RENAL-FUNCTION AFTER UNILATERAL NEPHRECTOMY FOR WILMS-TUMOR - THE INFLUENCE OF RADIATION-THERAPY

The effect of therapy on renal function after unilateral nephrectomy f or Wilms' tumour was studied. In the second year following unilateral nephrectomy, glomerular filtration rate (GFR) and effective renal plas ma flow (ERPF) were estimated simultaneously by measuring I-125-iothal amate clearance and I-131-hippurate clearance. Of 41 evaluable patient s, 29 received chemotherapy as sole treatment modality following nephr ectomy (group 1); 12 patients additionally received radiation therapy to a field that included the remaining kidney (group 2). Results were expressed as standard deviation scores (z-scores). In group 1, mean z- score for GFR was -0.27 (94.6% of normal) and in group 2 mean z-score was -1.51 (72.7% of normal for two kidneys) (P = 0.022, Mann-Whitney U -test). Mean z-score for ERPF was -0.09 (97.0%) in group 1 and -1.53 ( 73.8%) in group 2 (P = 0.039). It was concluded that the combination o f chemotherapy and radiation therapy, in contrast to chemotherapy alon e, negatively affects the ability of the remaining kidney to adjust it s function after the loss of its counterpart.