Ozcan Kara Pelin, Kara Taylan, Kara Gedik Gonca, Kara Fatih, Sahin Ozlem, Ceylan Gunay Emel, Sari Oktay
Department of Nuclear Medicine, Selcuklu Medical Faculty, Selcuk University Konya, Turkey.
Nucl Med Commun. 2011 Feb;32(2):106-12. doi: 10.1097/MNM.0b013e32834199e7.
This retrospective study was designed to investigate the clinical role of whole-body positron emission tomography/computed tomography (PET/CT) by using 2-[18F]fluoro-2-deoxy-D-glucose (FDG), for the evaluation of adrenal lesions and to find the best index to distinguish benign from malignant lesions in various cancer patients.
A total of 81 patients (55 male and 26 female, age range: 31-81 years, mean: 61.5) who had confirmed primary malignancies (lung cancer in 47 patients, gastrointestinal malignancies in 13 patients, malignant melanoma in one patient, renal cell cancer in three patients, mesothelioma in two patients, breast carcinoma in nine patients, cervical cancer in one patient, ovarian cancer in two patients, pheochromocytoma in one patient, unknown primary in two patients) underwent PET/CT examinations for cancer screening, staging, restaging, and detection of suspected recurrence. Of the 81 patients, 104 adrenal lesions (34 benign and 70 malignant adrenal lesions) were shown by CT. On visual analysis of PET/CT imaging, adrenal uptake was based on a three-scale grading system. For final assessment standards of references for adrenal malignant lesions was based on biopsy (n=2), interval growth, or reduction after chemotherapy. An adrenal lesion, which remained unchanged on clinical and imaging follow-up of at least 7 months (mean follow-up time 19.31 months±6.46, range 7-30 months), was decided as a benign lesion.
In adrenal malignant lesions maximum standardized uptake value (SUVmax) (8.82±4.47) was higher than that of adrenal benign lesions (3.02±1.15, P<0.0001). In the differentiation of adrenal benign and malignant lesions, a CT threshold of 10 Hounsfield units corresponded to a sensitivity of 64.7%, specificity of 98.6%, and accuracy of 87.5%. An SUVmax cut-off value of 2.5 corresponded to a sensitivity of 100%, specificity of 38.2%, and accuracy of 80%. An SUVmax cut-off value of 4.2 corresponded to a sensitivity of 88.6%, specificity of 88.2%, and accuracy of 88.5%. The ratio of tumor SUVmax to liver SUVmean was 3.61±1.77 for adrenal malignant lesions whereas it was 1.20±0.38 for adrenal benign lesions (P<0.0001). T/L SUV ratio cut-off value of 1.8 corresponded to a sensitivity of 87%, specificity of 91%, and accuracy of 88.5%. T/L SUV ratio cut-off value of 1.68 corresponded to a sensitivity of 90%, specificity of 91.1%, and accuracy of 90.4%.
2-[18F]fluoro-2-deoxy-D-glucose-PET/CT improves the diagnostic accuracy in the differentiation of benign from malignant adrenal lesions in various cancer patients. Combined information obtained from PET/CT (SUVmax, T/L SUV ratio, visual analysis) and unenhanced CT (size, Hounsfield units measurement) is recommended for better differentiation.
本回顾性研究旨在探讨使用2-[18F]氟-2-脱氧-D-葡萄糖（FDG）的全身正电子发射断层扫描/计算机断层扫描（PET/CT）在评估肾上腺病变中的临床作用，并寻找区分各种癌症患者良性与恶性病变的最佳指标。
共有81例患者（55例男性，26例女性，年龄范围：31 - 81岁，平均61.5岁）确诊患有原发性恶性肿瘤（47例肺癌、13例胃肠道恶性肿瘤、1例恶性黑色素瘤、3例肾细胞癌、2例间皮瘤、9例乳腺癌、1例宫颈癌、2例卵巢癌、1例嗜铬细胞瘤、2例原发灶不明），接受PET/CT检查以进行癌症筛查、分期、再分期及检测疑似复发情况。81例患者中，CT显示104个肾上腺病变（34个良性肾上腺病变和70个恶性肾上腺病变）。在PET/CT影像的视觉分析中，肾上腺摄取基于三级分级系统。肾上腺恶性病变的最终评估参考标准基于活检（n = 2）、化疗后的间隔期生长或缩小情况。在至少7个月（平均随访时间19.31个月±6.46，范围7 - 30个月）的临床和影像随访中保持不变的肾上腺病变被判定为良性病变。
肾上腺恶性病变的最大标准化摄取值（SUVmax）（8.82±4.47）高于肾上腺良性病变（3.02±1.15，P < 0.0001）。在区分肾上腺良性与恶性病变时，10亨氏单位的CT阈值对应的敏感度为64.7%，特异度为98.6%，准确度为87.5%。SUVmax临界值为2.5时，敏感度为100%，特异度为38.2%，准确度为80%。SUVmax临界值为4.2时，敏感度为88.6%，特异度为88.2%，准确度为88.5%。肾上腺恶性病变的肿瘤SUVmax与肝脏SUVmean之比为3.61±1.77，而肾上腺良性病变为1.20±0.38（P < 0.0001）。肿瘤与肝脏SUV比值（T/L SUV）临界值为1.8时，敏感度为87%，特异度为91%，准确度为88.5%。T/L SUV比值临界值为1.68时，敏感度为90%，特异度为91.1%，准确度为90.4%。
2-[18F]氟-2-脱氧-D-葡萄糖-PET/CT提高了区分各种癌症患者肾上腺良性与恶性病变的诊断准确性。建议结合PET/CT（SUVmax、T/L SUV比值、视觉分析）和未增强CT（大小、亨氏单位测量）获得的信息以更好地区分。
