Feasibility of EUS-guided injection of irinotecan-loaded microspheres into the swine pancreas

Background: LC beads (Biocompatibles International plc) are designed for the time-released delivery of the chemotherapeutic agent irinotecan into focal, hypervascularized, hepatic tumors.

Objective: To determine the feasibility of EUS-guided injection of LC beads (with/without irinotecan) into the swine pancreas.

Design: Survival animal study.

Setting: Academic center.

Subjects: This study involved 12 Yorkshire swine.

Intervention: LC beads without irinotecan and loaded with up to 300 mg of irinotecan were injected under EUS guidance with a 19-gauge needle into the tail of the pancreas. CT scanning and necropsy with histology were performed at day 7.

Main outcome measurements: Feasibility of the injections, gross and microscopic evidence of pancreatic inflammation, and clinical tolerance by the animals.

Results: After injection of LC beads with/without irinotecan, in 10 of 12 animals an intrapancreatic, hyperechoic focus with an average diameter of 2.2 cm was visible by EUS, and a hypodense area in the tail of the pancreas was visible by contrast CT. In 2 animals (1 with irinotecan and 1 without) no beads were seen on CT. In 10 of 12 animals, a depot of beads was located in the tail of the pancreas on gross inspection and histology. Drug depot with only localized pancreatic tissue reactions was seen on histopathologic review.

Limitations: Animal study.

Conclusion: The EUS-guided injection of LC beads (with/without irinotecan) into the pancreas of the pig is feasible and safe. This technique is a potential minimally invasive local treatment option for locally advanced pancreatic cancer.