ABSTRACT
Objective To investigate the difference in the pass rate of intensity?modulated radiation therapy ( IMRT) planning in patients with different tumors and its value in determining pass rate thresholds. Methods A total of 35 verified IMRT plans for each of esophageal cancer, nasopharyngeal carcinoma, breast cancer, cervical cancer, and lung cancer were selected consecutively, and a one?way analysis of variance was used to investigate the difference in pass rate. A single pass rate threshold was used to test all IMRT plans, and the pass rate thresholds of IMRT plans for different tumors were calculated based on normal distribution law. Results There was a significant difference in the means between the 5 groups of data ( F=35. 83, P<0. 01) , and there was also a significant difference between any two groups ( P=0. 000) . There were statistically significant differences between nasopharyngeal carcinoma group and other four groups ( P=0. 000) . The difference was not only significant between the breast cancer group and the esophageal cancer group ( P=0. 001) , but also between the breast cancer group and the lung cancer group ( P=0. 033) . The calculated results of each threshold were 93. 37%, 89. 34%, 97. 68%, 95. 99%, and 95. 42%, respectively. Conclusions Different thresholds should be used for IMRT plans for different tumors, and the normal distribution law can be used to calculate the threshold.