Correlation between response to chemotherapy with concomitant bevacizumab for hepatic metastasis of colorectal cancer and degree of enhancement using contrast-enhanced computed tomography

摘要

Purpose: The imaging factor predicting the response to bevacizumab (BV) as concomitant chemotherapy has yet to be determined. This study examined correlation between response to chemotherapy with concomitant BV for hepatic metastasis of colorectal cancer and degree of contrast enhancement (CE) using contrast-enhanced computed tomography (CT). Methods: Data were analyzed retrospectively for 35 patients treated with oxaliplatin-based chemotherapy as the first-line chemotherapy. Patient data were divided according to treatment with concomitant BV (BV group: n = 20, non-BV group: n = 15). Using an image control system, the degree of CE was evaluated by the ratio of the contrast-enhanced CT value of hepatic metastatic lesions to plain CT value, whereby patients were classified into the high-CE and low-CE group. Results: After completion of chemotherapy treatment, the degree of enhancement of hepatic metastasis in the BV group was significantly lower than that in the non-BV group (p = 0.03). In the BV group, a significant correlation between higher contrast enhancement and higher tumor shrinkage rate was observed (R 2 = 0.25, p = 0.03), whereas no such correlation was noted in the non-BV group. In the high-CE group (n = 18), the tumor shrinkage rate increased to 29.6 % in the BV group compared with -1.46 % in the non-BV group (p = 0.03), whereas in the low-CE group, no significant difference was noted between patients in the two groups. Conclusion: Pretreatment evaluation of the degree of CE correlated with the response to concomitant chemotherapy with BV.