Abstract：Objective To analyze the correlation between the monitor units and pass rate of plan dose verification in the volumetric intensity modulated arc therapy (VMAT) plan. Methods VMAT plans for 20 patients with nasopharyngeal carcinoma (NPC) and 30 patients with cervical cancer who underwent radiotherapy at Liuzhou Workers' Hospital from January to October 2020 were retrospectively chosen. The Detector 1500 array and Octavius 4D phantom from German PTW company were used for dose measurement. The pass rates of dose verification of relevant plans were analyzed under the conditions of 3%/2 mm and 2%/2 mm. The correlation between the monitor units and pass rate of plan dose verification in VMAT plans was assessed by Pearson's bivariate correlation analysis. Results Under the condition of 3%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.873 (P<0.001), -0.800 (P<0.001), -0.781 (P<0.001), -0.493 (P=0.006) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Under the condition of 2%/2 mm, the correlation coefficients between the monitor units and gamma pass rate were -0.842 (P<0.001), -0.770 (P<0.001), -0.748 (P<0.001) and -0.531 (P=0.003) for NPC_1Arc, NPC_2Arc, NPC_1Arc+NPC_2Arc and Cervix_2Arc, respectively. Conclusions ignificant negative correlation can be observed between the monitor units and plan dose verification pass rate in VMAT plan.
Tan Junwen,Long Yusong,He Xiantao et al. Correlation between monitor units and pass rate of plan dose verification in VMAT plan for different cancers[J]. Chinese Journal of Radiation Oncology, 2023, 32(6): 546-550.
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