Work

Secondary Particle Interactions in a Compton Camera Designed for in vivo Range Verification of Proton Therapy

Year: 2020

Type: article

Abstract: The purpose of this study was to determine the types, proportions, and energies of secondary particle interactions in a Compton camera (CC) during the delivery of clinical proton beams. The delivery of clinical proton pencil beams ranging from 70 to 200 MeV incident on a water phantom was simulated using Geant4 software (version 10.4). The simulation included a CC similar to the configuration of a Polaris J3 CC designed to image prompt gammas (PGs) emitted during proton beam irradiation for the purpose of in vivo range verification. The interaction positions and energies of secondary particles in each CC detector module were scored. For a 150-MeV proton beam, a total of 156 688(575) secondary particles per 108protons, primarily composed of gamma rays (46.31%), neutrons (41.37%), and electrons (8.88%), were found to reach the camera modules, and 79.37% of these particles interacted with the modules. Strategies for using CCs for proton range verification should include methods of reducing the large neutron backgrounds and low-energy non-PG radiation. The proportions of interaction types by module from this study may provide information useful for background suppression.

Source: IEEE Transactions on Radiation and Plasma Medical Sciences

DOI: 10.1109/trpms.2020.3030166

Authors: Rajesh Panthi, Paul Maggi, Stephen Peterson, Dennis Mackin, Jerimy Polf, Sam Beddar

Institutions: The University of Texas MD Anderson Cancer Center, University of Maryland, Baltimore, University of Cape Town

Language: English

Topic: Radiation Therapy and Dosimetry

Subfield: Pulmonary and Respiratory Medicine

Field: Medicine

Domain: Health Sciences

Open Access status: green

Funder: National Cancer Institute

Award: Prompt Gamma Imaging for the in-vivo range verification during proton radiotherapy