No Cover Image

Journal article 100 views

Electron contamination suppression in transmission detectors for radiotherapy

Lana Beck Orcid Logo, Chiara De Sio, Richard Hugtenburg Orcid Logo, Jaap Velthuis

Physics in Medicine & Biology, Volume: 68, Issue: 21, Start page: 215014

Swansea University Authors: Richard Hugtenburg Orcid Logo, Jaap Velthuis

Full text not available from this repository: check for access using links below.

Abstract

Objective. Higher energy and intensity radiotherapy beams are being used, in part, due to the increased spatial accuracy of treatments. However, higher intensity beams can result in a larger total dose error, motivating the increasing need for real-time dose monitoring. We are developing a thin, rea...

Full description

Published in: Physics in Medicine & Biology
ISSN: 0031-9155 1361-6560
Published: IOP Publishing 2023
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa67934
Abstract: Objective. Higher energy and intensity radiotherapy beams are being used, in part, due to the increased spatial accuracy of treatments. However, higher intensity beams can result in a larger total dose error, motivating the increasing need for real-time dose monitoring. We are developing a thin, real-time upstream monolithic active pixel sensor based system for beam monitoring with excellent precision on measuring the beam shape. Here we present a method to additionally provide dosimetry by adding thin conversion material in strips to the surface of the detector, a grating structure. Approach. By modulating the thickness of the conversion material to minimally disturb the contamination electron signal while enhancing the photon signal, the difference in these signals can be used to extract a photon-only signal, and hence dose. The simulation software Gate, based on Geant4, is utilised to study whether well functioning gratings can be better made from aluminium or copper and to optimise the thickness of a copper grating. Main results. It is possible to enhance the photon signal by a factor 6.7 (7.7) compared to the bare sensor for a 5.8 (6.7) MV beam, without modulation of the signal due to beam electrons. Significance. The grating can be used to perform dosimetry in real-time using a thin upstream detector.
College: Faculty of Medicine, Health and Life Sciences
Issue: 21
Start Page: 215014