Department of Diagnostic Radiology, University of Hong Kong, Queen Mary Hospital, Rm 406, Block K, 102 Pokfulam Rd, Hong Kong, China.
AJR Am J Roentgenol. 2012 Jul;199(1):169-74. doi: 10.2214/AJR.11.7336.
The purpose of this study was to quantitatively evaluate the role of intratumoral heterogeneity of (18)F-FDG uptake in characterizing nasopharyngeal carcinoma (NPC).
Forty consecutively registered patients with newly diagnosed NPC underwent PET/CT. The heterogeneity factor, defined as the derivative of a volume threshold function, was computed for each tumor. The relations between heterogeneity factor and maximum standardized uptake value (SUV(max)), tumor volume, and TNM category were determined by two-tailed Spearman correlation. Factors that potentially affect outcome determined by disease-free survival were studied by Kaplan-Meier analysis with a log-rank test for univariate analysis and the Cox proportional hazard model for multivariate analysis.
The heterogeneity factor ranged from -1.80 to -0.13 (mean, -0.40 [SD, 0.40]) and significantly correlated with SUV(max) (r = -0.372; p = 0.018), tumor volume (r = -0.983; p < 0.001), and T category (r = -0.457; p = 0.003) but not with N and M categories. There was a significant difference in heterogeneity factor between T1 and T2 tumors and T3 and T4 tumors (p = 0.012). The 2-year disease-free survival rate among the 38 patients was 67.4%. According to the results of Kaplan-Meier analysis with the log-rank test, heterogeneity factor and M category significantly affected disease-free survival. Patients with tumors that had a heterogeneity factor greater than -0.24 (less-heterogeneous group) (p = 0.0498) or M0 status (p < 0.001) had better disease-free survival rates. Multivariate analysis showed only M category to be an independent predictor of disease-free survival (p < 0.001).
The intratumoral heterogeneity of FDG uptake varies across NPC tumors, significantly correlates with tumor aggressiveness, and is predictive of patient outcome. These findings may be useful for characterizing NPC, predicting survival, and improving patient care.
本研究旨在定量评估（18）F-FDG 摄取的肿瘤内异质性在鼻咽癌（NPC）特征描述中的作用。
连续登记了 40 例初诊为 NPC 的患者，均行 PET/CT 检查。为每个肿瘤计算定义为体积阈值函数导数的异质性因子。通过双侧 Spearman 相关分析，确定异质性因子与最大标准化摄取值（SUV(max)）、肿瘤体积和 TNM 分期之间的关系。通过单因素分析的对数秩检验和多因素分析的 Cox 比例风险模型，研究了通过无病生存确定的潜在影响因素。
异质性因子范围为-1.80 至-0.13（平均值-0.40[标准差 0.40]），与 SUV(max)（r =-0.372；p =0.018）、肿瘤体积（r =-0.983；p <0.001）和 T 分期（r =-0.457；p =0.003）显著相关，但与 N 和 M 分期无关。T1 和 T2 肿瘤与 T3 和 T4 肿瘤之间的异质性因子存在显著差异（p =0.012）。38 例患者的 2 年无病生存率为 67.4%。根据对数秩检验的 Kaplan-Meier 分析结果，异质性因子和 M 分期显著影响无病生存率。异质性因子大于-0.24（异质性较小组）（p =0.0498）或 M0 状态（p <0.001）的患者无病生存率更高。多因素分析显示，只有 M 分期是无病生存的独立预测因素（p <0.001）。
FDG 摄取的肿瘤内异质性在 NPC 肿瘤之间存在差异，与肿瘤侵袭性显著相关，是患者预后的预测因素。这些发现可能有助于 NPC 的特征描述、生存预测和改善患者治疗。
