Monocrystalline diamond detector for online monitoring during synchrotron microbeam radiotherapy.
J Synchrotron Radiat
; 30(Pt 6): 1076-1085, 2023 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-37815374
ABSTRACT
Microbeam radiation therapy (MRT) is a radiotherapy technique combining spatial fractionation of the dose distribution on a micrometric scale, X-rays in the 50-500â
keV range and dose rates up to 16 × 103â
Gyâ
s-1. Nowadays, in vivo dosimetry remains a challenge due to the ultra-high radiation fluxes involved and the need for high-spatial-resolution detectors. The aim here was to develop a striped diamond portal detector enabling online microbeam monitoring during synchrotron MRT treatments. The detector, a 550â
µm bulk monocrystalline diamond, is an eight-strip device, of height 3â
mm, width 178â
µm and with 60â
µm spaced strips, surrounded by a guard ring. An eight-channel ASIC circuit for charge integration and digitization has been designed and tested. Characterization tests were performed at the ID17 biomedical beamline of the European Synchrotron Radiation Facility (ESRF). The detector measured direct and attenuated microbeams as well as interbeam fluxes with a precision level of 1%. Tests on phantoms (RW3 and anthropomorphic head phantoms) were performed and compared with simulations. Synchrotron radiation measurements were performed on an RW3 phantom for strips facing a microbeam and for strips facing an interbeam area. A 2% difference between experiments and simulations was found. In more complex geometries, a preliminary study showed that the absolute differences between simulated and recorded transmitted beams were within 2%. Obtained results showed the feasibility of performing MRT portal monitoring using a microstriped diamond detector. Online dosimetric measurements are currently ongoing during clinical veterinary trials at ESRF, and the next 153-strip detector prototype, covering the entire irradiation field, is being finalized at our institution.
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MEDLINE
Assunto principal:
Radiometria
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Síncrotrons
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article