Feasibility of ablating normal renal parenchyma by interstitial photon radiation energy: study in a canine model.

BACKGROUND AND PURPOSE: A miniature photon radiosurgery system (PRS) has been described as an alternative to surgical resection and external-beam radiation for tumors and may now offer an alternative for ablation of renal lesions. We evaluated the feasibility of ablation by PRS in a normal parenchyma canine model. MATERIALS AND METHODS: Twelve mongrel dogs were used in this survival study. In the left and right kidneys of each animal, a peripheral lesion and central-hilar lesion, respectively, were induced with PRS. The probes were placed in the renal parenchyma, and local radiation of 15 Gy at a radius of 1.3 cm was delivered over 10 minutes. Serum electrolytes were measured serially. Computed tomography scans were obtained, and the animals were sacrificed for pathologic correlation. In a separate study, the liver received three additional treatments of 10 to 20 minutes of radiation. RESULTS: Eleven dogs survived this 6-month study and were sacrificed as scheduled. One animal expired after 2 weeks from radiation-induced fulminant hepatic failure with normal renal function. No other complications were observed. The average lesion size was 2.5 cm in diameter. Histologic analysis confirmed coagulative necrosis with sharp demarcation from the surrounding parenchyma. CONCLUSION: Preliminary studies demonstrate the feasibility of PRS ablation of the renal parenchyma. Further tumor model testing will be important to determine the ultimate efficacy of local photon radiation energy.

The study of heptenophos and triazophos residues in vegetables treated with the organophosphorus insecticides Hostaquick and Hostathion.

The residues of heptenophos and triazophos (active components of Hostaquick and Hostathion) were determined in several vegetable crops during the growing period. Heptenophos residues decreased below the limit of detection (0.001 mg/kg) in most of the crops one week after the treatment. However, the decline of triazophos in vegetables below the limit of detection (0.002 mg/kg) depended on the method of crop treatment.

Residues of cycloate and influence of herbicides on some of nutritional factors in spinach.

The influence of cycloate (active component of Ro-Neet 6E) on the biological value and residues in spinach was studied. During the growing season of spinach, cycloate residues decreased rapidly until by harvest time levels 0.0005--0.0008 mg/kg. had been reached. None of the studied herbicides had negative influence on the chemical composition of spinach.