Hypothalamic-pituitary dysfunction following external cranial irradiation

Abstract EN

Background : Deficiency of one or more anterior pituitary hormones may follow treatment with external radiation when the hypothalamic-pituitary axis falls in the fields of radiation.

Patients and methods : Twenty eight patients (12 children with a mean age of 6.92 ± 2.78 years and 16 adults with a mean age of 36.56±13.38 years) were included in the study.

The radiation dose received ranged from 28 to 50 Gy in children and 45 to 60 in adults.

Serum concentration of GH was measured with insulin, basal serum estimation of thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone were estimated before and after irradiation.

Results : Eight patients in the pediatric group (66%) and 2 patients in the adult group had GH deficiency.

Fifty percent of the pediatric group and 6.25% of the adult group had low serum TSH.

Three patients in the pediatric group had ACTH deficiency.

Twenty five percent of the pediatric group and 6.25% of the adult group had low serum LH / FSH.

Four patients in both groups had elevated PRL.

Testosterone level was low in three patients in the pediatric group and one patient in the adult group.

There were significant negative correlation between serum peak GH, ACTH, LH / FSH, testosterone and the dose of irradiation.

Conclusion : Patients exposed to high-dose radiotherapy ( > 35 Gy) to the hypothalamic-pituitary axis, a variety of endocrine abnormalities may occur, including deficiencies of GH, TSH, ACTH and LH/FSH as well as hypersecretion of prolactin.