个性化3D打印头枕对头颈部肿瘤放疗计划剂量学的影响

Dosimetric effect of customized 3D-printed headrest in radiotherapy for head and neck tumor

目的:评估不同材料的3D打印头枕对头颈部肿瘤放疗计划剂量学的影响。通过比较放疗计划靶区剂量、均匀性指数(HI)、适形度指数(CI)、机器跳数(MU)、危及器官剂量等参数的差异,评估3D打印个性化头枕在计划中是否可被忽略。方法:选择10例头颈部肿瘤患者,包括5例鼻咽癌患者和5例其他头颈部肿瘤患者。使用医科达Monaco计划系统勾画头枕轮廓,并在相同的计算参数下,计算忽略头枕、普通头枕、10%填充的聚乳酸(PLA)和聚氨酯弹性体(TPU)材料3D打印头枕对应的放疗计划。记录靶区剂量、危及器官剂量和MU等结果,并进行统计学分析。结果:在D_(95)、D_(5)、D_(mean)、HI、CI、MU、危及器官剂量(脊髓最大剂量)等参数上,忽略头枕、普通头枕、PLA和TPU材料3D打印头枕4组数据之间均无统计学意义(P>0.05)。在考虑头枕存在的情况下,对于鼻咽癌和其他头颈部肿瘤的分析结果显示,CI有统计学意义(P<0.05)。结论:在计划设计阶段,可以忽略3D打印个性化头枕的存在,但考虑到头枕的存在会降低放疗计划的MU。在考虑头枕的情况下,其他头颈部肿瘤患者的CI平均值显著高于鼻咽癌患者。

Objective To evaluate the dosimetric effect of three-dimensional(3D)printed headrests made of different materials in radiotherapy for head and neck tumor,and to evaluate whether the existence of customized 3D-printed headrest can be neglected during planning phase by comparing differences in target area doses,homogeneity index(HI),conformity index(CI),monitor units(MU),and organ-at-risk(OAR)dose.Methods Ten patients with head and neck tumors,including 5 cases with nasopharyngeal carcinoma and 5 with other head and neck tumors,were enrolled.The headrest contours were outlined using Monaco treatment planning system,and with the same calculation parameters,treatment plans were generated for scenarios without a headrest,with a standard headrest,and with 3D-printed headrests made of 10%filled polylactic acid and thermoplastic polyurethane.The target area doses,OAR dose,MU,and other results were recorded and subjected to statistical analysis.Results No significant differences were observed among the 4 groups(ignoring headrest,standard headrest,3D-printed headrests with 10%filled polylactic acid and thermoplastic polyurethane)in parameters such as D_(95),D_(5),D_(mean),HI,CI,MU,and OAR dose(the maximum dose to the spinal cord)(P>0.05).Considering the presence of the headrest,significant differences were found in CI for nasopharyngeal carcinoma and other head and neck tumors(P<0.05).Conclusion During the planning phase,the existence of customized 3D-printed headrest can be ignored,but it should be noted that the presence of a headrest may reduce the MU in radiotherapy plans.When considering the headrest,the average CI of patients with other head and neck tumors is significantly higher than that with nasopharyngeal carcinoma.