Unilateral radiation nephropathy--the long-term significance

Eighteen patients with gastrointestinal and retroperitoneal non-Hodgkin's lymphoma received abdominal radiotherapy as their primary treatment. Each patient received a total tumor dose of 2200 to 4500 cGy in 5 to 9 weeks to the whole or half of one kidney. Nine patients developed unilateral radiation nephropathy demonstrable on post-treatment evaluation with 99m Tc glucoheptonate blood flow, delayed static scan, and an I-131 radio-hippurate renal perfusion study. The tests were periodically repeated over periods ranging from 5 to 8 years. Six patients with nephropathy and 4 patients without nephropathy were followed 5 years or longer. The minimum nephro-pathogenic irradiation dose was 2200 cGy delivered in 59 days. The incidence of nephropathy is higher with increase in the total dose. Short term recovery in function was observed in 3 patients and long-term complete recovery was observed in one patient. Atrophic renal change was irreversible and progressive in 3 patients over a 6 to 7 year follow-up period. In this group of patients, an abnormal creatinine clearance and serum beta-2 microglobulin level was indicative of vascular damage. Elevated arterial blood pressure was seen in 5 patients. All were controlled medically, without nephrectomy. There was no other clinically significant problem resulting from the unilateral nephropathy in this group of patients.