Correlation of Apparent Diffusion Coefficient with Histologic Type and Grade 
of Lung Cancer

Abstract

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). Conclusion 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.

Keywords

• Lung neoplasms
• Diffusion-weighted imaging
• Apparent diffusion coefficient
• Magnetic resonance imaging