RESUMEN
The effect of prophylactic postoperative radiotherapy on peripheral lymphocyte count was determined for 20 cases of urogenital malignant tumors (bladder cancer-13 cases, prostatic cancer-4 cases, renal cancer-3 cases). The results were obtained as follows, l) Radiotherapy decreased the white blood cell count by a mean percentage of 16.7% (14.0% for bladder cancer, 16.4% for prostatic cancer. 36.8% for renal cancer, respectively) during the period of first month, but did not alter the granulocyte count. 2) Radiotherapy brought about high degree of decrease of peripheral lymphocyte count by a mean percentage of 47.9% (47. 3% for bladder cancer. 50.0% for prostatic cancer. 32.3% for renal cancer, respectively). 3) The recovery of the radiation-induced lymphocyte deficiency to pre-irradiation level was observed in 1-2 years after completion of radiation therapy (2 years for bladder cancer. 1 1/2 years for prostatic cancer. 1 year for renal cancer. respectively).