Department of Radiology, Stanford University School of Medicine, and Pediatric Radiology Section, Lucile Packard Children's Hospital, 725 Welch Rd, Stanford, CA 94305-5654, USA.
Radiology. 2012 Feb;262(2):613-22. doi: 10.1148/radiol.11110715. Epub 2011 Dec 12.
To evaluate the role of positron emission tomography (PET)/computed tomography (CT) in the differentiation of normal thymus from mediastinal lymphoma and lymphoma recurrence in pediatric patients.
The study was approved by the institutional review board, and informed consent was waived. The study was HIPAA compliant. Two hundred eighty-two fluorine 18 fluorodeoxyglucose PET/CT studies in 75 pediatric oncology patients were reviewed retrospectively. Patients were divided into four groups: anterior mediastinal lymphoma (group A, n=16), anterior mediastinal lymphoma with subsequent recurrence (group B, n=5), lymphoma outside the mediastinum (group C, n=16), and other malignant tumors outside the thymus (group D, n=38). Analyses included measurements of the maximum anteroposterior and transverse dimensions of the anterior mediastinal mass or thymus on axial CT images and measurements of maximum standardized uptake values of anterior mediastinal mass, thymus (SUVt), and bone marrow at the level of the fifth lumbar vertebra (SUVb) on PET images. Quantitative parameters were compared by using an analysis of variance test.
Mean prechemotherapy SUVt was 4.82 for group A, 8.45 for group B, 2.00 for group C, and 2.09 for group D. Mean postchemotherapy SUVt for group B was 4.74. Thymic rebound (mean SUVt, 2.89) was seen in 44% of patients at a mean interval of 10 months from the end of chemotherapy. The differences between prechemotherapy SUVt of mediastinal lymphoma and normal thymus and postchemotherapy SUVt of lymphoma recurrence and thymic rebound were highly significant (P<.001).
SUVt is a sensitive predictor for differentiation of normal thymus or thymic rebound from mediastinal lymphoma. SUVt of 3.4 or higher is a strong predictor of mediastinal lymphoma.
评估正电子发射断层扫描（PET）/计算机断层扫描（CT）在鉴别儿科患者正常胸腺与纵隔淋巴瘤及淋巴瘤复发中的作用。
本研究经机构审查委员会批准，豁免了知情同意。本研究符合 HIPAA 规定。回顾性分析了 75 例儿科肿瘤患者的 282 例氟 18 氟代脱氧葡萄糖 PET/CT 研究。患者分为 4 组：前纵隔淋巴瘤（A 组，n=16）、前纵隔淋巴瘤后继发复发（B 组，n=5）、纵隔外淋巴瘤（C 组，n=16）和胸腺外其他恶性肿瘤（D 组，n=38）。分析包括在轴位 CT 图像上测量前纵隔肿块或胸腺的最大前后径和横径，以及在 PET 图像上测量前纵隔肿块、胸腺（SUVt）和第 5 腰椎水平骨髓（SUVb）的最大标准化摄取值。采用方差分析比较定量参数。
A 组化疗前 SUVt 平均为 4.82，B 组为 8.45，C 组为 2.00，D 组为 2.09。B 组化疗后 SUVt 平均为 4.74。化疗结束后 10 个月左右，44%的患者出现胸腺反弹（平均 SUVt 为 2.89）。纵隔淋巴瘤化疗前 SUVt 与正常胸腺 SUVt 及淋巴瘤复发后 SUVt 与胸腺反弹之间的差异均有统计学意义（P＜.001）。
SUVt 是鉴别正常胸腺或胸腺反弹与纵隔淋巴瘤的敏感指标。SUVt 为 3.4 或更高是纵隔淋巴瘤的强预测指标。
