Bertolaccini Luca, Viti Andrea, Lanzi Eleonora, Fortunato Mirella, Chauvie Stephane, Bianchi Andrea, Terzi Alberto
Division of Thoracic Surgery Unit, S. Croce e Carle Hospital, Via Michele Coppino 26, 12100, Cuneo, Italy,
Gen Thorac Cardiovasc Surg. 2014 Apr;62(4):228-33. doi: 10.1007/s11748-014-0374-1. Epub 2014 Jan 30.
(18)Fluorine-fluorodeoxyglucose positron emission tomography/computed tomography is not yet accepted as a standard pretreatment evaluation of thymic epithelial neoplasm (TEN). Statistical correlation between standardized uptake value of tumor/mediastinum ratio and patients' WHO risk class has been reported. PET metabolic tumor volume (MTV) and total glycolytic volume (TGV) have been reported as additional prognostic imaging biomarkers in several human tumors. Purpose of study was to establish whether MTV and TGV add prognostic information in TEN.
A retrospective dynamic cohort study of prospectively collected data (2006-2012) on 23 consecutive patients with pathologically proven TEN (no thymic carcinoma) was conducted. All patients underwent chest CT, and PET for staging. SUV T/M ratio, semi-quantitative and volumetric analyses of TEN were calculated. Patients were categorized according to WHO classification (low-risk and high-risk thymomas). Statistical analysis was performed with bootstrap method. Multi-collinearity was established using Pearson correlation coefficient. Cut-off point for TGV was compared using Mantel Cox log rank test.
SUV T/M ratio, MTV, and TGV correlate with low- and high-risk TEN. However, the statistical correlation between TGV and WHO classification (ρ = 0.897) was higher than SUV T/M ratio (ρ = 0.873). Since sample distributions were not uniformly smooth, only one cut-off value was identified: a TGV of 383 served as a cut-off value between low-risk and high-risk TEN.
TGV is a PET reproducible imaging marker in patients with TEN, provides prognostic information, and could be useful in pretreatment stratification of patients. Nevertheless, it needs validation in larger cohort studies.
氟-氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描尚未被接受为胸腺上皮肿瘤（TEN）的标准预处理评估方法。已有报道称肿瘤/纵隔标准化摄取值与患者的世界卫生组织（WHO）风险分级之间存在统计学相关性。在几种人类肿瘤中，PET代谢肿瘤体积（MTV）和总糖酵解体积（TGV）已被报道为额外的预后影像生物标志物。本研究的目的是确定MTV和TGV是否能为TEN增添预后信息。
对前瞻性收集的23例经病理证实为TEN（无胸腺癌）的连续患者（2006 - 2012年）的数据进行回顾性动态队列研究。所有患者均接受胸部CT和PET检查以进行分期。计算了TEN的SUV T/M比值、半定量分析和体积分析。患者根据WHO分类（低风险和高风险胸腺瘤）进行分类。采用自助法进行统计分析。使用Pearson相关系数建立多重共线性。使用Mantel Cox对数秩检验比较TGV的截断点。
SUV T/M比值、MTV和TGV与低风险和高风险TEN相关。然而，TGV与WHO分类之间的统计学相关性（ρ = 0.897）高于SUV T/M比值（ρ = 0.873）。由于样本分布并非均匀平滑，仅确定了一个截断值：TGV为383作为低风险和高风险TEN之间的截断值。
TGV是TEN患者中一种PET可重复的影像标志物，提供预后信息，并且可能有助于患者的预处理分层。然而，它需要在更大的队列研究中进行验证。
