肺癌组织间插植放疗中两种驻留点优化方案的剂量分布比较研究

Comparative Study on Dose Distribution of Two Dwell Position Optimization Schemes in Interstitial Brachytherapy for Lung Cancer

目的比较肺癌组织间插植放疗计划中驻留点以线状排列方案与简化的驻留点设计优化方案的剂量分布的差别。方法针对14例铱源(^(192)Ir)后装近距离组织间插植照射患者,分别设计驻留点以线状排列的插植计划和简化的驻留点设计优化方案的插植计划;并比较两种计划的剂量分布。剂量参数包括:95%的CTV靶区受到的照射剂量D_(95)、D_(90)和D_(50);100%处方剂量所包绕的CTV体积V_(100)、V_(150)和V_(200);患侧肺和全肺1 cc所受照的剂量D_(1cc)、D_(5cc)和平均肺剂量;患侧肺和全肺体积V_(10)、V_(20)和V_(30);心脏平均剂量(MD)和D_(50);脊髓D_(1cc)、D_(5cc)和MD;肋骨D_(1cc)、D_(5cc)和MD。在SPSS 19.0统计软件中,采用Wilcoxon符号秩检验,以P<0.05为有统计学差异。结果两种优化方案的各参数差异不具有统计学意义(P>0.05)。结论从剂量参数比较上看,驻留点线状排列方案的插植计划相对于简化的驻留点设计优化方案插植计划并不具有明显的优势,简化的驻留点设计优化方案是一种合理可行的计划优化选择方案。

Objective To compare the dose distribution between dwell position line arrangement and the simplified dwell position optimization schemes in interstitial brachytherapy for lung tumor.Methods This study included fourteen patients who underwent192Ir source interstitial brachytherapy for lung cancer using two optimization schemes,dwell position line arrangement and the simplified dwell position optimization scheme.The dose distribution between these two schemes was compared.The specific dose parameters included the radiation dose covering95%(D95),90%(D90)and50%(D50)of clinical target volume(CTV).The CTV,covered by100%(V100),150%(V150)and200%(V200)of radiation dose;the radiation dose of ipsilateral lung and lungs received by1cc(D1cc),5cc(D5cc)and the mean lung dose(MLD);V10,V20and V30of ipsilateral lung and lungs;heart mean dose(MD)and D50;spinal cord D1cc,D5cc and MD;and rib D1cc,D5cc and MD.In SPSS19.0statistical software,Wilcoxon test was used to determine difference,with P<0.05considering statistically significant.Results There was no significant difference of dose parameters between two optimization schemes(P>0.05).Conclusion The dose distribution of dwell position line arrangement has no obvious advantage relative to the simplified dwell position optimization plan.The simplified dwell position optimization plan is a reasonable and feasible choice for interstitial brachytherapy.