Comparison of calibration procedures for 192Ir high-dose-rate brachytherapy sources.

Purpose: To compare the efficacy of different calibration procedures for 192Ir high-dose-rate (HDR) brachytherapy sources and to determine their suitability in clinical practice. In addition the manufacturer's calibration is compared with our experimental measurements so that the accuracy of the source strength on the manufacturer certificate which is supplied with each new 192Ir source can be accessed.

Methods And Materials: We compared three types of calibration system: well-type chambers (HDR-1000 and SDS), cylindrical phantom, and plate phantom.

Application of the Monte Carlo integration (MCI) method for calculation of the anisotropy of 192Ir brachytherapy sources.

Source anisotropy is a very important factor in the brachytherapy quality assurance of high-dose rate (HDR) 192Ir afterloading stepping sources. If anisotropy is not taken into account then doses received by a brachytherapy patient in certain directions can be in error by a clinically significant amount. Experimental measurements of anisotropy are very labour intensive.

A conformal index (COIN) to evaluate implant quality and dose specification in brachytherapy.

Purpose: To propose a new index (COIN) that can be easily understood and computed to assess high dose rate (HDR) brachytherapy interstitial implant quality and dose specification and is an improvement on existing indexes.

Methods And Materials: The COIN index is based on an extension of dose-volume histograms and employs an analogous concept to that of cost-benefit analysis, which has already been applied to quality-of-life assessments for two alternative treatment protocols. The COIN index calculation methodology is shown for two cases: with and without critical structures.