The effects of growth hormone therapy in children with radiation-induced growth hormone deficiency.

The effects of growth hormone (GH) therapy were studied in 6 children, previously treated for brain tumours which did not directly involve the hypothalamic-pituitary axis, and who had received cranial irradiation between 2.1 and 10 years earlier. All 6 were short with a standing height standard deviation score (SDS) from -1.7 to -3.3. Impaired growth hormone responses to an insulin tolerance test (ITT) were observed in all 6 and to a Bovril stimulation test in 5 children. The remainder of pituitary function was essentially normal. All 6 were prepubertal and 5 had a retarded bone age. During the pre-treatment year the 6 children's growth rates varied fom 2.0 to 5.1 cm. Subsequently all received human GH in a dose of 5 units 3 times weekly for 1 year. The growth rate in each was at least 2 cm greater during the treatment year than the pre-treatment year. Growth during the treatment year ranged from 6.0 to 10.1 cm. In 5 of the 6 the improvement in growth rate could be totally ascribed to the GH therapy. In the sixth there was significant pubertal maturation during the treatment year and only in this subject did the bone age advance at a significantly greater rate than the chronological age.