Regional Center of Nuclear Medicine, University of Pisa Medical School, Italy.
AJR Am J Roentgenol. 2011 Jul;197(1):209-16. doi: 10.2214/AJR.10.5342.
Our purpose was to determine the diagnostic performance of 18F-FDG PET/CT for characterizing adrenal masses in patients with cancer, combining standardized uptake value (SUV) and CT histogram analysis.
A total of 117 adrenal masses in 93 patients with cancer (61 men and 32 women; mean [± SD] age, 67.2 ± 10.3 years; range, 38-84 years) were evaluated with FDG PET/CT. Of the 117 lesions, 42 were malignant according to histopathologic analysis or size change, whereas 75 were benign on the basis of stability for 6 months. Size, mean attenuation value, percentage of negative pixels at CT histogram analysis, maximum SUV (SUV(max)), and average SUV were calculated for each adrenal lesion. Moreover, FDG adrenal uptake was compared with radioactivity of the aorta, liver, and spleen by calculating the SUV ratios of adrenal lesion to aorta, adrenal lesion to liver, and adrenal lesion to spleen. PET/CT value was assessed by using independent t tests and receiving operating characteristic (ROC) analysis.
There was a statistically significant difference in size, attenuation value, percentage of negative pixels, and SUV between benign and malignant masses. All malignant lesions showed FDG activity higher than that in liver, spleen, and aorta, with SUV(max) greater than 2.8 in all cases, whereas with the CT histogram analysis, all lesions with a percentage of negative pixels higher than 10% were benign. Combined SUV and CT histogram analysis yielded 100% sensitivity, 97.3% specificity, 95.7% positive predictive value, and 100% negative predictive value. At ROC analysis, combined SUV and CT histogram analysis (area under the ROC curve [AUC], 0.996) was more accurate than simple SUV(max) analysis (AUC, 0.961) and the combination of SUV(max) and attenuation value (AUC, 0.987).
The combination of SUV and CT histogram analysis allowed us to significantly improve the PET/CT diagnostic accuracy for characterizing adrenal lesions, leading to a significant reduction in the number of false-positive cases.
本研究旨在通过结合标准化摄取值（SUV）和 CT 直方图分析，评估 18F-FDG PET/CT 对癌症患者肾上腺肿块的诊断性能。
对 93 例癌症患者（61 名男性，32 名女性；平均[±标准差]年龄 67.2±10.3 岁；范围 38-84 岁）的 117 个肾上腺肿块进行了 FDG PET/CT 评估。根据组织病理学分析或大小变化，42 个病变为恶性，而 75 个病变根据 6 个月的稳定性判断为良性。计算每个肾上腺病变的大小、平均衰减值、CT 直方图分析中阴性像素的百分比、最大 SUV（SUV(max)）和平均 SUV。此外，通过计算肾上腺病变与主动脉、肝脏和脾脏的 SUV 比值，比较了 FDG 肾上腺摄取与放射性示踪剂的活性。使用独立 t 检验和接收者操作特征（ROC）分析评估 PET/CT 值。
良性和恶性肿块之间的大小、衰减值、阴性像素百分比和 SUV 存在统计学差异。所有恶性病变均显示 FDG 活性高于肝脏、脾脏和主动脉，所有病例的 SUV(max)均大于 2.8，而 CT 直方图分析中，所有阴性像素百分比高于 10%的病变均为良性。SUV 和 CT 直方图联合分析的灵敏度为 100%，特异性为 97.3%，阳性预测值为 95.7%，阴性预测值为 100%。在 ROC 分析中，SUV 和 CT 直方图联合分析（ROC 曲线下面积[AUC]，0.996）比单纯 SUV(max)分析（AUC，0.961）和 SUV(max)与衰减值的联合分析（AUC，0.987）更准确。
SUV 和 CT 直方图分析的结合显著提高了 PET/CT 对肾上腺病变的诊断准确性，从而显著减少了假阳性病例的数量。
