EVALUATION OF GROWTH-HORMONE RELEASE AND HUMAN GROWTH-HORMONE TREATMENT IN CHILDREN WITH CRANIAL IRRADIATION ASSOCIATED SHORT STATURE

Nine children who had received cranial irradiation for various malignancies and subsequently experienced decreased growth velocity were studied. Their responses to standard growth hormone [GH] stimulation and release tests were compared with that in 7 children with classic GH deficiency and in 24 short normal control subjects. With arginine and L-dopa stimulation, 6 of 9 patients who received radiation had a normal GH response (> 7 ng/ml); by design none of the GH deficient and all of the normal children had a positive response. Only 2 of 9 patients had a normal response to insulin hypoglycemia, with no significant differences in the mean maximal response of the radiation and the GH-deficient groups. Pulsatile secretion was not significantly different in the radiation and GH-deficient groups but was different in the radiation and normal groups. All subjects in the GH-deficient and radiation groups were given human GH [hGH] for 1 yr. Growth velocity increased in all, with no significant difference in the response of the 2 groups when comparing the z scores for growth velocity of each subject''s bone age. A 6-mo. trial of hGH in children who have had cranial radiation and are in prolonged remission with a decreased growth velocity is recommended as there is no completely reliable combination of GH stimulation or release tests to determine their response.