Abstract
The hypothalamic-pituitary function in eighteen children aged 1 to 13 years old with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL), who had received cranial irradiation (XRT) as central nervous system prophylaxis, was evaluated. Pharmacologic stimulation tests with insulin, TRH, and LHRH were performed to investigate secretory function of the anterior pituitary gland, before and after XRT, and at completion of 3 years maintenance chemotherapy. GH responses to insulin-induced hypoglycemic stimuli were subnormal in 3 of 11 patients before XRT, and 4 of 18 after XRT. Pituitary GH secretion after pharmacologic stimulus was little affected by XRT. TSH responses to TRH were decreased in 6 of 11 patients before XRT, 14 of 18 after, and 2 of 7 at completion of chemotherapy. PRL (prolactin) responses to TRH were excessive in 4 of 7 (before), 13 of 18 (after), and 2 of 7 (completion). Impaired secretions of TSH and PRL were found in the majority of patients before irradiation. Therefore endocrinological abnormalities in TSH and PRL secretion after XRT were considered to be caused not only by XRT but also other factors-i.e., TSH suppression by corticosteroid, stress-induced hyperprolactinemia. Gonadotropin secretions were normal after XRT in all patients excent two.
