Proceedings Article | 1 March 1995
Peter Mlkvy, Helmut Messmann, J. Stewart, M. Pauer, Charles Millson, Alexander MacRobert, Stephen Bown
KEYWORDS: Pancreas, Stomach, Photodynamic therapy, Tissues, Luminescence, CCD cameras, Gallbladder, Blood vessels, Animal model studies, Aluminum
Experimental study has been carried out using metatetrahydroxyphenylchlorin (m-THPC) in female Syrian golden hamsters. For quantitative fluorescence study, using a CCD camera, the dose of 1.0 mg/kg bodyweight of mTHPC was given intracaval and animals were sacrificed 1 and 4 hours and 1, 2, 3, 4, 5, 6 days afterwards and specimens from the pancreas, stomach, duodenum, gallbladder, aorta and vena cava were examined. A sensitizing dose of 0.3 mg/kg and 0.1 mg/kg respectively was given for PDT, which followed after 2 and 4 days and animals were sacrificed after 1, 2, 3, 4 and 7 days. The treated areas included the pancreas, antral part of the stomach, duodenum and wedge of lesser omentum. In the treated pancreas necrosis up to 3 - 4 mm, marked ulceration in treated duodenum up to 3 - 4.5 mm and in the stomach up to 2 - 2.5 mm in diameter were observed. No macroscopic and histological signs of necrosis were seen in bile duct and major blood vessels. Sealed duodenal perforation occurred in all treated animals with 0.3 mg/kg sensitizing dose and was not observed in 0.1 mg/kg dose with protected duodenum during PDT. Using breaks during PDT (3 X 1; 3 X 3 minutes, respectively) approximately 30% increase of pancreatic necrosis has been observed. In this model, only the duodenum is at risk of irreversible damage. The risk to normal organs in this region is similar to that of photofrin and sulphonated aluminum phtalocyanine. mTHPC is a promising photosensitizer for tumors in the region of the pancreas, although care is required in the region of the duodenum.
