非均匀自制模体的临床可应用性实验分析

目的 对自制等效于人体多种组织密度模体，进行临床质控可应用性实验分析。方法 自制密度接近骨骼、肺、空腔及软组织的模体材料，并组合制作非均匀验证模体，然后对器官等效材料的电子密度进行比较。选用本科收治的10例肺癌患者，分别在该自制模体和固体水模体上进行调强计划剂量验证，比较2种模体在剂量验证领域的特点，并分析自制模体在TPS上的计算值与实测值的剂量学差异，采用SPSS 21.0软件进行统计分析。结果 使用自制模体和固体水模体进行剂量验证，γ通过率（3 mm /3%）均在90%以上。应用自制模体进行剂量验证的测量值，比使用固体水模体时偏大，测量值最大偏差为11.5%。2种模体间的剂量验证γ通过率AD组和RD组差异无统计学意义（P > 0.05）。结论 自制模体符合临床应用的精度要求，可应用在放射治疗计划验证。

Experimental analysis of clinical applicability of homemade in homogeneous phantom

Objective To conduct experimental analysis of clinical applicability of a homemade phantom which is equivalent to multiple tissue densities of human body.Methods Materials with densities close to bone, lung, cavity, and soft tissue were manufactured and combined to obtain a homemade in homogeneous phantom. The electron density of equivalent materials was compared with the organs. Ten lung cancer patients in our department were recruited for dose verification of intensity modulated radiation therapy in the homemade phantom and solid-water phantom. The two phantoms were compared for characteristics in dose verification, and the dosimetric differences of the homemade phantom between the calculated values on treatment planning systemand measured values were statistically analyzed by SPSS 21.0 software.Results In the dose verification, the gamma pass rates (3 mm/3%) were more than 90% using both the homemade phantom and solid-water phantom. The measured values in homemade phantom were larger than those in solid-water phantom, and the maximum deviation was 11.5%. The AD and RD values of gamma pass rate in dose verification showed no significant differences between the two phantoms (P > 0.05).Conclusion The homemade phantom meets the accuracy requirement of clinical application and can be used in dose verification of intensity modulated radiation therapy plan.