Characteristics of microSilicon diode detector for electron beam dosimetry. (24th September 2021)

• Record Type: Journal Article
• Authors: Akino, Yuichi; Das, Indra J; Fujiwara, Masateru; Kaneko, Akari; Masutani, Takashi; Mizuno, Hirokazu; Isohashi, Fumiaki; Suzuki, Osamu; Seo, Yuji; Tamari, Keisuke; Ogawa, Kazuhiko
• Is Part Of: Journal of radiation research. Volume 62:Number 6(2021)
• Page Start: 1130
• Page End: 1138
• Publication Date: 2021-09-24
• Subjects: electron beam -- diode detector -- radiotherapy -- beam data commissioning; Radiology, Medical -- Periodicals; Radiobiology -- Periodicals; Radiation -- Periodicals; 616.0757
• DOI: 10.1093/jrr/rrab085
• Languages: English
• ISSNs: 0449-3060

Abstract

Abstract: A microSilicon™ (PTW type 60023), a new unshielded diode detector succeeding Diode E (model 60017, PTW), was characterized for electron beam dosimetry and compared with other detectors. Electron beams generated from a TrueBeam linear accelerator were measured using the microSilicon, Diode E, and microDiamond synthetic single-crystal diamond detector. Positional accuracy of microSilicon was measured by data collected in air and water. The percent depth dose (PDD), off-center ratio (OCR), dose–response linearity, dose rate dependence, and cone factors were evaluated. The PDDs were compared with data measured using a PPC40 plane-parallel ionization chamber. The maximum variations of depth of 50% and 90% of the maximum dose, and practical depth among all detectors and energies were 0.9 mm. The maximum variations of the bremsstrahlung dose among all detectors and energies were within 0.3%. OCR showed good agreement within 1% for the flat and tail regions. The microSilicon detector showed a penumbra width similar to microDiamond, whereas Diode E showed the steepest penumbra shape. All detectors showed good dose–response linearity and stability against the dose rate; only Diode E demonstrated logarithmic dose rate dependency. The cone factor measured with microSilicon was within ±1% for all energies and cone sizes. We demonstrated that the characteristics of microSilicon is suitable for electron beam dosimetry. The microSilicon detector can be a good alternative for electron beam dosimetry in terms of providing an appropriate PDD curve without corrections, high spatial resolution for OCR measurements and cone factors.