18F-FDG PET-CT显像在胰腺转移癌中的应用价值

Value of 18F-FDG PET-CT imaging in the management of pancreatic metastasis

目的 分析胰腺转移癌的PET-CT表现,提高对该病变的检出率.方法 回顾性分析31例经临床确诊的胰腺转移癌的PET-CT图像,并与26例胰腺原发癌进行比较.由两位经验丰富的专科医师在融合图像上确定病灶所在位置,经过帧对帧的图像分析,确认病灶放射性摄取明显高于周围正常胰腺者为阳性.沿PET所示病灶边缘勾画感兴趣区,由工作站自动算出最大标准摄取值（SUVmax）,SUVmax＞ 2.5为阳性病灶.结果 31例胰腺转移癌的原发灶为肺癌22例,胃癌及结肠癌各2例,上颌窦癌、甲状腺癌、黑色素瘤、胆囊癌及肾癌各1例.21例（67.7％）为单发,10例（32.3％）为多发或弥漫性病灶.单发病灶中7例（33.3％）位于胰头颈部,14例（66.7％）位于胰体尾部.26例原发胰腺癌18例（69.2％）位于胰头颈部,8例（30.8％）位于胰体尾部.胰腺转移癌与原发癌的发生部位差异具有统计学意义（x2 =6.102,P=0.014）.CT平扫仅发现17例胰腺有病灶,呈结节状,略低密度,大部分病灶边界欠清晰.31例转移性胰腺癌PET显像均显示病灶,平均SUVmax为7.42±3.48,显著高于胰腺原发癌的5.39±1.71 （F=4.87,P=0.032）.此外,PET-CT同时发现30例有其他脏器或淋巴结转移.结论 18F-FDG PET-CT在检出并诊断胰腺转移癌中有毋庸置疑的优势.

Objective To investigate the features of PET-CT manifestation of pancreatic metastasis, and to improve its detection rate. Methods The PET-CT images of 31 cases of clinically diagnosed pancreatic metastases and 26 cases of primary pancreatic cancer were retrospectively evaluated. Two experienced specialists identified the lesion location in fused images. After frame by frame image analysis, the lesions with significantly increased radioactivity uptake were seen as positive, when compared with surrounding normal pancreatic tissue. The outline of regions of interest was drawn along the edge of the lesion shown in PET, and based on a semi-quantitative evaluation, the maximum standard uptake value （SUVmax） was calculated. If SUVmax 〉 2.5, it was considered as positive. Results Among the 31 cases with pancreatic metastasis, 22 cases of lung cancer, 2 cases of gastric cancer 2 cases of colon carcinoma, 1 case of maxillary sinus carcinoma, thyroid carcinoma, melanoma, renal cell carcinoma or gallbladder carcinoma were identified. Twenty-one cases （67.7%） were single, 10 cases （32.3%） were multiple or diffuse lesions. Among the single lesions, 7 （33.3%） were located in the pancreatic head and neck, 14 in pancreatic body and tail. Among the 26 cases of primary pancreatic carcinoma, 18 cases （69.2%） were located in the pancreatic head, 8 （30.8%） in the pancreatic body and taft. The sites of primary and metastatic pancreatic cancer were significantly different（X2 = 6. 012, P = 0. 014）. CT scan showed only 17 nodular lesions with relatively low density and less clear boundary. PET images showed lesions in 31 cases of metastatic pancreatic cancer, and the mean SUVmax was 7.42 ± 3.48, which was significantly higher than that in primary pancreatic cancer group （5.39 ± 1.71, F = 4.87, P = 0.032）. In addition, PET-CT identified 30 cases of other organs or lymph node metastasis. Conclusions PET-CT plays an important role in the diagnosis of metastatic pancreatic cancer.