ABSTRACT
This paper describes the establishment by the Institute of Nuclear Energy Research (INER, Taiwan) of the reference air kerma rate (RAKR) calibration standard for measurement of high-dose rate (HDR) (192)Ir brachytherapy source strength. A bilateral comparison has been made in the RAKR standards for HDR (192)Ir brachytherapy sources at the INER and Physikalisch-Technische Bundesanstalt (PTB, Germany) and the measurement difference was within the overall standard uncertainty and showed good agreement between the two calibration standard systems established at the INER and the PTB. Besides, INER also worked with 20 domestic hospitals to organise an on-site measurement comparison programme to explore the status of HDR (192)Ir brachytherapy source strength determination in Taiwan. The comparison results presented the ratios of RAKR with vendor values, as determined by INER and hospitals from the programme. The ratios fall in all cases within the ± 3 % guaranteed by the vendors for a coverage factor of k = 2 or at 95 % confidence level.
Subject(s)
Brachytherapy , Iridium Radioisotopes/therapeutic use , Radiotherapy Planning, Computer-Assisted/standards , Calibration , Germany , Humans , Radiotherapy Dosage , TaiwanABSTRACT
An alpha/beta emitter measurement system used to calibrate surface sources following the guidelines of ISO 8769 has been established in Institute of Nuclear Energy Research (INER) around the year 2000. This system consists of a windowless proportional counter with a uniformity of 0.28% when measuring the emission rate of a source on a centered area of 100 mm x 150 mm, and a uniformity of 0.62% when the source area was 150 mm x 200 mm. Four 100 mm x 150 mm sources (90Sr + 90Y, 36Cl, 14C and 241Am) had been measured by this system. The measurement results of the above four sources when compared with those of National Physical Laboratory, UK (NPL) showed difference between the two laboratories of < 1%.
