18F-FDG与18F-FLT PET/CT延迟显像对肺结节诊断效能的评价

目的 通过对多中心、前瞻性研究中接受了18F-脱氧葡萄糖(FDG)与18F-脱氧胸腺嘧啶核苷(FLT)延迟显像病例的分析,探讨18F-FDG与18F-FLT延迟显像对肺结节诊断的效能.方法 6个PET/CT中心,从2006年1月至2007年6月,按照统一标准,采用同机型、同一扫描条件,开展了肺结节样病变18F-FLT和18F-FDG PET/CT显像的多中心临床研究.在经确诊的55例病例中,25例患者进行了18F-FLT显像和延迟显像,34例患者进行了18F-FDG延迟显像.按常规计算延迟显像时病灶最大标准摄取值(SUVmax)及与早期显像时SUVmax相比的变化率(△SUVmax).对照临床确诊结果分析其诊断效能.采用SPSS11.0软件进行统计学处理.结果 18F-FDG延迟显像患者中,6例肺癌中5例、12例结核中9例、16例炎症或其他良性结节中9例的SUVmax较早期相升高.18F-FLT延迟显像组中,7例肺癌中3例、8例结核中3例和10例其他良性病灶中2例的SUVmax上升.经分组统计分析,不同疾病组间18F-FDG延迟显像SUVmax和△SUVmax差异无统计学意义;18F-FLT延迟显像SUVmax和△SUVmax组间差异也无统计学意义.无论18F-FDG还是18F-FLT,延迟显像的诊断效能均不如早期相.无论早期还是延迟显像,单独18F-FDG或18F-FLT显像的诊断效能均不如二者联合应用.结论 18F-FDG和18F-FLT延迟显像的SUVmax变化规律性不强,不宜单独应用于肺结节的鉴别诊断.

The value of delayed PET/CT imaging using 18F-FDG and18 F-FLT in pulmonary nodules

Objective Based on a multicentre clinical trial, the value of dual-phase PET/CT imaging in differential diagnosis of pulmonary pathologies using "F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine (FLT) was investigated. Methods The multicentre clinical trial about 18F-FLT and 18F-FDG PET/CT imaging in lung nodules was carried out in six medical centers from January 2006 to June 2007 following the standardized protocols. Among 55 subjects successfully passed the data verification, 25 had delayed 18F-FLT PET/CT scanning and 34 18F-FDG at 120min post-injection. The maximum standardized uptake value (SUVmax), the difference of SUVmax between early and delay phase (ΔSUVmax) were calculated. The diagnostic performances of the dual phase imaging were analyzed in light of the confirmed diagnosis. SPSS 11.0 was used to analyse the data. Results In delayed 18F-FDG imaging, 5/6 tumors, 9/12 tuberculoses (TB) and 9/16 other benign lesions showed increased SUVmax. The increased SUVmax was noticed in 3/7 tumors, 3/8 TB and 2/10 others in delayed 18F-FLT imaging. Although a trend of increasing SUVmax in tumor in delayed phase was noted, there was no statistical difference in terms of FDG SUVmax among various patients groups, nor was there difference in ΔSUVmax. Difference among subgroups in FLT SUVmax was close to significance. The diagnostic performance of delayed imaging. 18F-FDG or 18F-FLT, was not as good as in early imaging, and provided little assistance to the differentiation of pulmonary pathologies. The diagnostic gains was far worse than that of combining dual-tracer PET/CT imaging. Conclusion The uptake of either 18FLT or 18F-FDG in delayed PET/CT imaging varied unpredictably thus was of limited value in the differential diagnosis of pulmonary lesions if used alone.