CAJ | 학술논문

目的比较基于三维CT (3DCT)和四维CT (4DCT)构建的胸段食管癌原发肿瘤计划靶体积(PTV)的位置及体积差异性.方法 43例胸段食管癌患者于同次CT模拟定位时序贯完成3DCT和4DCT扫描.通过4DCT获取自由呼吸状态下靶区中心点三维方向最大位移,依据靶区位移不均匀外扩获取PTV3D,常规外扩获取PTVconvPTV4D则通过4DCT的10个时相靶区融合获得.结果胸上、中、下段食管癌患者PTV3D和PTVconv与PTV4D中心点位置差异三维方向上中位数均＜0.3 cm,PTV4D/PTV3D分别为0.80、0.88、0.71,PTV4D/PTVconv分别为0.67、0.73、0.76(x2=-3.18、-2.98、-3.06,P=0.001、0.003、0.002).胸上、中、下段食管癌PTV3D与PTV4D靶区相似度中位数分别为0.87、0.90、0.81,PTVconv与PTV4D的分别为0.80、0.84、0.83(x2=-3.18、-2.98、-3.06,P=0.001、0.003、0.002).三组患者PTV3D及PTVconv对PTV4D的包含度差异均＜2％.胸上、中段食管癌PTV3D造成正常组织受照体积比PTVconv降低了11.81％、11.86％,胸下段食管癌增加了2.93％.结论对胸中上段食管癌3DCT不均匀外扩构建的PTV与4DCT构建的PTV符合度较好,对胸下段食管癌常规外扩构建的PTV与4DCT构建的PTV符合度相对较为理想.
목적 비교기우삼유CT (3DCT)화사유CT (4DCT)구건적흉단식관암원발종류계화파체적(PTV)적위치급체적차이성.방법 43례흉단식관암환자우동차CT모의정위시서관완성3DCT화4DCT소묘.통과4DCT획취자유호흡상태하파구중심점삼유방향최대위이,의거파구위이불균균외확획취PTV3D,상규외확획취PTVconvPTV4D칙통과4DCT적10개시상파구융합획득.결과 흉상、중、하단식관암환자PTV3D화PTVconv여PTV4D중심점위치차이삼유방향상중위수균＜0.3 cm,PTV4D/PTV3D분별위0.80、0.88、0.71,PTV4D/PTVconv분별위0.67、0.73、0.76(x2=-3.18、-2.98、-3.06,P=0.001、0.003、0.002).흉상、중、하단식관암PTV3D여PTV4D파구상사도중위수분별위0.87、0.90、0.81,PTVconv여PTV4D적분별위0.80、0.84、0.83(x2=-3.18、-2.98、-3.06,P=0.001、0.003、0.002).삼조환자PTV3D급PTVconv대PTV4D적포함도차이균＜2％.흉상、중단식관암PTV3D조성정상조직수조체적비PTVconv강저료11.81％、11.86％,흉하단식관암증가료2.93％.결론 대흉중상단식관암3DCT불균균외확구건적PTV여4DCT구건적PTV부합도교호,대흉하단식관암상규외확구건적PTV여4DCT구건적PTV부합도상대교위이상.
Objective To determine the centroid and volumetric differences between the planning target volumes (PTVs) for primary tumor based on four-dimensional computed tomography (3DCT) and four-dimensional computed tomography (4DCT) in the treatment of upper-thoracic,middle-thoracic,and lower-thoracic esophageal cancer (EC).Methods Forty-three patients with upper-thoracic,middlethoracic,and lower-thoracic ECs underwent 3DCT and 4DCT simulation scans in sequence during free breathing.The maximum motions of gross tumor volume (GTV) centroid position in 3D directions were obtained by 4DCT scans.PTV3D was obtained on 3DCT according to GTV motions in 3D directions measured on 4DCT;PTV was obtained on 3DCT using a 1.0 cm margin to CTV;PTV4D was obtained by fusion of 10 time phases of 4DCT images.Results Among the patients with upper-thoracic,middle-thoracic,and lowerthoracic ECs,the median centroid shifts between PTV3D and PTV4D and between PTV and PTV4D in the 3D directions were all less than 0.3 cm; the median ratios of PTV4D to PTV3D were 0.80,0.88,and 0.71,respectively,compared with 0.67,0.73,and 0.76 for median PTV4D/PTV ratios (xx2 ＝-3.18,P =0.001 ; x2 =-2.98,P =0.003 ; x2 =-3.06,P =0.002) ; the median dice similarity coefficient (DSC)between PTV3D and PTV4D were 0.87,0.90,and 0.81,respectively,compared with 0.80,0.84,and 0.83 for DSC between PTV and PTV4D (x2 ＝-3.18,P =0.001 ; x2 =-2.98,P =0.003 ; x2 =-3.06,P =0.002) ;the differences between the degree of inclusion (DI) of PTV4D in PTV3D and DI of PTV4D in PTV were all less than 2％.The patients with upper-thoracic and middle-thoracic ECs had the irradiated normal tissue volumes due to PTV3D decreased by 11.81％ and 11.86％,as compared with those due to PTV but the value was increased by 2.93％ for those with lower-thoracic EC.Conclusions For the patients with upper-thoracic and middle-thoracic EC,3DCT-based PTV using asymmetrical margins provides a good coverage of PTV4D; for the patients with lower-thoracic EC,3DCT-based PTV using conventional margins provides an ideal conformity with PTV4D.