18F-氟乙酸联合18F-FDG PET/CT显像在肾肿瘤鉴别诊断中的价值

Value of 18F-flunoroacetate combined with 18F-fluorodeoxyglucose in differential diagnosis of renal masses

关键词:  18F-FAC  18F-FDG  肾占位  体层摄影术  X线计算机

Key words:  18F-FAC  18F-FDG  renal mass  tomography  X-ray computed

摘要:

目的　探讨¹⁸F-FDG联合¹⁸F-FAC PET/CT显像对肾血管平滑肌脂肪瘤（angiomyolipoma, AML）与肾细胞癌（renal cell carcinoma, RCC）鉴别诊断及RCC分级的价值。　方法　回顾性分析福建省立医院46例可疑肾肿瘤而行¹⁸F-FDG、¹⁸F-FAC双核素PET/CT显像患者资料。所有病例均经手术或穿刺活检证实。测量所有病灶的¹⁸F-FDG、¹⁸F-FAC PET/CT显像SUVmax值及CT平扫图像CT值。分析RCC和AML CT值、SUVmax值差异及不同级别RCC SUVmax值差异是否有统计学意义。　结果　所有AML病灶表现为¹⁸F-FAC高摄取，¹⁸F-FDG低摄取或无摄取。RCC病灶的SUVmax值为2.07±0.51，显著低于乏脂肪AML（4.25±0.60)，P<0.05。低级别RCC检出率¹⁸F-FAC显像为82.6%（19/23），显著高于¹⁸F-FDG显像的8.7%（2/23），P<0.05。¹⁸F-FDG PET/CT显像高级别RCC SUVmax值(3.21±0.79)明显高于低级别RCC(1.21±0.13)，P<0.05。　结论　¹⁸F-FAC可应用于AML与RCC的鉴别诊断。双核素PET/CT显像不仅可应用于肾肿瘤的鉴别诊断，还可用于肿瘤分级及预后判断。

Abstract:

Objective　 To investigate the metabolic characteristics of renal cell carcinoma (RCC) and angiomyolipoma (AML) with ¹⁸F-flunoroacetate(¹⁸F-FAC) and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG).　Methods　 A total of 46 patients with a renal mass underwent both whole body ¹⁸F-FDG and ¹⁸F-FAC PET/CT imaging. The PET results were correlated with the histological diagnosis. The differences in CT number and SUVmax between RCC and AML, as well as in SUVmax between low-grade RCC and high-grade RCC were compared. (2 test and t-test were used for statistical analysis.　Results　 All AMLs showed negative ¹⁸F-FDG but increased ¹⁸F-FAC metabolism. The mean ¹⁸F-FAC SUVmax of RCC was significantly lower than lipid-poor AML (2.07±0.51 vs. 4.25±0.60, P<0.05). Low-grade RCC were more likely to be detected by ¹⁸F-FAC（19/23, 82.6%） than ¹⁸F-FDG（2/23，8.7%) (χ²=13.4 , P<0.05）. ¹⁸F-FDG SUVmax was significantly greater in high-grade than low-grade clear cell RCC (3.21±0.79 vs. 1.21±0.13, t=2.6, P<0.05). High-grade RCC were more avid for ¹⁸F-FDG, whereas low-grade more for ¹⁸F-FAC.　Conclusion　¹⁸F-FAC PET/CT helps in differentiating lipid-poor renal AML from RCC. A combination examination with ¹⁸F-FAC and ¹⁸F-FDG shows excellent sensitivity in the detection of RCC and can additionally provide a hint toward the differentiation grade of RCC.