THE EFFECT OF VARYING DOSES OF CEREBRAL IRRADIATION ON GROWTH HORMONE PRODUCTION IN CHILDHOOD

Abstract

The radiation dose, delivered to the hypothalamic‐pituitary region, has been calculated in thirty‐nine children irradiated for brain tumours and in seventeen children who had received prophylactic cranial irradiation for acute leukaemia. All subjects had an insulin tolerance test at least 2 years after their radiotherapy. There is a significant inverse correlation between radiation dose and peak GH response. Thirty‐seven of the fifty‐six patients showed an impaired GH response and thirty‐six of these received more than 2900 rads. Only five patients who received such a dose showed normal GH responses and four of these were aged over 13 years when treated. In conclusion, cerebral irradiation is a potent cause of GH deficiency in children.