18F-FDG PET/CT显像SUVmax与嗜铬细胞瘤恶性程度的相关性探讨

目的 分析嗜铬细胞瘤18 F-FDG PET/CT显像SUVmax与血浆游离甲氧基肾上腺素(MN)、甲氧基去甲肾上腺素(NMN)及131I-间位碘代苄胍(MIBG) SPECT显像间的关系,探讨18F-FDG PET/CT在诊断嗜铬细胞瘤和预测嗜铬细胞瘤恶性程度中的价值.方法 采用回顾性研究方法,收集经18F-FDG PET/CT检查且手术病理证实为嗜铬细胞瘤的患者19例,按其生物学行为分为良性组(n=11)与恶性组(n=8),查询PET/CT检查前后血MN、NMN及131 I-MIBG SPECT的检查结果,利用SPSS 17.0软件行两独立样本t检验,并绘制ROC曲线,探讨嗜铬细胞瘤SUVmax的特点,比较分析各检查之间的关系.结果 (1)11例良性嗜铬细胞瘤(BPCC)与8例恶性嗜铬细胞瘤(MPCC)PET/CT显像均为阳性;MPCC的SUVmax(19.40±7.39)明显大于BPCC的SUVmax (7.44±4.47),t=-4.40,P＜0.01;用约登指数法,确定SUVmax=8.85为判断嗜铬细胞瘤良恶性的分界值,其灵敏度、特异性和准确性分别为8/8、81.8％(9/11)、89.5％ (17/19);异位嗜铬细胞瘤SUVmax为19.75±8.64,明显高于肾上腺嗜铬细胞瘤SUVmax (9.12±5.83),t=-3.18,P＜0.05;初发与复发的嗜铬细胞瘤SUVmax间差异无统计学意义(t=-1.68,P＞0.05).(2)MN阴性病例SUVmax( 13.57±8.61)明显高于MN阳性病例SUVmax (6.63±2.42),t =2.70,P＜0.05;NMN阴性与阳性的病例SUVmax间差异无统计学意义(t=-0.93,P＞0.05).(3)7例同期行18F-FDG PET/CT与131I-MIBG SPECT患者中,3例BPCC,其中2例MIBG显像阳性,4例MPCC MIBG显像均为阴性;7例PET/CT显像均为阳性.结论 对于血MN与MIBG检查为阴性、但临床疑为嗜铬细胞瘤患者,FDG PET/CT可作为辅助诊断手段,减少漏诊率.

Correlation between the degree of malignancy of pheochromocytoma and the maximum standardized uptake value measured by 18F-FDG PET/CT

Objective To analyze the correlation of lSF-FDG SUVmaxwith plasma free metaneph- rines （MN） , normetanephrine （ NMN ） and 131I-meta-iodobenzylguanidine （ MIBG ） scintigraphy, and to explore the role of is F-FDG lbET/CT in distinguishing between benign pheochromoeytoma （BPCC） and ma- lignant pheoehromocytoma （MPCC）. Methods 18F-FDG PET/CT, plasma MN and NMN, and 131I-MIBG SPECT were studied in 19 patients with pheochromocytoma confirmed by postoperative pathology, including 11 benign and 8 malignant cases. ROC curve was drawn, and ISF-FDG SUVmax of patients with MN （NMN） positive and negative results was compared using two independent sample t-test by SPSS 17.0. Results Both BPCC and MPCC showed positive findings on 18F-FDG PET/CT. SUVmax of MPCC （ 19.40 ±7.39） was significantly higher than that of BPCC （7.44 ±4.47 ; t = -4.40, P 〈0.01 ）. Using a cut-off value of 8.85 on the ROC curve for determining BPCC and MPCC, the sensitivity, specificity and accuracy was 8/8, 81.8% （9/11 ） and 89.5 % （ 17/19 ） , respectively. SUVmax of adrenal lesions （ 19.75 ±8.64） was signifi- cantly higher than that of extra-adrenal lesions （9.12 ± 5.83 ; t = - 3. 18, P 〈 0.05 ）. The difference of SUVmax between new and recurrent lesions was not significant （t = - 1.68, P 〉 0.05 ）. SUVmax of MN negative cases （ 13.57 ± 8.61 ） was significantly higher than that of MN positive cases （6.63 ± 2.42 ; t = 2.70, P 〈 O. 05）. The difference of SUVmax between NMN negative and positive cases was not significant （t = - O. 93, P 〉 O. 05）. Seven patients underwent 131I_MIBG SPECT, among which one case with BPCC and four cases with MPCC were negative. The is F-FDG PET/CT results were positive in all seven patients. Conclusions 18 F-FDG PET/CT can be used as a second-line diagnostic tool for patients with negative MN or indetermi- nate 131I-MIBG SPECT findings. The degree of FDG uptake has potential in the differentiation of benign from malignant pheochromocytoma.