鼻咽癌容积调强剂量验证与计划复杂性的相关性

目的:研究鼻咽癌容积调强剂量验证γ通过率与计划复杂性之间的相关性。 方法:选取106例鼻咽癌容积调强计划，采用二维电离室矩阵Matrixx进行剂量验证，比较测量的和计划的剂量分布，评价在不同标准（3%/3 mm、3%/2 mm、3%/1 mm、2%/2 mm）下的通过率。采用调强复杂性指数（MCS）定量评价计划的复杂性，并分析计划验证γ通过率与MCS间的关系。 结果:鼻咽癌容积调强计划在3%/3 m、3%/2 mm、3%/1 mm、2%/2 mm标准下的通过率分别为（98.49±0.95）%、（95.92±1.71）%、（89.74±2.44）%、（90.58±2.87）%。计划的平均MCS值为0.210±0.019，与通过率间（3%/3 m、3%/2 mm、3%/1 mm、2%/2 mm标准）的Pearson相关性系数分别为0.333（P<0.001）、0.303（P=0.002）、0.347（P<0.001）、0.267（P=0.006）。 结论:鼻咽癌容积调强计划验证γ通过率与MCS之间有相关性，但相关性较弱。

Correlation between dose verification and plan complexity of volumetric modulated arc therapy for nasopharyngeal carcinoma

Objective To study the correlations between gamma passing rate in dose verification and plan complexity of volumetric modulated arc therapy (VMAT) of nasopharyngeal carcinoma (NPC). Methods The VMAT plans of 106 NPC patients were selected. A two-dimensional ionization chamber array Matrixx was used for dose verification. The measured and planned dose distributions were compared and the gamma passing rates were evaluated under different criteria (3%/3 mm, 3%/2 mm, 3%/1 mm and 2%/2 mm). The modulation complexity score (MCS) of the treatment plan was calculated and used to quantitatively evaluate plan complexity. The correlation analysis between gamma passing rate and plan complexity was performed. Results If using the criteria of 3%/3 mm, 3%/2 mm, 3%/1 mm and 2%/2 mm, the gamma passing rate of VMAT plans was (98.49±0.95)%, (95.92±1.71)%, (89.74±2.44)% and (90.58±2.87)%, respectively. The mean MCS of plans was 0.210±0.019. Pearson’s correlation coefficient between the gamma passing rate (3%/3 mm, 3%/2 mm, 3%/1 mm and 2%/2 mm) and MCS were 0.333 (P<0.001), 0.303 (P=0.002), 0.347 (P<0.001) and 0.267 (P=0.006), respectively. Conclusion The gamma passing rate in the dose verification showed a weak correlation with MCS of VMAT of NPC.