Hypothalamic-Pituitary Dysfunction after Irradiation of Nonpituitary Brain Tumors in Adults

Abstract

Adult patients treated with cranial irradiation for primary nonpituitary brain tumors are at high risk of hypopituitarism, which is time and dose dependent. Long-term surveillance and periodic evaluation are needed. We recommend that adult late effect clinics, similar to those for children, should be established.

Endocrine Complications Following Radiotherapy and Chemotherapy for Nasopharyngeal Carcinoma

“…It has been described in both sexes and all age groups but is most frequently encountered in the adult female with radiation doses in excess of 40 Gy. In these patients, a mild to modest elevation in prolactin level is noticed in 20-50% (Agha et al, 2005;Constine et al, 1993;Lam et al, 1991;Littley et al, 1989a;Samaan et al, 1987) compared with less than 5% in children (Rappaportet al, 1982) and after low radiation doses (Littley et al, 1991). A much higher incidence is seen following intensive irradiation; Chen et al (Chen et al, 1989) reported hyperpractinaemia in 21% and 36% in the first 4 years and after 15 years of radiotherapy in NCP, respectively.…”

“…Although abnormalities in LH/FSH secretion can be demonstrated on dynamic testing, sometimes as early as one month following high dose irradiation (Chen et al, 1989), clinically-significant gonadotrophin deficiency is usually a late complication with a cumulative incidence in excess of 20% after long term follow up whether radiation was administered in childhood or adult life (Agha et al, 2005;Constine et al, 1993;Lam et al, 1991;Rappaport et al, 1982;Samaan et al, 1987). For example, Lam et al (Lam et al, 1991) reported a cumulative incidence of 30.7% 5 years after radiation treatment of NPC, while Samaan et al (Samaan et al, 1987) reported LH and FSH deficiency in 20% and 35% of NCP patients 1-4 years and more than 15 years after radiotherapy, respectively.…”

“…With radiation doses of less than 50 Gy, the frequency of TSH deficiency remains as low as 3-6%, such as that found in survivors of non-pituitary brain tumours (Livesey et al, 1990;Oberfield et al, 1992). Patients irradiated during adulthood for non-pituitary brain tumours were reported to have 9% rate of secondary hypothyroidism (Agha et al, 2005). A higher incidence of overt secondary hypothyroidism is noted in patients with pituitary tumours (Littley et al, 1989a), but more frequently following intensive irradiation schedules utilizing doses in excess of 50 Gy, typically used for head and neck tumours including NPC (Chen et al, 1989;Constine et al, 1993;Lam et al, 1991;Pai et al, 2001;Samaan et al, 1987).…”

“…For example, isolated GH deficiency is frequently seen in children who received radiation doses of less than 24 Gy (Ogilvy-Stuart et al, 1992) but none in the adults (Littley et al, 1991). In a study of 56 patients irradiated for non-pituitary brain tumours in adulthood, Agha et al (Agha et al, 2005) reported variable degrees of hypopituitarism in 41% of patients. In this study (Agha et al, 2005), GH deficiency (32%) was less frequent that that reported in irradiated children (Clayton & Shalet, 1991;Livesey et al, 1990;Samaan et al, 1987), but ACTH (21%), TSH (9%) and gonadotropin (27%) deficiencies were relatively more common than or similar to that reported in cancer survivors irradiated during childhood (Constine et al, 1993;Livesey et al, 1990;Samaan et al, 1987).…”

Radiation therapy and CyberKnife radiosurgery in the management of craniopharyngiomas

“…11,34,37 Delayed pituitary failure after regional radiation therapy has also been well described and may occur in 30-70% of patients who receive conventional radiotherapy. 2,9,33 Other complications include secondary malignancies 3,42,49 and temporal lobe necrosis.…”