The effects on basal anterior pituitary hormone concentrations by cranial irradiation in patients with nasopharyngeal carcinoma.

Hypopituitarism occurring in patients who received external cranial radiation therapy (RT) have been increasingly recognized. Fourteen healthy patients were collected as control Group I, and 25 patients with nasopharyngeal carcinoma (NPC) were enrolled as Group II. Another 18 NPC patients were enrolled as Group III. Blood was sampled from Group I, Group IIB (before RT), Group IIA (one week after RT) and Group IIIA (1 to 1.5 years after RT). The basal samples were taken for growth hormone (GH), adrenocorticotropic hormone (ACTH), cortisol, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyrotropin (TSH), triiodothyronine (T3) and thyroxine (T4). The results showed the T3 level was statistically low in Group IIB compared with Group I. The serum GH and FSH (male only) levels were higher and with statistical significance in Group IIA compared Group IIB. Both GH and ACTH levels decreased and PRL increased with statistical significance in Group IIIA compared with Group IIA. The ACTH decreased with statistical significance in Group IIIA compared with Group IIB. Clinical damage to the pituitary is usually manifested months to years after RT. Therefore, a careful exclusion of these glands from radiation treatment fields is recommended whenever possible.