Liu Yiyan
Nuclear Medicine Service, Department of Radiology, University Hospital, UMDNJ, Newark, New Jersey 07103, USA.
Nucl Med Commun. 2011 Jul;32(7):554-62. doi: 10.1097/MNM.0b013e328345b984.
Thymic lesions may represent an unresolved diagnostic problem that often requires surgical procedure for an accurate diagnosis and staging. A noninvasive imaging study to determine the nature of thymic lesions would help to identify patients who are true candidates for surgery. Published preliminary clinical observations have suggested a role of fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography-computed tomography (PET-CT) in the characterization of thymic lesions. Benign uptake of the thymus on F-18 FDG PET-CT is seen in children and young adults, and may also indicate thymic hyperplasia in patients after chemotherapy or with Graves' disease. F-18 FDG PET-CT proves to be effective in differentiating thymic carcinoma from other entities within the thymus, and thymoma from thymic hyperplasia. The intensity of FDG uptake is useful for predicting the grade of malignancy in thymic epithelial tumors. However, the literature is equivocal with regard to the ability of F-18 FDG PET-CT to differentiate between invasive and noninvasive thymomas. Further larger studies are required to clarify the effectiveness and explore more clinical implications of F-18 FDG PET-CT on thymic lesions.
胸腺病变可能是一个尚未解决的诊断难题，通常需要通过手术来进行准确诊断和分期。一项用于确定胸腺病变性质的非侵入性影像学检查，将有助于识别真正适合手术的患者。已发表的初步临床观察结果表明，氟-18氟脱氧葡萄糖（F-18 FDG）正电子发射断层扫描-计算机断层扫描（PET-CT）在胸腺病变的特征描述中具有一定作用。儿童和年轻人的胸腺在F-18 FDG PET-CT上可出现良性摄取，这也可能提示化疗后患者或患有格雷夫斯病患者的胸腺增生。F-18 FDG PET-CT被证明在区分胸腺癌与胸腺内其他病变以及胸腺瘤与胸腺增生方面是有效的。FDG摄取强度有助于预测胸腺上皮肿瘤的恶性程度。然而，关于F-18 FDG PET-CT区分侵袭性和非侵袭性胸腺瘤的能力，文献中的观点并不一致。需要进一步开展更大规模的研究，以阐明F-18 FDG PET-CT对胸腺病变的有效性，并探索更多临床意义。
