Near-field coded-mask technique and its potential for proton therapy monitoring

• DOI: 10.48550/arxiv.2307.01203
• Publication Date: 2023-01-01
• Authors: R. Hetzel; Vitalii Urbanevych; Andreas Bolke; Jonas Kasper; Magdalena Kołodziej; Monika Kercz; A. Magiera; Florian Mueller; S. Müller; M. Rafecas; K. Rusiecka; David Schug; Volkmar Schulz; A. Stahl; Bjoern Weissler; Ming-Liang Wong; A. Wrońska
• Keywords: Collimator; Lyso-

Objective. Prompt-gamma imaging encompasses several approaches for online monitoring of beam range or deposited dose distribution in proton therapy. We test one the techniques - a coded mask approach both experimentally and via simulations. Approach. Two setups have been investigated experimentally. Each them comprised structured tungsten collimator form MURA LYSO:Ce scintillation detector fine granularity. The differed dimensions operation mode (1D 2D imaging). A series measurements with radioactive sources conducted, testing setups' performance near-field gamma imaging. Additionally, Monte Carlo simulations larger setup same type were investigating its realistic source occurring during Main results. images point-like reconstructed from two smallscale prototypes' data using MLEM algorithm constitute experimental proof principle coded-mask modality, 1D mode. Their precision allowed us to calibrate out certain systematic offsets appearing due misalignment elements. simulation full-scale yielded mean distal falloff retrieval 0.72 mm studies energy 89.5-107.9 MeV 1x10^8 protons (typical number single spots). implemented image reconstruction is relatively fast typical procedure needs seconds. Significance. Coded-mask appears valid option therapy monitoring. results let conclude that proposed fullscale competitive knife-edge-shaped multiparalell slit cameras by other groups.