CAJ | 학술논문

目的探讨基于3D-CT轴位扫描所定义的计划靶区(PTVvector)与基于4D-CT定义的计划靶区(PTV4D)的位置和体积差异.方法适合三维适形放疗(3D-CRT)的非小细胞肺癌(NSCLC)患者共28例,其中,16例肿瘤位于肺上叶为肺上叶组,12例肿瘤位于肺中下叶为肺中下叶组,均于同次CT模拟定位时序贯完成胸部常规3D-CT轴位扫描和4D-CT扫描.基于3D-CT图像GTV及其运动矢量定义PTVvector:GTV外扩7 mm形成CTV,在CTV基础上依据4D-CT测得的肿瘤三维运动矢量均匀外扩形成ITVvector,然后再外扩3 mm,形成PTVvector;基于4D-CT图像各时相GTV融合定义PTV4D:10个时相的GTV分别外扩7 mm形成各时相的CTV,10个时相的CTV融合形成ITV4D,ITV4D外扩3 mm形成PTV4D.对比PTVvector和PTV4D靶区位置、体积及包含度差异,分析三维运动矢量和相关参数的相关性.结果肺上叶和肺中下叶两组肿瘤中心三维运动矢量中位数分别为2.8和7,0 mm,差异有统计学意义(z=-3.485,P<0.05).肺上叶组PTVvector和PTV4D中心点坐标仅在x轴上差异有统计学意义(z=-2.010,P<0.05),肺中下叶组两靶区中心点坐标仅在;轴上差异有统计学意义(z=-2.136,P<0.05).肺上叶组PTV4D与PTVvector比值的中位数为0.75,肺中下叶组为0.52,两比值与肿瘤三维运动矢量的相关性差异均有统计学意义(r=-0.638、-0.850,P<0.05).PTVvector与PTV4D彼此间包含度的中位数分别为66.39%和99.55%,两者与肿瘤的三维运动矢量相关性差异有统计学意义(r=-0.814、0.613,P<0.05).结论基于4D-CT定义的PTV4D明显小于基于3D-CT定义的PTVvector,两者的比值及相互包含度均与肿瘤三维运动矢量显著相关.
목적 탐토기우3D-CT축위소묘소정의적계화파구(PTVvector)여기우4D-CT정의적계화파구(PTV4D)적위치화체적차이.방법 괄합삼유괄형방료(3D-CRT)적비소세포폐암(NSCLC)환자공28례,기중,16례종류위우폐상협위폐상협조,12례종류위우폐중하협위폐중하협조,균우동차CT모의정위시서관완성흉부상규3D-CT축위소묘화4D-CT소묘.기우3D-CT도상GTV급기운동시량정의PTVvector:GTV외확7 mm형성CTV,재CTV기출상의거4D-CT측득적종류삼유운동시량균균외확형성ITVvector,연후재외확3 mm,형성PTVvector;기우4D-CT도상각시상GTV융합정의PTV4D:10개시상적GTV분별외확7 mm형성각시상적CTV,10개시상적CTV융합형성ITV4D,ITV4D외확3 mm형성PTV4D.대비PTVvector화PTV4D파구위치、체적급포함도차이,분석삼유운동시량화상관삼수적상관성.결과 폐상협화폐중하협량조종류중심삼유운동시량중위수분별위2.8화7,0 mm,차이유통계학의의(z=-3.485,P<0.05).폐상협조PTVvector화PTV4D중심점좌표부재x축상차이유통계학의의(z=-2.010,P<0.05),폐중하협조량파구중심점좌표부재;축상차이유통계학의의(z=-2.136,P<0.05).폐상협조PTV4D여PTVvector비치적중위수위0.75,폐중하협조위0.52,량비치여종류삼유운동시량적상관성차이균유통계학의의(r=-0.638、-0.850,P<0.05).PTVvector여PTV4D피차간포함도적중위수분별위66.39%화99.55%,량자여종류적삼유운동시량상관성차이유통계학의의(r=-0.814、0.613,P<0.05).결론 기우4D-CT정의적PTV4D명현소우기우3D-CT정의적PTVvector,량자적비치급상호포함도균여종류삼유운동시량현저상관.
Objecttve To compare the positional and volumetric differences of planning target volumes(PTVs)based on axial three-dimensional CT(3D-CT)and four-dimensional CT(4D-CT)for the primary tumor of non-small cell lung cancer(NSCLC).Methods Sixteen NSCLC patients with lesions located in the upper lobe and 12 patients with lesions in middle and lower lobes,totally 28 patients, initially underwent three-dimensional CT scans followed by 4D-CT scans of the thorax under normal free breathing.PTVvector was defined on gross tumor volume (GTV) contoured on 3D-CT and its motion vector. The clinical target volumes(CTVs)were created by adding 7 mm to GTVs,then, internal target volume (ITVs)were produced by enlarging CTVs isotropically based on the individually measured amount of motion in the 4D-CT,lastly,PTVs were created by adding 3 mm setup margin to ITVs. PTV4D was defined on the fusion of CTVs on all phases of the 4D data.The CTV wag generated by adding7 mm to the GTV on each phase.then,PIVs were produced by fusing CTVs on 10 phases and adding 3 mm setup margin.The position of the target center,the volume of target and the degree of inclusion(DI)were compared reciprocally between the PTVvector and the PTV 4D The difference of the position,volume and degree of inclusion of the targets between PTVvecter and PTV4D were compared,and the relevance between the relative characters of the targets and the three-dimensional vector was analyzed based on the groups of the patients. Results The median of the 3 D motion vector for the lesions in the upper lobe was 2.8 mm, significantly lower than that for the lesions in the middle and lower lobe ( 7.0 mm, z = - 3. 485, P < 0. 05 ). In the upper lobe group there was only significant spatial difference between the PTVvector and PTV4D targets in the center coordinate at the x axe (z = -2. 010, P < 0. 05 ), while in the middle and lower lobes there was only significant spatial difference between the PTVvector and PTV4D targets in the center coordinates at the z axe (z = -2. 136,P <0.05). The median of ratio of PTV4D and PTVvector, of the upper lobe group was 0. 75, significantly higher than that of the middle and lower lobes group (0. 52, z = - 2. 949, P < 0. 05 ).A significant correlation was found for the motion vector and the ratio of PTV and PTV4D in both groups ( r = - 0. 638, - 0. 850, P < 0. 05 ). For all patients, the median of D[ of PTV4D in PTVvector was 66. 39% ,while the median of DI of PTVvector, in PTV4D was 99. 55% , both showed a positive significant correlation with the motion vector (r = -0. 814,0. 613 ,P < 0. 05). Conclusions PTV4D defined based on 4D-CT simulation images is obviously less than PTV defined based on 3D-CT simulation images. The ratio and DI of both targets are related with the three-dimensional motion vector of the tumor.