Correlation of Apparent Diffusion Coefficient Value With Prognostic Parameters of Lung Cancer

Abstract
The purpose of this study was to correlate the apparent diffusion coefficient (ADC) value with prognostic parameters of lung cancer. Thirty-one patients diagnosed with lung cancer (22 men, 9 women; mean age, 57 years) underwent diffusion-weighted magnetic resonance imaging of the chest using echo-planar imaging sequence with b factors of 0, 300, and 600 s/mm. Apparent diffusion coefficient values were calculated and correlated with tumor grade and size as well as associated mediastinal lymph nodes. Institutional review board approval was obtained for this prospective study. The mean ADC value of small cell lung cancer (1.02 ± 0.30 × 10 mm/s) was significantly different (P = 0.025) from non-small cell lung cancer (1.39 ± 0.47 × 10 mm/s). There was a significant difference in the ADC value between poorly and well-differentiated to moderately differentiated lung cancer (P = 0.03) as well as between patients with N0 and N3 mediastinal lymphadenopathy (P = 0.043). The ADC value of lung cancer correlated with tumor grade (r = -0.481, P = 0.043) and metastatic mediastinal nodes (r = -0.422, P = 0.018). Apparent diffusion coefficient value of the lung cancer can be considered as a new prognostic parameter. Lower ADC value of the lung cancer is associated with higher pathological tumor grade and metastatic lymph nodes.