Tissue damage after single high-dose intraoperative irradiation of the canine liver: evaluation in time by means of radionuclide imaging and light microscopy.

To establish the tolerance of liver tissue to single high-dose intraoperative irradiation, the histopathological changes in the canine liver after single high-dose intraoperative irradiation were investigated by means of radionuclide imaging and light microscopy. Intraoperative irradiation at doses of 0, 10, 20, 25 or 30 Gy was applied to a part of the liver of 25 beagles. Radionuclide imaging using (99m)Tc-sulfur colloid was performed at several times during follow-up. Elective humane killing was done 3 months and 1, 2, 3 and 5 years after irradiation. Light microscopy was used to identify histopathological alterations. There was no morbidity or mortality during a maximal follow-up of 5 years. In 40% of the animals, a region of diminished uptake was observed at the irradiation site. The regions of diminished uptake of the radiopharmaceutical agent became smaller with time. Light microscopic examination revealed severe parenchymal fibrosis, liver cell atrophy, and bile duct proliferation at the irradiated area 1 to 2 years after irradiation. At 3 and 5 years, vascular changes with endothelial proliferation and focal arteriolar hyalinosis were observed. This study demonstrates that intraoperative irradiation of a part of the liver in the canine model can be applied safely. Light microscopy confirmed that histological damage was not always accompanied by diminished uptake of the radiopharmaceutical agent at the irradiation site.

Radionuclide renography to evaluate urodynamically expected upper tract obstruction in patients with meningomyelocele.

Radionuclide renography showed an obstructed pattern in 6 patients with meningomyelocele without dilatation of the upper urinary tract or reflux when the bladder was filled to the volume that during previous urodynamic testing had resulted in an intravesical pressure of 40 cm. water but not when these patients were studied with an empty bladder. Therefore, this study indicates that treatment should be directed at avoiding long-standing intravesical pressure exceeding 40 cm. water in patients with meningomyelocele.