Evaluation of Well-Type Chamber Calibration Factor for Measurement of Ir-192 Brachytherapy Source Over 10 Institutions

Abstract

This paper describes the evaluation of well-type chamber calibration factor for measurement Ir- 192 brachytherapy source. Data were collected at ten institutions of Ir-192 brachytherapy facilities. Calibration was carried out using the substitution method adopted from a protocol published by the International Atomic Energy Agency. The well-type chamber standard used was HDR-1000 Plus. The results obtained that NAKS for well-type chamber from PTW manufacturers has a range of values from 9.063 × 105-9.875 × 105 Gy m2 h−1 A−1 with an average value 9.522 × 105 Gy m2 h−1 A−1, while the well-type chamber from Standard Imaging manufacturers has a range of values from 4.634 × 105-4.662 × 105 Gy m2 h−1 A−1 with an average value 4.648 × 105 Gy m2 h−1 A−1. The range of deviations obtained between NAKS−new and NAKS−old ranges from 0.8% to -1.8%, while the range of normalization results of NAKS−new to the average value of NAKS−new ranges from 0.952-1.029. There was one calibration factor that has a deviation of more than 1% over the NAKS−old. Based on the calculation of uncertainty, all the calibration factor results obtained were still within the accepted range.