Department of Neurosurgery, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
J Nucl Med. 2012 Dec;53(12):1904-10. doi: 10.2967/jnumed.112.105544. Epub 2012 Oct 17.
3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) is a radiopharmaceutical depicting tumor cell proliferation with PET. In malignancies of the lung, breast, head and neck, digestive tract, brain, and other organs, quantitative assessment of (18)F-FLT targeting has been shown to correlate with the proliferation marker Ki-67 and with clinical outcome measures such as time to progression and overall survival (OS). The aim of this study was to assess various PET segmentation methods to estimate the proliferative volume (PV) and their prognostic value for OS in patients with suspected high-grade glioma.
Twenty-six consecutive patients underwent preoperative (18)F-FLT PET/CT and T1-weighted MRI of the brain after contrast application. The maximum standardized uptake value (SUV(max)) of all tumors was calculated, and 3 different segmentation methods for estimating the PV were used: the 50% isocontour of the SUV(max) signal for the PV(50%), the signal-to-background ratio (SBR) for an adaptive threshold delineation (PV(SBR)) method, and the iterative background-subtracted relative threshold level (RTL) method to estimate the PV(RTL). The prognostic value of the SUV(max) and the different PVs for OS were assessed.
Twenty-two patients had glioblastoma multiforme, 2 had anaplastic oligodendroglioma, 1 had anaplastic ependymoma, and 1 had anaplastic astrocytoma. The median OS was 397 d (95% confidence interval, 204-577); 19 patients died during the follow-up period. The PV(SBR) showed a significantly (P = 0.002) better association with OS than did SUV(max), PV(RTL), and PV(50%). Receiver-operating-characteristic analysis resulted in a threshold volume for the PV(SBR) of 11.4 cm(3), with a sensitivity and specificity of 70% and 83%, respectively, for the prediction of OS. Kaplan-Meier analyses showed a significant discrimination between short and long OS (P = 0.024, log rank) for this threshold.
The PV as determined by (18)F-FLT PET is associated with OS in high-grade malignant gliomas. The SBR method yielded the best results to predict short and long OS.
评估各种 PET 分割方法来估计疑似高级别脑胶质瘤患者的增殖体积（PV）及其对总生存期（OS）的预后价值。
26 例连续患者在对比增强后行术前（18）F-FLT PET/CT 和 T1 加权 MRI 脑部检查。计算所有肿瘤的最大标准化摄取值（SUV(max)），并使用 3 种不同的分割方法来估计 PV：SUV(max)信号的 50%等浓度曲线用于估计 PV(50%)，自适应阈值勾画的信号-背景比（SBR）用于估计 PV(SBR))方法，以及迭代背景减除相对阈值水平（RTL）方法用于估计 PV(RTL)。评估 SUV(max)和不同 PV 对 OS 的预后价值。
22 例患者为多形性胶质母细胞瘤，2 例为间变性少突胶质瘤，1 例为间变性室管膜瘤，1 例为间变性星形细胞瘤。中位 OS 为 397 d（95%置信区间，204-577）；19 例患者在随访期间死亡。PV(SBR)与 OS 的相关性明显优于 SUV(max)、PV(RTL)和 PV(50%)(P = 0.002)。受试者工作特征分析得出，PV(SBR)的阈值体积为 11.4 cm(3)，用于预测 OS 的敏感性和特异性分别为 70%和 83%。Kaplan-Meier 分析显示，该阈值对 OS 长短的判别具有显著差异（P = 0.024，对数秩检验）。
（18）F-FLT PET 确定的 PV 与高级别恶性脑胶质瘤的 OS 相关。SBR 方法在预测短和长 OS 方面效果最佳。
