Comprehensive dosimetric characterization of novel silicon carbide detectors with UHDR electron beams for FLASH radiotherapy.

Autor:	Milluzzo G; National Institute of Nuclear Physics (INFN), Catania Division, Catania, Italy., De Napoli M; National Institute of Nuclear Physics (INFN), Catania Division, Catania, Italy., Di Martino F; Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Pisa, Italy.; Fisica Sanitaria, Azienda Ospedaliero Universitaria Pisa AOUP, Pisa, Italy.; National Institute of Nuclear Physics (INFN), Pisa Division, Pisa, Italy., Amato A; STLab srl, Catania, Italy.; National Institute of Nuclear Physics (INFN), Laboratori Nazionali del Sud, Catania, Italy., Del Sarto D; Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Pisa, Italy.; Fisica Sanitaria, Azienda Ospedaliero Universitaria Pisa AOUP, Pisa, Italy., D'Oca MC; National Institute of Nuclear Physics (INFN), Catania Division, Catania, Italy.; Department of Physics and Chemistry 'Emilio Segrè', University of Palermo, Palermo, Italy., Marrale M; National Institute of Nuclear Physics (INFN), Catania Division, Catania, Italy.; National Institute of Nuclear Physics (INFN), Laboratori Nazionali del Sud, Catania, Italy., Masturzo L; Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Pisa, Italy.; Fisica Sanitaria, Azienda Ospedaliero Universitaria Pisa AOUP, Pisa, Italy.; SIT-Sordina, Aprilia, Italy., Medina E; Physics Department, University of Torino, Torino, Italy.; National Institute of Nuclear Physics (INFN), Torino Division, Torino, Italy., Okpuwe C; National Institute of Nuclear Physics (INFN), Catania Division, Catania, Italy.; Physics Department, University of Catania, Catania, Italy.; Department of Physics, Federal University of Technology Owerri, Owerri, Nigeria., Pensavalle JH; Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Pisa, Italy.; Fisica Sanitaria, Azienda Ospedaliero Universitaria Pisa AOUP, Pisa, Italy.; SIT-Sordina, Aprilia, Italy., Vignati A; Physics Department, University of Torino, Torino, Italy.; National Institute of Nuclear Physics (INFN), Torino Division, Torino, Italy., Camarda M; STLab srl, Catania, Italy.; SenSiC GmbH, Villigen, Switzerland., Romano F; National Institute of Nuclear Physics (INFN), Catania Division, Catania, Italy.; Particle Therapy Research Center (PARTREC), Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Jazyk:	angličtina
Zdroj:	Medical physics [Med Phys] 2024 Sep; Vol. 51 (9), pp. 6390-6401. Date of Electronic Publication: 2024 May 21.
DOI:	10.1002/mp.17172
Abstrakt:	Background: The extremely fast delivery of doses with ultra high dose rate (UHDR) beams necessitates the investigation of novel approaches for real-time dosimetry and beam monitoring. This aspect is fundamental in the perspective of the clinical application of FLASH radiotherapy (FLASH-RT), as conventional dosimeters tend to saturate at such extreme dose rates. Purpose: This study aims to experimentally characterize newly developed silicon carbide (SiC) detectors of various active volumes at UHDRs and systematically assesses their response to establish their suitability for dosimetry in FLASH-RT. Methods: SiC PiN junction detectors, recently realized and provided by STLab company, with different active areas (ranging from 4.5 to 10 mm 2 ) and thicknesses (10-20 µm), were irradiated using 9 MeV UHDR pulsed electron beams accelerated by the ElectronFLASH linac at the Centro Pisano for FLASH Radiotherapy (CPFR). The linearity of the SiC response as a function of the delivered dose per pulse (DPP), which in turn corresponds to a specific instantaneous dose rate, was studied under various experimental conditions by measuring the produced charge within the SiC active layer with an electrometer. Due to the extremely high peak currents, an external customized electronic RC circuit was built and used in conjunction with the electrometer to avoid saturation. Results: The study revealed a linear response for the different SiC detectors employed up to 21 Gy/pulse for SiC detectors with 4.5 mm 2 /10 µm active area and thickness. These values correspond to a maximum instantaneous dose rate of 5.5 MGy/s and are indicative of the maximum achievable monitored DPP and instantaneous dose rate of the linac used during the measurements. Conclusions: The results clearly demonstrate that the developed devices exhibit a dose-rate independent response even under extreme instantaneous dose rates and dose per pulse values. A systematic study of the SiC response was also performed as a function of the applied voltage bias, demonstrating the reliability of these dosimeters with UHDR also without any applied voltage. This demonstrates the great potential of SiC detectors for accurate dosimetry in the context of FLASH-RT. (© 2024 The Author(s). Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)
Databáze:	MEDLINE
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