Collins-Fekete CA. Integrated-mode proton radiography with 2D lateral projections. Under review in Physics in Medicine and Biology.

1705

Poster Discussion

First head and neck radiotherapy planning based on MRI quantitative proton density images

Laura Sayaque 1 , Benjamin Leporq 1 , Frank Pilleul 1,2 , Oivier Hamelin 2 , Charlène Bouyer 2,3 , Vincent Gregoire 3 , Olivier Beuf 1 1 Univ Lyon, INSA ‐ Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1294, F ‐ 69100, Lyon, France. 2 CRLCC Léon Bérard, Département de Radiologie, Lyon, France. 3 CRLCC Léon Bérard, Département de Radiothérapie, Lyon, France

Purpose/Objective:

MRI is currently used for the identification of the organs at risk (OAR) in the radiotherapy (RT) routine, the high contrast between soft tissues offering an easier depiction of tumors and OARs. Moreover, MRI is increasingly used for direct RT planning in prostate and brain localizations. In that case, the electronic density maps, which are necessary for the dose planning, are obtained using several methods in the literature based on machine learning, atlas registration or density assignment [1,2]. For head and neck region, such methods are still not commonly used due to larger variability of tissues and morphologies. Recently, Demol et al. [3] proposed to perform the dose planning based on the knowledge of the hydrogen content of the tissues, attributing the properties of oxygen to the other atoms. Since MRI is based on the imaging of the proton, specific sequences [4] can allow direct proton density (PD) measurement, corresponding after calibration to the hydrogen content.

In this work, we set up a head and neck protocol for the quantification of the PD [5] in order to build a synthetic CT (sCT).

Material/Methods: