ESTRO 2024 - Abstract Book

S3858

Physics - Image acquisition and processing

ESTRO 2024

In Table 1, Dmax is the maximum dose no to reach for relevant OARs, Dmed is the prescribed median dose for the tumor volumes, CT corresponds to dose resulting from the CT-based dosimetry and sCT corresponds to the dose resulting from the PD-based sCT dosimetry. The organ POST corresponds to the area containing the cervical spinal cord and the nape of the neck.

Organs

Dmax (Gy)

CT (Gy)

sCT (Gy)

Lips

30 30 45 80

20.7 30.1 30.4 70.1

19.7

POST

32

Spinal cord

31.3 71.4

Trachea

Target volumes

Dmed (Gy)

CT (Gy)

sCT (Gy)

PTV BR PTV HR

54.25

62.4 68.4

62.2 68.7

70

Conclusion:

Our work demonstrated for the first time that PD quantification assessed by MRI could be linked directly to the Hounsfield Unit leading to sCT. This work focuses on the head and neck area. Due to the large number of OARs (brainstem, optic nerves…) in this region and the large field of view required (from the top of the head to the upper part of the humerus), it has not been much explored in the literature. The encouraging results obtained on this first patient need to be confirmed with more patients.

Keywords: Head and neck, MRI, proton density

References:

1. Vanquin « Planification de la radiothérapie du cancer de la prostate par l’imagerie par résonance magnétique » Cancer/Radiothérapie

2. Kazemifar « Dosimetric evaluation of synthetic CT generated with GANs for MRI ‐ only proton therapy treatment planning of brain tumors » Journal of Applied Clinical Medical Physics