RapidPlan, a commercial knowledge-based optimizer, has been tested on head and neck, lung, esophageal, breast, liver, and prostate cancer patients. To appraise its performance on VMAT planning with simultaneous integrated boosting (SIB) for rectal cancer, this study configured a DVH (dose-volume histogram) estimation model consisting 80 best-effort manual cases of this type. Using the model- generated objectives, the MLC (multileaf collimator) sequences of other 70 clinically approved plans were reoptimized, while the remaining parameters, such as field geometry and photon energy, were maintained. Dosimetric outcomes were assessed by comparing homogeneity index (HI), conformal index (CI), hot spots (volumes receiving over 107% of the prescribed dose, Symbol), mean dose and dose to the 50% volume of femoral head (Symbol and Symbol), and urinary bladder (Symbol and Symbol), and the mean DVH plotting. Paired samples t-test or Wilcoxon signed-rank test suggested that comparable CI were achieved by RapidPlan (Symbol for Symbol, and Symbol for PTV) and original plans (Symbol for Symbol and Symbol for PTV), respectively Symbol. Slightly improved HI of planning target volume Symbol and PTV were observed in the RapidPlan cases (Symbol for Symbol, and Symbol for PTV) than the original plans (Symbol for Symbol and Symbol for PTV), Symbol. More cases with positive Symbol were found in the original (18 plans) than the RapidPlan group (none). RapidPlan significantly reduced the Symbol (by Symbol from Symbol to Symbol), Symbol (by Symbol from Symbol to Symbol G), Symbol (by Symbol from Symbol to Symbol), and Symbol (by Symbol from Symbol to Symbol), respectively. The more concentrated distribution of RapidPlan data points indicated an enhanced consistency of plan quality.
PACS number(s): 87.55.de; 87.55.dk