MISC

国際誌
2016年10月

Characterization of stochastic noise and post-irradiation density growth for reflective-type radiochromic film in therapeutic photon beam dosimetry.

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)
  • Takeshi Kamomae
  • ,
  • Masataka Oita
  • ,
  • Naoki Hayashi
  • ,
  • Motoharu Sasaki
  • ,
  • Hideki Aoyama
  • ,
  • Hiroshi Oguchi
  • ,
  • Mariko Kawamura
  • ,
  • Hajime Monzen
  • ,
  • Yoshiyuki Itoh
  • ,
  • Shinji Naganawa

32
10
開始ページ
1314
終了ページ
1320
記述言語
英語
掲載種別
DOI
10.1016/j.ejmp.2016.07.091
出版者・発行元
ELSEVIER SCI LTD

The aim of this study is to investigate the dosimetric uncertainty of stochastic noise and the postirradiation density growth for reflective-type radiochromic film to obtain the appropriate dose from the exactly controlled film density. Film pieces were irradiated with 6-MV photon beams ranging from 0 to 400 cGy. The pixel values (PVs) of these films were obtained using a flatbed scanner at elapsed times of 1 min to 120 h between the end of irradiation and the film scan. The means and standard deviations (SDs) of the PVs were calculated. The SDs of the converted dose scale, u(sd), and the dose increases resulting from the PV increases per +/- 29 min at each elapsed time, u(time), were computed. The combined dose uncertainties from these two factors, u(c), were then calculated. A sharp increase in the PV occurred within the first 3 h after irradiation, and a slight increase continued from 3 h to 120 h. usd was independent of post-irradiation elapsed time. Sharp decreases in utime were obtained within 1 h after irradiation, and slight decreases in utime were observed from 1 to 24 h after irradiation. uc first decreased 1 h after irradiation and remained constant afterward. Assuming that the post-irradiation elapsed times of all of the related measurements are synchronized within +/- 29 min, the elapsed time should be at least 1 h in our system. It is important to optimize the scanning protocol for each institution with consideration of the required measurement uncertainty and acceptable latency time. (C) 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

リンク情報
DOI
https://doi.org/10.1016/j.ejmp.2016.07.091
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/27473441
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000390595300017&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.ejmp.2016.07.091
  • ISSN : 1120-1797
  • eISSN : 1724-191X
  • PubMed ID : 27473441
  • Web of Science ID : WOS:000390595300017

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