Endoscopic Ultrasound-Guided Fine-Needle Injection of Hydrogen Peroxide into the Pancreas: Feasibility and Tolerability Study Using a Survival Porcine Model

Abstract

Hydrogen peroxide (H₂O₂) has been reported to be an effective radiation sensitizer for various cancers. A combination therapy comprising fine-needle injection (FNI) of H₂O₂ under endoscopic ultrasound (EUS) guidance and chemoradiation might improve treatment outcomes of pancreatic cancer; however, there have been no reports thus far. The aims of this study were to evaluate the feasibility and safety of EUS-FNI of H₂O₂ into the pancreas using a porcine survival model. EUS-FNI was performed in the pancreas of six pigs, which were randomly divided into three groups based on the solution injected: group 1, 2 mL of sodium hyaluronate (control); group 2, 0.5 mL of H₂O₂; group 3, 2 mL of H₂O₂. To evaluate any adverse events, blood tests and computed tomography (CT) were performed before and after FNI, as well as days 3 and 7 subsequently. The pigs were necropsied on day 7. Histologic evaluation was performed according to the criteria for experimental acute pancreatitis. EUS-FNI was successful in all pigs. CT immediately after FNI revealed gas formation in the FNI area in groups 2 and 3. No adverse events were revealed by blood tests and CT. Histologic evaluations revealed pancreatitis scores of 5 and 5 in group 1, 7 and 7 in group 2 and 14 and 15 in group 3. EUS-FNI of H₂O₂ into the pancreas is feasible; however, it could cause pancreatitis. FNI of H₂O₂ into only the pancreatic tumor might be ideal in minimizing possible adverse events.

Keywords: Chemoradiation; Endoscopic ultrasound; Fine-needle injection; Pancreatic cancer; Radiation sensitizer.