[Dosimetry study using an anthropomorphic head phantom for stereotactic radiosurgery].

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.