Guo Chuangen, Zhuge Xiaoling, Chen Xiao, Wang Zhongqiu, Xiao Wenbo, Wang Qidong
Department of Radiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China.
Department of Laboratory of Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China.
Oncol Lett. 2017 Jun;13(6):4141-4146. doi: 10.3892/ol.2017.6029. Epub 2017 Apr 11.
The present study aimed to investigate the value of diffusion-weighted magnetic resonance imaging (DWI) in the grading of well-differentiated pancreatic neuroendocrine tumors (PanNETs). A total of 44 patients with histologically proven well-differentiated PanNET [grade 1 (G1) and grade 2 (G2) according to the World Health Organization (WHO) criteria] underwent pretreatment magnetic resonance imaging (MRI), which was retrospectively analyzed. The location, size, cystic or solid appearance, boundary, presence or absence of tumor contrast enhancement, and MRI signal of the tumor were assessed. Apparent diffusion coefficients (ADCs) within the primary tumor were measured on ADC maps. Receiver operating characteristic curves were used to determine ADC cut-off values and the sensitivity and specificity of the grade prediction. Spearman's rank correlation was utilized to probe the association between ADC value and PanNET grade or pathological parameters. G1 tumors exhibited a well-circumscribed border more often than G2 tumors. No marked differences were observed between PanNET G1 and PanNET G2 for cystic or solid appearance, enhancement, and T1- and T2-weighted imaging signals. Marked hyperintensities were more common in PanNET G2 tumors than in PanNET G1 tumors (P<0.01). The mean ADC values were statistically different between the normal pancreas and G1 and G2 tumors (P<0.01), and between PanNET G1 and PanNET G2 (P<0.05). Correlation analysis showed that ADC value was negatively correlated with PanNET grade, mitotic count and Ki-67 proliferation index (P<0.05). The cut-off ADC value was 0.930×10 mm/sec, which identified G2 tumors with 82.4% sensitivity and 79.5% selectivity. ADC value therefore represents a non-invasive and valuable imaging parameter in predicting the WHO grade of tumors in well-differentiated PanNET.
本研究旨在探讨扩散加权磁共振成像（DWI）在高分化胰腺神经内分泌肿瘤（PanNETs）分级中的价值。共有44例经组织学证实为高分化PanNET的患者（根据世界卫生组织（WHO）标准分为1级（G1）和2级（G2））接受了治疗前磁共振成像（MRI）检查，并对其进行回顾性分析。评估肿瘤的位置、大小、囊实性表现、边界、有无肿瘤强化以及MRI信号。在ADC图上测量原发肿瘤内的表观扩散系数（ADC）。采用受试者操作特征曲线确定ADC临界值以及分级预测的敏感性和特异性。利用Spearman等级相关性分析探讨ADC值与PanNET分级或病理参数之间的关联。G1肿瘤比G2肿瘤更常表现为边界清晰。PanNET G1和PanNET G2在囊实性表现、强化以及T1加权和T2加权成像信号方面未观察到明显差异。PanNET G2肿瘤中明显高信号比PanNET G1肿瘤更常见（P<0.01）。正常胰腺与G1和G2肿瘤之间的平均ADC值存在统计学差异（P< 0.01），PanNET G1和PanNET G2之间也存在统计学差异（P<0.05）。相关性分析表明，ADC值与PanNET分级、有丝分裂计数和Ki-67增殖指数呈负相关（P<0.05）。ADC临界值为0.930×10⁻³mm²/sec，其识别G2肿瘤的敏感性为82.4%，特异性为79.5%。因此，ADC值是预测高分化PanNET肿瘤WHO分级的一种无创且有价值的成像参数。
