Segmental and lobar administration of drug-eluting beads delivering irinotecan leads to tumour destruction: a case-control series

Abstract

Background: Irinotecan-loaded drug-eluting beads represent a novel drug delivery method that allows for the locoregional delivery of irinotecan to colorectal liver metastases (CRLM). The method has shown impressive response rates. However, the pathological response to this treatment has not previously been demonstrated.

Methods: Patients with easily resectable CRLM were treated with drug-eluting beads delivering irinotecan (DEBIRI) 4 weeks prior to resection. Pathological tumour response was graded using a validated system. The intraoperative detection of previously unidentified disease allowed for the assessment of pathological responses directly attributable to bead treatment.

Results: In Patient 1, segmental embolization of the target lesion in segment VIII resulted in 100% necrosis (0% viability). An untreated lesion in segment IV was found to be 30% viable. In Patient 2, subsegmental embolization of the target lesion in segment VI resulted in 60% necrosis and 40% fibrosis (0% viability). An untreated lesion in segment VI remained 60% viable. In Patient 3, lobar embolization of the target lesion in segment II resulted in 0% viability. Two further lesions within the treated hemiliver, both with 0% viability, and one lesion in the untreated hemiliver with 45% viability were discovered at laparotomy.

Conclusions: This series demonstrates the effectiveness of DEBIRI in the treatment of CRLM. High rates of tumour destruction are possible, even with the proximal lobar administration of DEBIRI. Lobar administration appears to be an appropriate method of delivery for integration into future therapeutic regimens.

Trial registration: ClinicalTrials.gov NCT00844233.

© 2012 International Hepato-Pancreato-Biliary Association.

Figures

Figure 1

CONSORT (consolidated standards of reporting trials) diagram of PARAGON II study. DEBIRI-TACE, drug-eluting beads delivering irinotecan transarterial chemoembolization

Figure 2

Preoperative imaging in Patient 1 showing a small 25-mm colorectal liver metastasis in segment VIII on (a) computed tomography (CT), (b) contrast-enhanced magnetic resonance imaging and (c) positron-emission tomography-CT. No other disease was identified on preoperative imaging

Figure 3

Histopathology in Patient 2 showing (a) targeted and (b) non-targeted colorectal liver metastasis. The treated lesion shows an absence of viable tumour, with complete replacement with necrotic tissue. In (a), the irinotecan beads are clearly visible within the vasculature. By contrast, the untreated lesion (b) shows islands of viable cells with minimal necrosis and fibrosis. (Haematoxylin and eosin stain; original magnification ×20)