Background and objective: The histologic type and grade of lung cancer are significant in assessing the biological behaviour, prognosis and therapeutic regimen. This study investigates the correlation of apparent diffusion coefficient (ADC) with histologic type and grade of lung cancer.
Methods: A total of 115 patients pathologically diagnosed with lung cancer were enrolled in this study. Magnetic resonance (MR)-DWI with a diffusion factor of 500 s/mm2 was performed and the ADC values of lesions were measured. The ADC values among the different histologic types and grades were compared with the values obtained using t-test and one-way ANOVA. The correlation between ADC values and the histologic grades was further evaluated with Spearman correlation coefficient.
Results: With a b value of 500 s/mm2, the ADC values significantly differed between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) (P = 0.017). The ADC values of SCLC were significantly different from those of squamous cell carcinoma and adenocarcinoma (P = 0.011, 0.001, respectively). A significant difference was observed in the ADC values among the different histologic grades of lung cancer (P = 0.003), and the ADC value was correlated with the histologic grades (rs = -0.272, P = 0.003).
Conclusions: ADC value is significant for judgement of histologic type and grade of lung cancer before surgical operation: SCLC has a low ADC value, and ADC value is low for the tumor with poorly-differentiated grade.
背景与目的: 肺癌的组织学类型和分化程度对于评估肿瘤的生物学行为、预后及选择治疗方式具有重要意义。本研究旨在探讨表观扩散系数（apparent diffusion coefficient, ADC）与肺癌组织学类型和分化程度的相关性。
方法: 符合纳入标准的连续肺癌患者115例，行DWI检查（b=500 s/mm2）并测量病变的ADC值，用t检验及单因素方差分析分析不同组织学类型及不同分化程度间ADC值的差异，用Spearman相关系数分析ADC值与不同分化程度之间的相关性。
结果: 小细胞肺癌（small cell lung cancer, SCLC）与非小细胞肺癌（non-small cell lung cancer, NSCLC）的ADC值差异有统计学意义（P=0.017），且SCLC与鳞癌、腺癌的ADC值差异均有统计学意义（P分别为0.011、0.001）。肺癌不同分化程度间的ADC值差异有统计学意义（P=0.003），且ADC值与病变不同分化程度存在相关性（rs=-0.272, P=0.003）。
结论: ADC值对术前判断肺癌的组织学类型及分化程度有一定意义：小细胞肺癌的ADC值低，分化程度低的肿瘤的ADC值低。