Prognostic prediction of resectable colorectal liver metastasis using the apparent diffusion coefficient from diffusion‐weighted magnetic resonance imaging

AIM: Diffusion‐weighted magnetic resonance imaging (DWI‐MRI) is used to predict tumor malignancy. Here we explored the role of apparent diffusion coefficient (ADC) values in the treatment of patients with resectable colorectal liver metastasis (CRLM). METHODS: Magnetic resonance imaging (MRI) scans were conducted using a Signa HDe or Signa Explorer 1.5‐T scanner (GE Healthcare). ADC maps were calculated using DWI with b values of 0, 20, and 800 s/mm(2). We enrolled 60 patients who underwent upfront hepatic resection for CRLM and divided them into ADC‐high (n = 30) and ADC‐low (n = 30) groups. Clinicopathological variables of the groups were compared. Immunohistochemical analysis of HIF‐1α expression in tumor tissues was performed, and the relationship between the ADC value and HIF‐1α expression was evaluated. RESULTS: The disease‐free survival rate of the ADC‐low group was significantly lower than that of the ADC‐high group (P < .05). Univariate analysis revealed that tumor number (more than five), synchronous metastasis, and low ADC were prognostic factors. Multivariate analysis identified low ADC as an independent prognostic factor. Furthermore, the ADC‐low group more frequently expressed high levels of HIF‐1α than the ADC‐high group. CONCLUSION: Low ADC values were an independent prognostic factor of resectable CRLM and correlated with HIF‐1α expression.