CLINICAL STUDY Transarterial Chemoembolization with Irinotecan Beads in the Treatment of Colorectal Liver Metastases: Systematic Review Arthur J. Richardson, MBBS, FRACS, Jerome M. Laurence, MBChB, MRCS, PhD, FRACS, and Vincent W.T. Lam, MBBS, MS, FRACS ABSTRACT Purpose: For patients with unresectable colorectal liver metastasis (CRLM), transarterial embolization with the use of drug- eluting beads with irinotecan (DEBIRI) represents a novel alternative to systemic chemotherapy or local treatments alone. The present systematic review evaluates available data on the efficacy and safety of DEBIRI embolization. Materials and Methods: A comprehensive search of medical literature identified studies describing the use of DEBIRI in the treatment of CRLM. Data describing adverse events, pharmacokinetics, tumor response, and overall survival were collected. Results: Five observational studies and one randomized controlled trial (RCT) were reviewed. A total of 235 patients were included in the descriptive analysis of observational studies. Postembolization syndrome was the most common adverse event. Peak plasma levels of irinotecan were observed at 1–2 hours after administration. Wide variations in tumor response were observed. The median survival time ranged from 15.2 months to 25 months. In the RCT, treatment with DEBIRI was superior to systemic chemotherapy with 5-fluorouracil/leucovorin/irinotecan in terms of quality of life and progression-free survival. Conclusions: For patients with unresectable CRLM, particularly after failure to respond to first-line regimens, DEBIRI represents a novel alternative to systemic chemotherapy alone, transarterial embolization with other agents, or other local treatments (eg, microwave or radiofrequency ablation). In these reports, DEBIRI was safe and effective in the in the treatment of unresectable CRLM. Further RCTs comparing DEBIRI with alternative management strategies are required to define the optimal role for this treatment. ABBREVIATIONS CR = complete response, CRLM = colorectal liver metastasis, DEB = drug-eluting bead, DEBIRI = drug-eluting beads with irinotecan, 5-FU = 5-fluorouracil, FOLFIRI = 5-fluorouracil/leucovorin/irinotecan, FOLFOX = 5-fluorouracil/leucovorin/ oxaliplatin, OS = overall survival, PFS = progression-free survival, PR = partial response, QoL = quality of life, RCT = randomized controlled trial, SD = standard deviation Colorectal cancer is the third most common cancer worldwide (1). Synchronous colorectal liver metastases (CRLMs) will be present at the time of diagnosis in 15%–20% of patients, and another 50% of patients will develop metachronous CRLM (2). Nevertheless, although the liver is the sole site of metastatic disease in as many as 40% of patients, CRLM is resectable in fewer than 20% of cases (3). Until the past decade, 5-fluorouracil (5-FU) and leucovorin were the stan- dard chemotherapy for unresectable CRLMs, and this doubled median survival to approximately 12 months (4). The use of irinotecan and oxaliplatin have improved median survival times to approximately 20 months (5), with a small additional benefit from the addition of biologic agents such as bevacizumab and cetuximab (6,7). Nevertheless, many patients are unable to undergo surgery and have to be treated with other techniques. Transarterial chemoembolization, combines injection of drug and embolic material and has mostly been used in hypervascular tumors such as hepatocellular carci- noma and neuroendocrine liver metastases (8,9). The use & SIR, 2013 J Vasc Interv Radiol 2013; 24:1209–1217 http://dx.doi.org/10.1016/j.jvir.2013.05.055 None of the authors have identified a conflict of interest. From the Department of Surgery, Westmead Hospital, Wentworthville; and Discipline of Surgery, University of Sydney, Sydney, Australia. Received February 16, 2013; final revision received May 15, 2013; accepted May 22, 2013. Address correspondence to A.J.R., Department of Surgery, West- mead Hospital, 106b/151 Hawkesbury Rd., Wentworthville, NSW 2145, Australia; E-mail: aj.richardson@bigpond.com