CAJ | 학술논문

目的探讨CT模拟图像引导下宫颈癌三维腔内放疗实施的可行性及意义.方法对12例根治性放疗宫颈癌患者的55次腔内施源器置入CT图像,分别设计二维、三维计划,并行配对t检验、Wilcoxon符号秩检验、Pearson相关分析、Spearman相关分析.结果三维计划双侧A点剂量、D90、V100、CI、CI’均高于二维(P =0.015、0.016、0.000、0.000、0.000),三维计划的膀胱、直肠点剂量及直肠D2cm3略高于二维计划,但热点剂量明显减少.两组计划的膀胱、乙状结肠、小肠D2cm3相近(P=0.140、0.123、0.214).膀胱D2cm3明显高于膀胱点剂量(P =0.000).乙状结肠D2cm3较直肠D2cm3与直肠最高3点剂量平均值更相关(r =0.314、0.63,P=0.000、0.000).V100与高危CTV体积呈线性关系(r =0.981,P=0.000).膀胱D2cm3在膀胱体积＞80 cm3后达430 cGy以上,小肠D2cm3在膀胱体积＜ 115 cm3内变化不明显,一旦超过明显下降.结论 CT引导下宫颈癌三维腔内放疗较传统二维腔内放疗显著增加了靶区覆盖率、提高了适形度,但未明显增加OAR剂量且能及时发现减少OAR热点剂量.点剂量评估并不准确.可以通过膀胱体积调控膀胱、直肠、小肠剂量.
목적 탐토CT모의도상인도하궁경암삼유강내방료실시적가행성급의의.방법 대12례근치성방료궁경암환자적55차강내시원기치입CT도상,분별설계이유、삼유계화,병행배대t검험、Wilcoxon부호질검험、Pearson상관분석、Spearman상관분석.결과 삼유계화쌍측A점제량、D90、V100、CI、CI’균고우이유(P =0.015、0.016、0.000、0.000、0.000),삼유계화적방광、직장점제량급직장D2cm3략고우이유계화,단열점제량명현감소.량조계화적방광、을상결장、소장D2cm3상근(P=0.140、0.123、0.214).방광D2cm3명현고우방광점제량(P =0.000).을상결장D2cm3교직장D2cm3여직장최고3점제량평균치경상관(r =0.314、0.63,P=0.000、0.000).V100여고위CTV체적정선성관계(r =0.981,P=0.000).방광D2cm3재방광체적＞80 cm3후체430 cGy이상,소장D2cm3재방광체적＜ 115 cm3내변화불명현,일단초과명현하강.결론 CT인도하궁경암삼유강내방료교전통이유강내방료현저증가료파구복개솔、제고료괄형도,단미명현증가OAR제량차능급시발현감소OAR열점제량.점제량평고병불준학.가이통과방광체적조공방광、직장、소장제량.
Objective To evaluate the feasibility and significance of CT image-based threedimensional (3D) brachytherapy for cervical cancer.Methods Three-dimensional (3D) plan and twodimensional (2D) plan were designed for 55 CT images of brachytherapy from 12 cervical cancer patients who received radical radiotherapy in 2013.Dosimetric comparison was performed between the 3D plan and 2D plan,and paired t-test,Wilcoxon signed rank test,Pearson correlation analysis,and Spearman correlation analysis were performed.Results A point dose,D90,V100,CI,and CI' in 3D plan were higher than those in 2D plan (P=0.015,0.016,0.000,0.000,0.000).Bladder point dose,rectal point dose,and rectal D2 cm3 in 3D plan were slightly higher than those in 2D plan,but hot spot dose was significantly reduced in 3D plan (P =0.140,0.123,0.214).Bladder D2cm3 was significantly higher than bladder point dose (P =0.000).Sigmoid colon D2cm3 was more correlated with the average doses of the three highest rectal points than rectal D2 cm3 (r =0.314,0.630,P =0.000,0.000).V100 showed a linear relationship with high-risk CTV (r =0.981,P =0.000).Bladder D2cm3 was higher than 430 cGy when the bladder volume was more than 80 cm3 ;small intestinal D2 cm3 did not change significantly when the bladder volume was less than 115 cm3,but decreased significantly once the volume exceeded the value.Conclusions Compared with the traditional 2D plan,the 3D plan for CT image-based cervical cancer brachytherapy significantly increases the target coverage and conformity index,but does not significantly increase the doses to organs at risk.Point dose evaluation is confirmed to be inaccurate.The doses to the bladder,rectum,and small intestine can be adjusted by controlling the bladder volume.