title: [Dosimetry study using an anthropomorphic head phantom for stereotactic radiosurgery]
abstract: A dosimetry study using an anthropomorphic head phantom (Radiosurgery Verification Phantom (RSVP)) and a micro-ionization chamber for stereotactic radiosurgery was performed. To study the characteristics of the micro-ionization chamber, tissue maximum ratios (TMRs), off-axis ratios (OARs) and output factors were measured and compared, using a Si semiconductor detector and the film method. The directional difference in sensitivity and the effect of the polarity of the micro-ionization chamber were measured. According to the results obtained, the measured values and the values obtained through calculation were in agreement within 6.3%. The difference was due to the larger size of the micro-ionization chamber as compared to the other method. Therefore we applied a correction for this size effect and obtained better agreement within 2%. On the basis of the results of the present study we were able to confirm the overall accuracy and establish a means of quality assurance (QA) for stereotactic radiosurgery.
authors.affiliation: Central Department of Radiology, Izumisano Municipal Hospital.
authors.forename: Naoko
authors.initials: N
authors.lastname: Maeda
authors.forename: Masanori
authors.initials: M
authors.lastname: Komi
authors.forename: Nobuo
authors.initials: N
authors.lastname: Murao
authors.forename: Satoru
authors.initials: S
authors.lastname: Endo
authors.forename: Masaharu
authors.initials: M
authors.lastname: Hoshi