氟脱氧胸苷PET-CT勾划食管癌大体肿瘤生物靶区长度的病理对照研究

目的 应用术后病理作为对照判断氟脱氧胸苷(FLT)PET-CT检测食管癌大体肿瘤生物靶区长度的最佳方法 和最佳界值,并与FDG PET-CT、CT、食管钡餐和食管镜进行直接对照研究.方法 24例患者行FLT PET-CT检查,其中22例行FDG PET-CT检查对照,全部患者均常规行食管钡餐、食管镜检查并均接受食管癌根治切除术.FLT PET-CT长度采用肉眼法,记为L_(FLTvisual),和采用SUV 1.3、1.4、1.5以及SUV_(max)的20%、25%和30%分别记为L_(FLT1.3)、L_(FLT1.4)、L_(FLT1.5)、L_(FLT20%)、L_(FLT25%)、L_(FLT30%);FDG PET-CT长度采用肉眼法、SUV 2.5和SUV_(max)的40%分别记为L_(FDGviaual)、L_(FDG2.5)、L_(FDG40%).CT、食管钡餐和食管镜所测得病变长度分别记为L_(CT)、L_(Scopy)和L_(X-ray)分别与术后病理长度L_(Path)进行比较.结果 L_(Path)值为(4.90±2.14)cm,各检测方法 所得病变长度由小到大依次为L_(FDG40%)、L_(Scopy)、L_(X-ray)、L_(FLT1.5)、L_(CT)、L_(FLT30%)、L_(FLTvis)、L_(FLT1.4)、L_(FLT25%)、L_(FDG2.5)、L_(FDGvis)、L_(FLT1.3)、L_(FLT20%),均数分别为(3.85±1.52)、(4.46±2.23)、(4.63±2.37)、(4.64±2.38)、(4.69±1.85)、(4.75±2.19)、(4.85±2.33)、(4.87±2.35)、(5.05±2.20)、(5.08±2.19)、(5.10 ±2.22)、(5.21 ±2.40)、(5.53±2.17)cm,与L_(Path)的相关系数分别为0.91、0.93、0.88、0.95、0.90、0.81、0.96、0.96、0.80、0.99、0.99、0.95、0.79,P值均为0.000.L_(FLT1.4)和L_(FDG2.5)分别为最佳FLT PET-CT和FDG PET-CT长度,且L_(FDG2.5)与L_(FLT1.4)相似(t=1.23,P=0.232).结论 最接近食管癌病理长度的FLT PET-CT界值为SUV 1.4,而FDG PET-CT的为SUV 2.5,可作为客观和简便易行的半定量分析指标.

Pathological validation of FLT PET-CT in delineating the biological target length of gross tumor in esophageal carcinoma

Objective To establish a optimal method and threshold of 3-deoxy-3-fluorothymidine (FLT) PET-CT in delineating the biological target length of gross tumor in esophageal carcinoma, and to compare FLT PET-CT with other imaging modalities including esophagoseopy, esophagography, CT and flu-orodeoxyglucose (FDG) PET-CT. Methods Twenty-four patients with esophageal squamous cell carcinoma treated with radical surgery were enrolled. Before surgery, all the patients underwent FLT PET-CT, esepha-goscopy and esophagography. Twenty-two patients also received FDG PET-CT scan. Gross tumor volumes (GTV) were delineated using seven different threshold of FLT PET-CT: visual interpretation, standardized uptake value (SUV) 1.3, SUV 1.4, SUV 1.5, 20% of maximum standard uptake value (SUV_(max)), 25% SUV_(max), and 30% SUV_(max). Three different thresholds of FDG PET-CT were used, including visual interpre-tation, SUV 2.5, and 40% SUV_(max). The length of tumors on FLT PET-CT scan were measured and recorded as L_(FLTvis), L_(FLT1.3), L_(FLT1.4), L_(FLT1.5), L_(FLT20%), L_(FLT25%), and L_(FLT30%), respectively. The length of tumors on FDG PET-CT scan were recorded as L_(FDGvis), L_(FDG2.5), and L_(FDG40%), respectively. The length of tumors on CT, esophagography and esophagoscopy were recorded as L_(CT), L_(X-ray) and L_(Scopy). All of these results were com-pared with the length of gross tumor in the reseeted specimen measured by pathological examination (L_(Path)), Results The L_(Path) was (4.90±2.14) cm. The Length of tumors delineated by different methods, being from short to long, were L_(FDG40%), L_(Scopy), L_(X-ray),L_(FLT1.5),L_(CT),L_(FLT30%),L_(FLTvis),L_(FLT1.4),L_(FLT25%), L_(FDG2.5),L_(FDGvis),L_(FLT1.3),L_(FLT20%). The mean values were (3.85±1.52), (4.46±2.23), (4.63± 2.37), (4.64±2.38),(4.69± 1.85),(4.75±2.19) ,(4.85±2.33),(4.87±2.35),(5.05±2.20), (5.08± 2.19) ,(5.10±2.22), (5.21±2.40) and (5.53±2.17) cm,respectively. The correlation coefficients were 0.91,0.93,0.88, 0.95, 0.90, 0.81,0.96, 0.96, 0.80, 0.99, 0.99, 0.95 and 0. 79 , respective-ly. All the P values were 0. 000. L_(FLT1.4) of FLT PET-CT and L_(FDG2.5) of FDG PET-CT were found more ap-proximate to L_(Path). There was no significant difference between L_(FLT1.4) and L_(FDG2.5) (1= 1.23, P = 0.232), and the correlation coefficient was 0.96 (P = 0. 000). Conclusions Thresholds of SUV 1.4 on FLT PET-CT and SUV 2.5 on FDG PET-CT could optimally estimate the tumor length measured by pathological examina-tion, and could be objective and simple methods for semiquantitative analysis.