PD-0003 Comparison of GD-EOB-DTPA Enhanced Mri and Contrast-Enhanced Intraoperative Ultrasound using Sonazoid in Patients Undergoing Liver Resection for Colorectal Liver Metastasis

Abstract

ABSTRACT Introduction Two imaging modalities dedicated for liver specific phase, namely Gd-EOB-DTPA enhanced MRI (EOB-MRI) and contrast-enhanced intraoperative ultrasound (CE-IOUS) using Sonazoid have been recently developed. Both are reportedly useful for diagnosis and staging in patients undergoing surgery for colorectal liver metastasis. The aim of this study is to compare diagnostic ability of these modalities. Methods A prospective clinical trial has been undertaken (UMIN-CTR ID: 000005537). Consecutive 84 patients with colorectal liver metastasis were scheduled for liver resection between January 2011 and November 2011. Of these, 66 patients underwent contrast-enhanced CT, EOB-MRI, preoperative contrast-enhanced ultrasound, fundamental intraoperative ultrasound, CE-IOUS, and liver resection of curative intent. Eighteen patients were excluded from this trial because they underwent laparoscopic liver resection (n = 7), did not undergo contrast-enhanced CT due to a history of allergy (n = 1), underwent probe laparotomy due to peritoneal metastasis (n = 1), had more than ten liver metastases (n = 9). Hepatobiliary phase was referred for diagnosis of liver metastasis in EOB-MRI. After laparotomy and exploration including fundamental IOUS, 0.5 ml of Sonazoid was injected through peripheral vein. Thorough liver screening on CE-IOUS was performed 10 to 15 minutes later under harmonic mode, where hypoechoic liver lesions were regarded as liver metastases. A nodule which was temporary diagnosed as metastasis in any imaging modality was resected. Radiofrequency ablation was not performed. All possible liver metastases were resected as long as it was identified by IOUS. Intraoperative needle biopsy was allowed alternative to resection for indeterminate nodules. Results A total of 190 nodules were temporary diagnosed as liver metastases in at least one imaging modality in the 66 patients. Of 190, 177 were diagnosed as adenocarcinoma in histological examination, 8 were adversely diagnosed as benign lesion in histological examination, and the other 5 could not be identified during operation and were finally diagnosed benign through postoperative follow-up. Fifteen were newly found during IOUS and 11 of them were finally diagnosed as adenocarcinoma. Thirteen were newly found during CE-IOUS and 11 of them were finally diagnosed as adenocarcinoma. Sensitivity and positive-predictive value were 83 and 97% for contrast-enhanced CT, 83 and 97% for EOB-MRI, 76 and 96% for preoperative contrast-enhanced ultrasound, 89 and 96% for fundamental IOUS, and 98 and 97% for CE-IOUS. Conclusion EOB-MRI and contrast-enhanced CT are complementary to each other. CE-IOUS scored high diagnostic value for diagnosis of colorectal liver metastasis.