AbstractID: 8836 Title: Analyses and Evaluations of Accuracies of Dose Validations for
IMRT Inverse Treatment Planning System
In the past few years, we have treated 321 IMRT patients. These patients were planned by three different inverse treatment planning
systems, Corvus (62 patients), ADAC (193 patients), and Cadplan (66 patients). ADAC’s plans were delivered by the "step-and-shoot"
on Siemen’s machine while Corvus and Cadplan plans were delivered by "sliding window" on Varian machines. Prior to their
treatments, each one of the patient’s plans was carefully validated for the plan’s calculated dose and monitor units by both ion chamber
measurements and film dosimetry in a phantom. There are six sets of data obtained by three planning systems with two methods of
measurements. Due to random nature of the data dispersion, a normal distribution was assumed to each data set for statistical analyses.
The means and standard deviations of each set were calculated. Results have clearly shown that 1. For Corvus, the means of the ratios
of the measured to the calculated doses are 1.0127 with ion chamber and 1.008 with film 2. For Cadplan, they are 0.9943 for ion
chamber and 0.9972 for film 3. For ADAC, 1.0200 for ion chamber and 1.0117 for film. In conclusion, although the three systems
used different dose calculation algorithms, they all, however, are within 2% which is acceptable.