Nishiyama Yoshihiro, Yamamoto Yuka, Kimura Naruhide, Ishikawa Shinya, Sasakawa Yasuhiro, Ohkawa Motoomi
Department of Radiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, Japan.
Ann Nucl Med. 2008 May;22(4):245-50. doi: 10.1007/s12149-007-0103-2. Epub 2008 Jun 6.
The objective of this study was to retrospectively evaluate whether delayed additional F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging can improve the certainty of this modality in evaluating lymph node metastasis in patients with non-small-cell lung cancer (NSCLC).
Eighty-three patients with NSCLC were examined. FDG-PET imaging (whole body) was performed at 1-h (early) post-FDG injection and repeated 2 h (delayed) after injection only in the thoracic area. The PET images were evaluated qualitatively for regions of focally increased metabolism. If a lymph node was visible on the PET image, the semi-quantitative analysis using the standardized uptake value (SUV) was determined for both early and delayed images (SUV(early) and SUV(delayed), respectively). Retention index (RI) was then calculated on the basis of the following equation: (SUV(delayed) - SUV(early)) x 100/SUV(early). The RI value of more than 0% was taken to be the PET criterion for malignancy.
For early and delayed PET, sensitivities for lymph node staging were 54% and 62%, respectively, specificities were 89% for both, and accuracies were 78% and 81%, respectively. The results of combined delayed PET and RI showed a sensitivity of 62%, specificity of 96%, and accuracy of 86%.
Dual-time-point FDG-PET (combined delayed PET and RI) showed better (although not statistically significant) specificity, positive predictive value, and accuracy than early or delayed PET alone for lymph node staging in NSCLC.
本研究的目的是回顾性评估延迟进行额外的F-18-氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）成像是否能提高该方法在评估非小细胞肺癌（NSCLC）患者淋巴结转移方面的准确性。
对83例NSCLC患者进行了检查。在注射FDG后1小时（早期）进行FDG-PET全身成像，仅在胸部区域于注射后2小时（延迟）重复成像。对PET图像上代谢局部增加的区域进行定性评估。如果PET图像上可见淋巴结，则分别对早期和延迟图像（分别为SUV(早期)和SUV(延迟)）进行标准化摄取值（SUV）的半定量分析。然后根据以下公式计算滞留指数（RI）：(SUV(延迟) - SUV(早期))×100/SUV(早期)。RI值大于0%被视为PET诊断恶性肿瘤的标准。
对于早期和延迟PET，淋巴结分期的敏感性分别为54%和62%，特异性均为89%，准确性分别为78%和81%。延迟PET与RI联合分析的结果显示，敏感性为62%，特异性为96%，准确性为86%。
对于NSCLC的淋巴结分期，双时相FDG-PET（延迟PET与RI联合）比单独的早期或延迟PET显示出更好（尽管无统计学显著性）的特异性、阳性预测值和准确性。
