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Published on: October 18, 2011
Endocrine consequences of brain irradiation
1Department of Medicine, Division of Medical Science, University of Birmingham, Edgbaston, Birmingham B15 2TH, UK. a.a.toogood@bham.ac.uk
Summary
Cranial radiation for brain tumors can damage the hypothalamic-pituitary axis, leading to hypopituitarism. Long-term endocrinological follow-up is crucial for patients receiving this treatment.
Area of Science:
- Endocrinology
- Radiation Oncology
- Pediatric Oncology
Background:
- Cranial radiation therapy is a common treatment for various brain and head/neck tumors, including pituitary tumors and acute lymphoblastic leukemia.
- The hypothalamic-pituitary axis is vulnerable to radiation, potentially causing hypopituitarism.
- The severity of pituitary dysfunction depends on radiation dose and time elapsed since treatment.
Purpose of the Study:
- To review the effects of cranial radiation on the hypothalamic-pituitary axis.
- To outline the pattern of pituitary hormone deficiencies following cranial irradiation.
- To emphasize the need for long-term endocrinological monitoring.
Main Methods:
- Review of existing literature on cranial radiation effects on the pituitary gland.
- Analysis of hormone sensitivity to radiation, from most to least sensitive: GH, gonadotropins, ACTH, TSH.
- Description of dose-dependent effects on puberty and hormone axes.
Main Results:
- Growth hormone (GH) is the most sensitive anterior pituitary hormone to radiation, followed by gonadotropins, ACTH, and TSH.
- Low-dose irradiation can cause precocious puberty followed by gonadotropin deficiency; higher doses lead to gonadotropin deficiency and pubertal delay.
- ACTH and TSH axes are relatively resistant, but minor abnormalities can occur.
Conclusions:
- Cranial irradiation affecting the hypothalamic-pituitary axis poses a long-term risk of multiple hormone deficiencies.
- Patients require lifelong endocrinological surveillance to manage potential hypopituitarism.
- Early detection and management of hormone deficiencies are essential for patient outcomes.
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