The direct measurement using an imaging plate for coincidence of radiation centre and laser position in external radiation therapy

Toshiyuki Terunuma, Takeji Sakae, Akihiro Nohtomi, Yoshikazu Tsunashima

Research output: Contribution to journalArticle

2 Citations (Scopus)


A new method of quality assurance has been studied to measure coincidence of the radiation centre and a patient-setup laser position on a transverse plane to the beam at the isocentre. This measurement is achieved by using an imaging plate (IP). When radiation is applied to an IP, the energy is stored as trapped electrons. The number of electrons is decreased by local laser exposure. As a result, the radiation field produced by external beam irradiation is recorded as 'positive' information and the position of the patient-setup laser is recorded as 'negative' on an IP. The advantages of this method are the direct measurement, short time and high resolution. These are required for daily and monthly quality checks. We confirmed the advantage of this method by an experiment using a proton beam.

Original languageEnglish
Pages (from-to)N59-N63
JournalPhysics in Medicine and Biology
Issue number4
Publication statusPublished - Feb 21 2003


All Science Journal Classification (ASJC) codes

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging

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