@article{oai:tsukuba.repo.nii.ac.jp:00041166, author = {照沼, 利之 and 榮, 武二 and 納冨, 昭弘 and 綱島, 義一 and TERUNUMA, Toshiyuki and SAKAE, Takeji and NOHTOMI, Akihiro and TSUNASHIMA, Yoshikazu}, issue = {4}, journal = {Physics in Medicine and Biology}, month = {Jan}, note = {A new method of quality assurance has been studied to measure coincidence of the radiation center and a patient-setup laser position on a transverse plane to the beam at the isocenter. This measurement is achieved by using an imaging plate (IP). When a 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" one 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 proton beam.}, pages = {N1--N5}, title = {The direct measurement using an imaging plate for coincidence of radiation center and laser position in external radiation therapy.}, volume = {48}, year = {2003} }