Radioprotection of the kidney with degradable microspheres. A pilot study in the dog with repeated irradiation

The left kidney of 9 dogs was irradiated daily for three days with 300 kVp X-rays. Radioprotection was attempted in 5 of the kidneys by administration of degradable microspheres in the renal artery, immediately before irradiation. Protected kidneys received 3 X 8 or 3 X 12 Gy in midplane dose, unprotected kidneys 3 X 5.2 or 3 X 8 Gy. A protective effect due to induced hypoxia could be demonstrated in creatinine clearance, which was significantly higher in protected than in unprotected kidneys at 7 - 13 weeks after irradiation.