[Suppression of testicular testosterone production by irradiation of the testis in prostatic cancer].

Irradiation of the tests of 11 patients with carcinoma of the prostate in the age from 68 to 78 years with 20 Gy (5 X 2 Gy per week) decreased the plasma testosterone levels to an average of 70,3% of the initial values. After operative orchidectomy, however, a decrease of the plasma testosterone level to only 5% the values before operation was observed. Therefore, the operative orchidectomy cannot be replaced by the irradiation of the testes. Higher irradiation doses may cause skin injuries and there is the possibility of being a real carcinogen noxe for the irradiation region too.