Predicting chemotherapeutic response for colorectal liver metastases using relative tumor enhancement of gadoxetic acid disodium-enhanced magnetic resonance imaging.

Abstract

This study aimed to predict the treatment response for colorectal liver metastases (CLM) using relative tumor enhancement (RTE) of the hepatobiliary phase (HBP) for patients with no history of chemotherapy. In this retrospective study, we enrolled 26 patients [14 males, 12 females; median age: 58years (range 37-82years)] with CLM and no history of chemotherapy between December 2011 and May 2017. Gadoxetic acid-enhanced magnetic resonance imaging was performed before starting chemotherapy and RTE of HBP. The response was evaluated using RECIST ver.1.1, and progression-free survival (PFS) was estimated. Based on the RECIST ver.1.1, there were 15 responders and 11 non-responders. In the tumor, the mean pretreatment RTE values were significantly higher in the responders group than in the non-responders group (37.2%±10.9% vs. 17.9%±10.5%, respectively; P=0.0006). When the threshold values of parameters for detecting responders comprised the RTE value of 24.2% (area under the curve value, 0.90), the sensitivity and specificity were 93.3% and 72.7%, respectively. The median follow-up period for 26 patients was 602days (range 160-1971days). Although no significant differences were observed in PFS between the groups, the high RTE group tended to take longer to progress than the low RTE group (PFS of the high RTE group did not reach the median). This study suggests that the RTE value of CLM could be a potential biomarker to predict early treatment response.