抄録
According to the supplier, the accuracy of the source strength of 192-iridium for high dose rate afterloaders is within the range of ±10%. To accurately determine the optimum dose for treatment, however, it is indispensable to calibrate the source strength at each institute. The authors experimentally measured the source strength of three different sources, at a source-detector distance of 8cm, by using a PMMA cylindrical phantom based on the DIN(Deutche Industrie Norm)protocol. According to the results, the source strength was within ±3.0% of the specification and the reproducibility of measurement was within 2.0%. Thus, the authors concluded that measurement using a PMMA cylindrical phantom with a fixed geometrical arrangement provides good reproducibility and is useful for measuring the source strength of iridium-192, which has a short source-detector distance.
