ESTRO 2024 - Abstract Book

S4595

Physics - Optimisation, algorithms and applications for ion beam treatment planning

ESTR0 2024

Keywords: Proton Arc Therapy, System controller design

References:

1. Ding, X. et al. Spot-Scanning Proton Arc (SPArc) Therapy: The First Robust and Delivery-Efficient Spot-Scanning Proton Arc Therapy. Int. J. Radiat. Oncol. Biol. Phys. 96, 1107–1116 (2016).

2. Li, X. et al. The first prototype of spot-scanning proton arc treatment delivery. Radiother. Oncol. 137, 130–136 (2019).

453

Proffered Paper

New particle therapy method to hypoxic tumor: LET boost by particle arc irradiation (LEOPARD)

Guangru Li 1,2 , Lennart Volz 1 , Olga Sokol 1 , Emanuele Scifoni 3 , Marco Durante 1,4 , Qiang Li 2 , Christian Graeff 1,5

1 GSI Helmholtzzentrum für Schwerionenforschung GmbH, Biophysics, Darmstadt, Germany. 2 Institute of Modern Physics (IMP), Biomedical, Lanzhou, China. 3 National Institute for Nuclear Physics (INFN), Trento Institute for Fundamental Physics and Applications (TIFPA), Povo, Italy. 4 Technical University of Darmstadt, Institute of Condensed Matter Physics, Darmstadt, Germany. 5 Technical University of Darmstadt, Institute of Electrical Engineering and Information Technology, Darmstadt, Germany

Purpose/Objective:

Tumor hypoxia is identified as a major challenge in radiation therapy [1]. One of the key solutions to tumor hypoxia is to increase the linear energy transfer (LET) in the hypoxic tumor [2], [3]. Heavy ions have a higher LET than photons or protons, meaning that they can increase biological effectiveness against hypoxic tumors. Recently, the significant advancements have been achieved in particle arc irradiation by using proton and heavy ions [4]-[7]. Based on them, we introduce a new particle therapy method to treat hypoxic tumor: LE t b O ost by P article AR c irra D iation(LEOPARD). By concentrating the arc delivery to the hypoxic subvolume, the possible LET increase is exploited optimally to overcome radioresistance.

Material/Methods:

In this work, we use the TRiP98 treatment planning system [8], [9] to compare LEOPARD and IMPT Boost treatment plans. In every treatment plan, we set prescription dose to CTV as 3 Gy and boost dose to hypoxic VOI as 4 Gy. LEM modal [10] was used to calculate the biological dose. Firstly, we created an artificial hypoxic subvolume (HypoxiaVOI). Then, for LEOPARD plans, we designed arc fields (0° to 360°, step = 2°, 180 control points, single energy for each point) to boost dose in HypoxiaVOI and 2 opposing Left-Right (LR) fields (90° and -90°) to achieve the prescription dose to CTV. For IMPT Boost plans, we designed 2 opposing LR fields (90° and -90°) as normal IMPT fields to CTV, and another