Therapy for regionally unresectable pancreatic cancer

Evaluation of the feasibility of intrapancreatic delivery of drug-loaded microparticles via EUS-guided fine needle injection using a swine model

Background and study aims  Patients with pancreatic cancer often have locally advanced or metastatic disease and are not candidates for curative surgery. Polymer-based microparticles (MPs) represent a drug delivery system that offers sustained release of a chemotherapeutic drug after intralesional injection for local tumor management. The aim of this study was to determine the feasibility of endoscopic ultrasound-guided fine-needle injection (EUS-FNI) of drug-loaded MPs tagged with a fluorophore and fiducial markers for locating the injection site. Secondary aims were to determine the tissue-specific effects of MPs. Methods  Five pigs underwent EUS with selection of an injection site within the pancreas that was marked by placing fiducial markers prior to the MPs injection. EUS-FNI of either blank microparticles (BMPs), containing no drug, or gemcitabine-loaded microparticles (GMPs) was performed. A saline flush containing Spot Endoscopic Marker was used to expel any residual MPs in the needle shaft and tattoo the injection site. Results  A green fluorescent protein flashlight was used to successfully identify the site of MP injection sites in the dissected pancreas. Frozen sections of pig pancreas demonstrated a defined deposit, confirming the delivery of the MPs. Finally, fluorescence microscopy showed activation of caspase-mediated cell death in pancreases of animals that received injections of GMPs. Conclusions  This pilot study demonstrated that fiducial marker placement and pancreatic EUS-FNI of MPs was successful in all pigs with no animals demonstrating pancreatitis. Further studies are needed to determine the role for intralesional injection of drug-loaded MPs in borderline resectable or unresectable pancreatic cancer.

Cancer of the Pancreas-Actual 5, 10, and 20+Year Survival: The Lucky and Fortunate Few

Cancer of the pancreas (CaP) is a dismal, uncommon, systemic malignancy. This article updates an earlier experience of actual long-term survival of CaP in patients treated between 1991 to 2000, and reviews the literature. Survival is expressed as actual, not projected, survival.

Concentration-dependent ablation of pancreatic tissue by EUS-guided ethanol injection

BACKGROUND

Ethanol is a commonly available agent and has been used to successfully and safely ablate cystic lesions of various organs.

OBJECTIVE

The aim of this study was to determine the short-term effects of an EUS-guided injection of ethanol into the pancreas of pigs by using 2 mL ethanol, in increasing concentration of 0% to 100%.

DESIGN

Six pigs were sedated by general anesthesia, and ethanol was injected, under EUS-guidance, with a 22-gauge needle into the pancreatic tail.

MAIN OUTCOME MEASUREMENTS

End points of this study were gross and microscopic evidence of pancreatitis and clinical tolerance. During the 7-day observational period, the animals were monitored by serum levels of amylase and lipase and by a CT on day 4.

RESULTS

At euthanasia, there was no pancreatic lesion in the animals that received normal saline solution or 20% ethanol. The injection of 40% to 100% ethanol led to a visible necrotic area in the pancreatic tail. By histology, the average maximal diameter of the lesions was 20.8 +/- 4.3 mm. The cross-sectional area of necrosis was proportional to the concentration of ethanol (r = 0.961). CT demonstrated a localized site of nonenhancing pancreatic tissue, with an average diameter of 19.4 +/- 10.5 mm; 40% to 100% ethanol. Clinically, the animals appeared to tolerate the procedure without sequelae. Serum levels of amylase and lipase were normal.

CONCLUSIONS

The EUS-guided injection of ethanol into the pig pancreas resulted in a localized concentration-dependent tissue necrosis without complications.