2.50
Hdl Handle:
http://hdl.handle.net/10541/69753
Title:
Hypopituitarism following Radiotherapy Revisited.
Authors:
Darzy, Ken H; Shalet, Stephen M
Abstract:
Neuroendocrine disturbances in anterior pituitary hormone secretion are common following radiation damage to the hypothalamic-pituitary (H-P) axis, the severity and frequency of which correlate with the total radiation dose delivered to the H-P axis and the length of follow-up. The somatotropic axis is the most vulnerable to radiation damage and GH deficiency remains the most frequently seen endocrinopathy. Compensatory hyperstimulation of a partially damaged somatotropic axis may restore normality of spontaneous GH secretion in the context of reduced but normal stimulated responses in adults. At its extreme, endogenous hyperstimulation may limit further stimulation by insulin-induced hypoglycaemia resulting in subnormal GH responses despite the normality of spontaneous GH secretion. In children, failure of the hyper-stimulated partially damaged H-P axis to meet the increased demands for GH during growth and puberty may explain what has previously been described as radiation-induced GH neurosecretory dysfunction and, unlike in adults, the insulin tolerance test remains the gold standard for assessing H-P functional reserve. With low radiation doses (<30 Gy) GH deficiency usually occurs in isolation in about 30% of patients, while with radiation doses of 30-50 Gy, the incidence of GH deficiency can reach 50-100% and long-term gonadotropin, TSH and ACTH deficiencies occur in 20-30, 3-9 and 3-6% of patients, respectively. With higher dose cranial irradiation (>60 Gy) or following conventional irradiation for pituitary tumours (30-50 Gy), multiple hormonal deficiencies occur in 30-60% after 10 years of follow-up. Precocious puberty can occur after radiation doses of <30 Gy in girls only, and in both sexes equally with a radiation dose of 30-50 Gy. Hyperprolactinaemia, due to hypothalamic damage is mostly seen in young women after high dose cranial irradiation and is usually subclinical. H-P dysfunction is progressive and irreversible and can have an adverse impact on growth, body image, sexual function and quality of life. Regular testing is advised to ensure timely diagnosis and early hormone replacement therapy.
Affiliation:
Department of Endocrinology, Christie Hospital NHS Trust, Manchester, UK.
Citation:
Hypopituitarism following Radiotherapy Revisited. 2009, 15:1-24 Endocr Dev
Journal:
Endocrine Development
Issue Date:
2009
URI:
http://hdl.handle.net/10541/69753
DOI:
10.1159/000207607
PubMed ID:
19293601
Type:
Article
Language:
en
ISSN:
1421-7082
Appears in Collections:
All Christie Publications ; Endocrinology

Full metadata record

DC FieldValue Language
dc.contributor.authorDarzy, Ken H-
dc.contributor.authorShalet, Stephen M-
dc.date.accessioned2009-06-05T09:14:27Z-
dc.date.available2009-06-05T09:14:27Z-
dc.date.issued2009-
dc.identifier.citationHypopituitarism following Radiotherapy Revisited. 2009, 15:1-24 Endocr Deven
dc.identifier.issn1421-7082-
dc.identifier.pmid19293601-
dc.identifier.doi10.1159/000207607-
dc.identifier.urihttp://hdl.handle.net/10541/69753-
dc.description.abstractNeuroendocrine disturbances in anterior pituitary hormone secretion are common following radiation damage to the hypothalamic-pituitary (H-P) axis, the severity and frequency of which correlate with the total radiation dose delivered to the H-P axis and the length of follow-up. The somatotropic axis is the most vulnerable to radiation damage and GH deficiency remains the most frequently seen endocrinopathy. Compensatory hyperstimulation of a partially damaged somatotropic axis may restore normality of spontaneous GH secretion in the context of reduced but normal stimulated responses in adults. At its extreme, endogenous hyperstimulation may limit further stimulation by insulin-induced hypoglycaemia resulting in subnormal GH responses despite the normality of spontaneous GH secretion. In children, failure of the hyper-stimulated partially damaged H-P axis to meet the increased demands for GH during growth and puberty may explain what has previously been described as radiation-induced GH neurosecretory dysfunction and, unlike in adults, the insulin tolerance test remains the gold standard for assessing H-P functional reserve. With low radiation doses (<30 Gy) GH deficiency usually occurs in isolation in about 30% of patients, while with radiation doses of 30-50 Gy, the incidence of GH deficiency can reach 50-100% and long-term gonadotropin, TSH and ACTH deficiencies occur in 20-30, 3-9 and 3-6% of patients, respectively. With higher dose cranial irradiation (>60 Gy) or following conventional irradiation for pituitary tumours (30-50 Gy), multiple hormonal deficiencies occur in 30-60% after 10 years of follow-up. Precocious puberty can occur after radiation doses of <30 Gy in girls only, and in both sexes equally with a radiation dose of 30-50 Gy. Hyperprolactinaemia, due to hypothalamic damage is mostly seen in young women after high dose cranial irradiation and is usually subclinical. H-P dysfunction is progressive and irreversible and can have an adverse impact on growth, body image, sexual function and quality of life. Regular testing is advised to ensure timely diagnosis and early hormone replacement therapy.en
dc.language.isoenen
dc.subjectPaediatric Canceren
dc.subjectBrain Canceren
dc.subject.meshAdrenocorticotropic Hormone-
dc.subject.meshBrain Neoplasms-
dc.subject.meshChild-
dc.subject.meshCranial Irradiation-
dc.subject.meshGonadotropins-
dc.subject.meshHuman Growth Hormone-
dc.subject.meshHumans-
dc.subject.meshHypopituitarism-
dc.subject.meshPituitary Diseases-
dc.subject.meshProlactin-
dc.subject.meshRadiation Injuries-
dc.subject.meshRadiobiology-
dc.subject.meshThyrotropin-
dc.titleHypopituitarism following Radiotherapy Revisited.en
dc.typeArticleen
dc.contributor.departmentDepartment of Endocrinology, Christie Hospital NHS Trust, Manchester, UK.en
dc.identifier.journalEndocrine Developmenten
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