title: Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect.
abstract: The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter.
authors.affiliation: Department of Medical Physics and Engineering, Graduate School of Medicine, Hokkaido University, N-15 W-7 Kita-ku, Sapporo Hokkaido, 060-8638, Japan masayori@med.hokudai.ac.jp.
authors.forename: Masayori
authors.initials: M
authors.lastname: Ishikawa
authors.affiliation: Department of Radiology, Kawasaki Medical School Hospital, 577 Matsushima, Kurashiki Okayama, 701-0192, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Nagase
authors.affiliation: Department of Medical Physics, Hokkaido University Hospital, N-14 W-5 Kita-ku, Sapporo Hokkaido, 060-8648, Japan.
authors.forename: Taeko
authors.initials: T
authors.lastname: Matsuura
authors.affiliation: Department of Radiology, Kawasaki Medical School Hospital, 577 Matsushima, Kurashiki Okayama, 701-0192, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Hiratsuka
authors.affiliation: Department of Medical Physics, Hokkaido University Hospital, N-14 W-5 Kita-ku, Sapporo Hokkaido, 060-8648, Japan.
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Suzuki
authors.affiliation: Department of Medical Physics and Engineering, Graduate School of Medicine, Hokkaido University, N-15 W-7 Kita-ku, Sapporo Hokkaido, 060-8638, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Miyamoto
authors.affiliation: Department of Medical Physics and Engineering, Graduate School of Medicine, Hokkaido University, N-15 W-7 Kita-ku, Sapporo Hokkaido, 060-8638, Japan.
authors.forename: Kenneth Lee
authors.initials: KL
authors.lastname: Sutherland
authors.affiliation: Department of Radiology, Hokkaido University Hospital, N-14 W-5 Kita-ku, Sapporo Hokkaido, 060-8648, Japan.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Department of Radiology, Graduate School of Medicine, Hokkaido University, N-15 W-7 Kita-ku, Sapporo Hokkaido, 060-8638, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shirato
mesh_terms: D016477:Artifacts; D001417:Background Radiation; D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007909:Lenses; D008904:Miniaturization; D011874:Radiometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000295:instrumentation*; D012680:Sensitivity and Specificity
keywords: Cerenkov light removal; Ir-192 brachytherapy; SOF dosimeter; plastic scintillator dosimetry; pulse counting mode