Suga Kazuyoshi, Kawakami Yasuhiko, Hiyama Atsuto, Sugi Kazurou, Okabe Kazutomo, Matsumoto Tsuneo, Ueda Kazuhiro, Tanaka Nobuyuki, Matsunaga Naofumi
Department of Radiology, St. Hill Hospital, 1462-3 Nishikiwa, Ube, Yamaguchi 755-0151, Japan.
Ann Nucl Med. 2009 Aug;23(6):523-31. doi: 10.1007/s12149-009-0268-y. Epub 2009 May 15.
To clarify the difference of (18)F-FDG uptake kinetics between FDG-avid metastatic lymph nodes (LNs) in patients with non-small-cell lung cancer (NSCLC) and FDG-avid benign LNs associated with various etiologies on dual-time point PET/CT scan, and to determine the optimal parameter for differentiation.
The subjects were 134 FDG-avid metastatic LNs in 67 patients with NSCLC and 62 FDG-avid benign LNs in 61 patients with various lung disorders including NSCLC. PET/CT scan was performed at 2 time points (at 60 min and at 120 min) after intravenous injection of 4.4 MBq/kg (18)F-FDG. The maximum standardized uptake value (SUVmax) on early and delayed scans and the percent change of SUVmax (%DeltaSUVmax) were measured at each FDG-avid LN. The optimal parameter for differentiation was determined by the receiver-operating characteristic analysis.
Delayed SUVmax was increased compared with early SUVmax in 114 (85.0%) FDG-avid metastatic LNs and 42 (67.7%) FDG-avid benign LNs, with significant higher delayed SUVmax than early values (7.0 +/- 5.0 vs. 5.9 +/- 3.4; P < 0.0001, and 3.0 +/- 1.3 vs. 2.8 +/- 1.0; P < 0.05, respectively). Early and delayed SUVmax and %DeltaSUVmax in metastatic LNs were significantly higher than those in benign LNs (P < 0.0001). The optimal parameter for the differentiation was the combined use of early SUVmax > 3.0 or delayed SUVmax > 4.0, yielding sensitivity of 88.8%, specificity of 80.6%, accuracy of 86.2%, negative predictive value of 76.9%, and positive predictive value of 90.6%. It provided better results than the use of early SUVmax > 3.0 alone (P = 0.019) or the optimal parameter for %DeltaSUVmax (>5%) (P = 0.012). However, 12 (19.3%) benign LNs were indistinguishable from metastatic LNs.
Although dual-time point PET/CT scan enhances the difference of FDG uptake between FDG-avid metastatic and benign LNs and improves the differentiation when compared with a single scan, biopsy procedure may be still required for accurate assessment of LN status in patients with NSCLC and possible etiologies showing intensive FDG uptake in benign LNs.
明确非小细胞肺癌（NSCLC）患者中氟代脱氧葡萄糖（FDG）摄取活跃的转移性淋巴结（LNs）与因各种病因导致的FDG摄取活跃的良性LNs在双时相PET/CT扫描上的（18）F-FDG摄取动力学差异，并确定用于鉴别的最佳参数。
研究对象为67例NSCLC患者的134个FDG摄取活跃的转移性LNs以及61例包括NSCLC在内的各种肺部疾病患者的62个FDG摄取活跃的良性LNs。静脉注射4.4 MBq/kg（18）F-FDG后，在2个时间点（60分钟和120分钟）进行PET/CT扫描。测量每个FDG摄取活跃的LN在早期和延迟扫描时的最大标准化摄取值（SUVmax）以及SUVmax的变化百分比（%DeltaSUVmax）。通过受试者操作特征分析确定用于鉴别的最佳参数。
114个（85.0%）FDG摄取活跃的转移性LNs和42个（67.7%）FDG摄取活跃的良性LNs的延迟SUVmax较早期SUVmax升高，延迟SUVmax显著高于早期值（分别为7.0±5.0对5.9±3.4；P<0.0001，以及3.0±1.3对2.8±1.0；P<0.05）。转移性LNs的早期和延迟SUVmax以及%DeltaSUVmax显著高于良性LNs（P<0.0001）。用于鉴别的最佳参数是联合使用早期SUVmax>3.0或延迟SUVmax>4.0，其敏感性为88.8%，特异性为80.6%，准确性为86.2%，阴性预测值为76.9%，阳性预测值为90.6%。与单独使用早期SUVmax>3.0（P = 0.019）或%DeltaSUVmax的最佳参数（>5%）（P = 0.012）相比，该参数效果更好。然而，12个（19.3%）良性LNs与转移性LNs难以区分。
尽管双时相PET/CT扫描增强了FDG摄取活跃的转移性和良性LNs之间的FDG摄取差异，与单次扫描相比提高了鉴别能力，但对于NSCLC患者以及良性LNs中可能出现FDG摄取增强的病因，仍可能需要活检程序来准确评估LN状态。
