16 January 2018 Radiotherapy fiber dosimeter probes based on silver-only coated hollow glass waveguides
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Manifestation of Čerenkov radiation as a contaminating signal is a significant issue in radiation therapy dose measurement by fiber-coupled scintillator dosimeters. To enhance the scintillation signal transmission while minimizing Čerenkov radiation contamination, we designed a fiber probe using a silver-only coated hollow waveguide (HWG). The HWG with scintillator inserted in its tip, embedded in tissue-mimicking phantoms, was irradiated with clinical electron and photon beams generated by a medical linear accelerator. Optical spectra of the irradiated tip were taken using a fiber spectrometer, and the signal was deconvolved with a linear fitting algorithm. The resultant decomposed spectra of the scintillator with and without Čerenkov correction were in agreement with measurements performed by a standard electron diode and ion chamber for electron and photon beam dosimetry, respectively, indicating the minimal effect of Čerenkov contamination in the HWG-based dosimeter. Furthermore, compared with a silver/dielectric-coated HWG fiber dosimeter design, we observed higher signal transmission in the design based on the use of silver-only HWG.
© 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Arash Darafsheh, Jeffrey E. Melzer, James A. Harrington, Alireza Kassaee, Jarod C. Finlay, "Radiotherapy fiber dosimeter probes based on silver-only coated hollow glass waveguides," Journal of Biomedical Optics 23(1), 015006 (16 January 2018). https://doi.org/10.1117/1.JBO.23.1.015006 . Submission: Received: 6 September 2017; Accepted: 21 December 2017
Received: 6 September 2017; Accepted: 21 December 2017; Published: 16 January 2018

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