Diffusion-weighted MRI as a potential imaging biomarker reflecting the metastatic potential of upper urinary tract cancer

作者：Uchida Y; Yoshida S^*; Kobayashi S; Koga F; Ishioka J; Satoh S; Ishii C; Tanaka H; Matsuoka Y; Numao N; Saito K; Masuda H; Fujii Y; Kihara K

来源：British Journal of Radiology, 2014, 87(1042): 20130791.

DOI：10.1259/bjr.20130791

Objective: To evaluate the role of diffusion-weighted MRI (DW-MRI) as an imaging biomarker for upper urinary tract cancer (UUTC) that has already metastasized or will metastasize soon. %26lt;br%26gt;Methods: 61 patients clinically diagnosed with UUTC were prospectively enrolled in this study. All the patients underwent MRI, including DW-MRI, prior to any interventions. Correlations between apparent diffusion coefficient (ADC) and other clinicopathological variables, including metastasis-free survival, were analysed. %26lt;br%26gt;Results: Median follow-up period was 938 days. Of the 61 patients, 12 had any metastases at the initial diagnosis. 11 patients developed metastases during the follow-up period. These 23 patients were categorized as %26quot;Metastatic%26quot;. Of the remaining 38 patients, 35 with a follow-up period longer than 400 days were categorized as %26quot;Localized%26quot;. ADC was significantly lower in the Metastatic category than in the Localized (p = 0.0002) category. Multivariate analysis of pre-operative variables identified ADC (cut-off value, 1.08 x 10(-3) mm(2) s(-1)) and clinical T stage based on T-2 weighted MRI as an independent predictive factor of metastatic UUTC. 46 patients without any metastases during the initial diagnosis were stratified into a high-risk group (16 patients with low ADC and clinical T3-4) and a low-risk group (30 patients with high ADC or clinical Ta-2). The 3-year metastasis-free survivals were 45% and 93%, respectively. %26lt;br%26gt;Conclusion: In the current study, UUTC with lower ADC value is more likely to have metastatic potential. Incorporating ADC with clinical T stage helps to differentiate metastatic UUTC at the initial diagnosis. %26lt;br%26gt;Advances in knowledge: DW-MRI is a potential imaging biomarker reflecting metastatic propensity of UUTC.

• 出版日期2014-10