A cost-effective monitoring technique in particle therapy via uncollimated prompt gamma peak integration

Krimmer, J.; Angellier, G.; Balleyguier, L.; Dauvergne, D.; Freud, N.; Herault, J.; Letang, J. M.; Mathez, H.; Pinto, M.; Testa, E. und Zoccarato, Y. (2017): A cost-effective monitoring technique in particle therapy via uncollimated prompt gamma peak integration. In: Applied Physics Letters, Bd. 110, Nr. 15, 154102

Abstract

For the purpose of detecting deviations from the prescribed treatment during particle therapy, the integrals of uncollimated prompt gamma-ray timing distributions are investigated. The intention is to provide information, with a simple and cost-effective setup, independent from monitoring devices of the beamline. Measurements have been performed with 65MeV protons at a clinical cyclotron. Prompt gamma-rays emitted from the target are identified by means of time-of-flight. The proton range inside the PMMA target has been varied via a modulator wheel. The measured variation of the prompt gamma peak integrals as a function of the modulator position is consistent with simulations. With detectors covering a solid angle of 25 msr (corresponding to a diameter of 3-4 in. at a distance of 50 cm from the beam axis) and 10(8) incident protons, deviations of a few per cent in the prompt gamma-ray count rate can be detected. For the present configuration, this change in the count rate corresponds to a 3mm change in the proton range in a PMMA target. Furthermore, simulation studies show that a combination of the signals from multiple detectors may be used to detect a misplacement of the target. A different combination of these signals results in a precise number of the detected prompt gamma rays, which is independent on the actual target position. Published by AIP Publishing.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0003-6951
• Sprache: Englisch