^(18)F-FDG PET/CT偶发直结肠局灶性高代谢灶良恶性判断价值

The discrimination of incidental focal hypermetabolic colorectal lesions identified by ^(18)F-flurodeoxyglucose positron emission tomography

目的探讨PET/CT意外发现直结肠FDG局灶性高代谢灶的临床意义。方法回顾性分析34例PET/CT意外探测到直结肠局灶性高放射性摄取灶的病例,半定量分析局部病灶放射性摄取程度,均在1个月内行结肠镜检查,对表现为新生肿物病灶进行手术切除并做病理分析,将肠镜及病理结果作为金标准。所有临床资料及半定量分析数据汇总后行单因素方差分析。结果在所有34例结肠局灶性FDG高代谢病灶中,结肠镜及病理检查出恶性及癌前病变共22例,阳性预测值(PPV)为64.7%。其中8例为腺瘤,病灶SUVmax平均值为7.55±2.1,14例恶性病灶(9例腺癌,卵巢癌转移2例,间皮瘤转移2例,交界瘤转移1例),SUVmax平均值为7.62±4.87。结肠炎性改变4例(11.8%),SUVmax平均值为9.35±4.9,肠镜正常8例(23.5%),SUVmax平均值为7.4±1.75。癌前病变、恶性肿瘤、炎性病变及生理性摄取组间的单因素方差分析提示各组间无显著性差异,F=0.27,P=0.84,其中癌前病变组与恶性病灶组无显著性差异,P=0.968。结论 18F-FDG PET/CT偶然发现直结肠局灶性高摄取病灶中癌前病变和恶性病变阳性率很高,单纯依靠SUVmax,不能进行良恶性鉴别,因此进一步结肠镜检查是有临床意义的。

Objective Because colonic focal is predilection site of malignant tumors and inflammatory disease ,the pur-pose of this study was to investigate the discrimination of PET/CT detection of incidental colonic focal hypermetabolism . Methods 34 unexpected colonic focal uptake of 18 F-FDG localized by PET/CT were retrospectively analyzed ,and then semi-quantitatively analyzed the extent of radioactive uptake in colonic foci .After PET/CT ,the etiology of the findings was confirmed histological by surgery or endoscopic .All the data were assessed for statistical significance using one-way ANOVA .Results Among the 34 patients who underwent colonoscopy ,positive malignant or premalignant lesions were noted in 22 patients （64 .7% ） with the lesions coinciding with the location described in the PET/CT report .Adenomatous polyps were detected in 8 patients ,whereas in 14 patients ,malignant lesions were confirmed （adenocarcinoma n = 9 ,o-varian cancer metastatic ,n=2 ,Malignant Mesothelioma metastatic n=2 ,borderline tumor metastatic n=1） .The mean standardized uptake valuemax （SUVmax） for premalignant lesions was 7 .55 ± 2 .1 and for malignant lesions was 7 .62 ± 4.87 .4 patients （11 .8% ） colonic uptake was diagnosed as inflammatory ,the mean SUVmax was 9 .35 ± 4 .9 .8 patients （23 .5% ）had normal findings ,the mean SUVmax was 7 .4 ± 1 .75 .The difference in mean SUVmax between the premalig-nant adenomatous polyps and the malignant lesions was not statistically significant （ P =0 .968） .Conclusion Our study shows that a significant proportion of patients showing an incidental focal FDG uptake will harbor premalignant （adenoma-tous polyps） or malignant lesions ,and further evaluation with colonoscopy and biopsy is warranted in such cases .