摘要
目的:探讨宫颈癌在放疗中形态和体积变化的MRI表现及其临床意义。材料和方法:60例宫颈癌患者给予与3次放疗和4次MRI检查。MRI检查时间点为:①第1次放疗前MRI检查。②第1次放疗后2～2.5周进行第2次放疗(剂量20～25Gy)前进行第2次MRI检查。③第2次放疗后2～2.5周进行第3次放疗(剂量45～50Gy)前行第3次MRI检查。④第3次放疗后1～2月患者随访时进行第4次MRI检查。肿瘤形态分为规则形、分叶形和不规则形。肿瘤进行体积测量(分为ROI体积测量法和直径体积测量法)。ROI体积测量法:勾画MRI矢状面T2WI上肿瘤的ROI范围,利用公式计算肿瘤体积。直径体积测量法:测量MRI矢状面、横断面T2WI上肿瘤的3条最大径(d1,d2,d3),利用公式计算肿瘤体积。两种测量结果与肿瘤放疗后的衰退率进行相关性研究。结果:肿瘤的分叶形和不规则形数量在放疗中先增加后下降,两者形态在放疗前占总数68%,第1次放疗后占80%,第2次放疗后占72%,第3次放疗后占33%。ROI体积测量法和直径体积测量法在放疗前和第3次放疗后测量的肿瘤准确率具有显著相关性(分别为r1=0.87和r4=0.82),但两者在第1次放疗后和第2次放疗后测量的肿瘤准确率相关性差(分别为r2=0.17和r3=0.67)。与ROI体积测量法相比较,直径体积测量法上肿瘤体积较大,而衰退率呈“缓慢下降”
Objective: To assess the morphological and volume changes of response in cervical cancer during an ongoing course of radiation therapy(RT) and to determine the significance of the morphological and volume response characteristics to predict the response to radio-therapeutic measure. Materials and Methods: Serial MRI examinations were performed in 60 advanced cervical cancer patients. MRI was obtained at the start of RT, at 20～25Gy(2～2.5 weeks of RT), at 45～50Gy(4～5 weeks of RT), and 1～2 months post-RT. Tumor morphology was classified qualitatively as tumor with regular and well defined margin(round/oval with a well-demarcated smooth margin) vs lobulated vs irregular. Tumor volume was assessed in each serial MR examination independently by ROI volumetry and diameter volumetry. ROI volumetry was traced on the computer workstation with a trackball in each sagittal T2-weighted image and calculated by the summation of all tumor areas in each slice and multiplication by the slice profile. Diameter volumetry was to measure the largest three orthogonal tumor diameters in each orthogonal measurement plane and calculate as an ellipsoid(V=d1×d2×d3×/6). Serial tumor volume was compared between the two measurement methods. Results: Tumor morphology became increasingly irregular during RT. The proportion of lobulated and irregular tumors increased during RT and declined post-RT(68% pre-RT, 80% at 2～2.5 weeks of RT, 72% at 4～5 weeks of RT, 33% post-RT). Accordingly, ROI volumetry and diameter volumetry correlated well with pre-RT(r1=0.89) and post-RT(r4=0.80), but correlation was poor during RT(r2=0.17 at 2～2.5 weeks of RT, r3=0.69 at 4～5 weeks of RT). Conclusion: Cervical cancers regress in a non-uniform fashion during RT and undergo increasingly irregular shrinkage. Measurement with ROI volumetry techniques, which can optimally measure irregular volumes, provides better assessment of radiation response during treatment than diameter volumetry.
出处
《中国临床医学影像杂志》
CAS
2004年第7期391-395,共5页
Journal of China Clinic Medical Imaging
关键词
宫颈肿瘤
磁共振成像
cervix neoplasms
magnetic resonance imaging
