A SOFTWARE TOES FOR THE QUANTITATIVE-EVALUATION OF 3D DOSE CALCULATION ALGORITHMS

Current methods for evaluating modern radiation therapy treatment plan ning (RTP) systems include the manual superposition of calculated and measured isodose curves and the comparison of a limited number of calc ulated and measured point doses. Both techniques have significant limi tations in providing quantitative evaluations of the large number of d ose data generated by modern RTP systems. More sophisticated compariso n techniques have been presented in the literature, including dose-dif ference and distance-to-agreement (DTA) analyses. A software tool has been developed that uses superimposed isodose plots, dose-difference, and DTA distributions to quantify errors in computed dose distribution s. Dose-difference and DTA analyses are overly sensitive in regions of high- and low-dose gradient, respectively. The logical union of locat ions that fail both dose-difference and DTA acceptance criteria, terme d the composite evaluation, is calculated and displayed. The composite evaluation provides a method for the physicist to efficiently identif y regions that fail both the dose-difference and DTA acceptance criter ia. The tool provides a computer platform for the quantitative compari son of calculated and measured dose distributions. (C) 1998 American A ssociation of Physicists in Medicine. [S0094-2405(98)00410-6].