基于EPID的鼻咽癌容积旋转调强放疗计划的三维剂量验证的研究

Three-dimensional dose verification study of volumetric modulated arc therapy radiotherapy for nasopharyngeal carcinoma based on EPID

目的利用基于电子射野影像装置(EPID)的EDose 5.0系统验证鼻咽癌(NPC)容积旋转调强放疗(VMAT)计划的三维剂量分布,探讨该系统用于鼻咽癌VMAT计划三维剂量验证的可行性。方法分别使用基于EPID的EDose 5.0、Delta^4和ArcCHECK三维剂量验证系统对随机选取的14例鼻咽癌VMAT计划进行验证测量,并在不同Gamma(γ)分析标准下,比较不同三维验证系统的验证通过率。结果当选取3%/3 mm标准时,基于EPID的EDose 5.0、Delta^4和ArcCHECK的γ平均通过率均大于95%,分别为(97.09±1.40)%、(96.24±1.52)%和(97.40±1.68)%,均满足计划验证要求;EDose 5.0与Delta^4和ArcCHECK验证通过率两两比较表明,当评价标准为3%/3 mm、3%/2 mm和2%/2 mm时,EDose 5.0与Delta^4和ArcCHECK的测量验证结果间差异无统计学意义(P>0.05)。结论基于EPID的EDose 5.0系统可以用于鼻咽癌VMAT计划的三维剂量验证。

Objective To verify the 3D dose distribution of the volumetric modulated arc therapy(VMAT) plan for nasopharyngeal carcinoma(NPC) by using the EDose 5.0 system based on the electronic portal imaging device(EPID),and to analyze the feasibility of the system for three-dimensional dose verification of nasopharyngeal carcinoma VMAT plan. Methods A total of 14 nasopharyngeal carcinoma VMAT plans were selected randomly.These plans were measured and verified by EPID-based EDose 5.0,Delta^4 and ArcCHECK three-dimensional dose verification systems,and the passing rates of different 3D verification systems were compared under different gamma(γ) analysis criteria. Results When the 3%/3 mm standard was selected,the average passing rate of γ based on EPID-based EDose 5.0,Delta^4 and ArcCHECK was greater than 95%. The specific measuring results of three-dimensional dose verification were(97.09±1.40)%,(96.24±1.52)% and (97.40±1.68)% respectively,which all met the planning verification requirements;When EDose 5.0 was compared with the verification rates of Delta^4 and ArcCHECK respectively under the criteria of 3%/3 mm,3%/2 mm and 2%/2 mm( P >0.05),the result showed that there was no significant difference between the measurement results of EDose 5.0 and of Delta^4 and ArcCHECK. Conclusion The EPID-based EDose 5.0 system can be used for three-dimensional dose verification of the VMAT plan for nasopharyngeal carcinoma.