Abstract
OBJECTIVE: To determine whether change in apparent diffusion coefficient value could predict early response to chemotherapy in breast cancer liver metastases. MATERIALS AND METHODS: We retrospectively studied 42 patients (86 lesions) with breast cancer liver metastases who had undergone conventional magnetic resonance imaging and diffusion-weighted imaging (b = 0.700 s/mm(2)) before and after chemotherapy. Maximum diameter and mean apparent diffusion coefficient value (×10(-3) mm(2)/s) of liver metastases from breast cancer were evaluated. The grouping reference was based on magnetic resonance imaging according to Response Evaluation Criteria in Solid Tumors (RECIST). Analysis of variance and receiver-operating characteristic analyses were performed. RESULTS: Eighty-six metastases were classified as 40 responders and 46 nonresponders. A statistically significant correlation was found between prechemotherapy and postchemotherapy apparent diffusion coefficient values in responders, which were 0.9 ± 0.16 × 10(-3) mm(2)/s, 1.05 ± 0.12 × 10(-3) mm(2)/s, 1.26 ± 0.12 × 10(-3) mm(2)/s, and 1.33 ± 0.87 × 10(-3) mm(2)/s, respectively. No statistically significant difference was found between prechemotherapy and postchemotherapy apparent diffusion coefficient values in nonresponders. Differences were statistically significant between responders and nonresponders at prechemotherapy, 2 weeks after chemotherapy, and 4 weeks after chemotherapy ( P = 0.014, P = .001, and P = .000, respectively). Receiver operating characteristic curves showed that apparent diffusion coefficient values could predict treatment response early at 2 weeks after chemotherapy with 64.5% sensitivity and 91.8% specificity. CONCLUSION: The change in apparent diffusion coefficient value may be a sensitive indicator to predict early response to chemotherapy in breast cancer liver metastases.