ESTRO 2024 - Abstract Book

S3503

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

The mean doses are reduced by 1.2 Gy (bladder), 1.2 Gy (bowel), 2.6 Gy (rectum), 1.1 Gy (ipsilateral femoral head), and 0.5 Gy (contralateral femoral head) for colli-DYMBER compared to coplanar VMAT. D 2% to the normal tissue is reduced by 4.6 Gy for colli-DYMBER compared to coplanar VMAT. Dose volume histograms for the analyzed case are reported in Fig. 2.

Fig. 2 Dose volume histograms for colli-DYMBER (solid lines) and coplanar VMAT (dashed lines) plans.

Conclusion:

A dosimetrically motivated pathfinding approach simultaneously optimizing photon and electron contributions was successfully developed for colli-DYMBER. For the analyzed case, improved OAR sparing and superior target coverage were observed for the colli-DYMBER plan compared to the coplanar VMAT plan. Next, more clinically motivated cases will be considered to assess the generalizability of the method.

Supported by Varian, a Siemens Healthineers Company and SNSF grant 200021_185366.

Dose calculations and optimizations were performed on UBELIX (www.id.unibe.ch/hpc), the high-performance cluster at the University of Bern.

Keywords: Non-coplanar radiotherapy, mixed-beam radiotherapy