Related Experiment Videos
Cranial irradiation and central hypothyroidism.
1Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA. susan.rose@chmcc.org
Trends in Endocrinology and Metabolism: TEM
|April 18, 2001
Summary
Cranial irradiation can disrupt thyroid hormone regulation, causing central or mixed hypothyroidism. Early monitoring and thyroid hormone replacement are vital for cancer survivors' health.
Area of Science:
- Endocrinology
- Oncology
- Neuroendocrinology
Background:
- Cranial irradiation is a known cause of thyrotropin-releasing hormone (TRH) secretory abnormalities.
- TRH deficiency disrupts the normal circadian rhythm and glycosylation of thyroid-stimulating hormone (TSH) subunits.
Purpose of the Study:
- To investigate the incidence and clinical implications of TRH deficiency and subsequent hypothyroidism after cranial irradiation.
- To highlight the importance of monitoring thyroid function in cancer survivors.
Main Methods:
- The study focuses on analyzing the effects of cranial irradiation on TRH secretion and TSH dynamics.
- Clinical monitoring of free thyroxine (FT4) and TSH levels, including TSH surge and TRH tests, are discussed.
Main Results:
- Cranial irradiation leads to TRH deficiency, resulting in abnormal TSH secretion patterns (central or mixed hypothyroidism).
- The cumulative incidence of these conditions is significant within ten years post-irradiation.
- Primary hypothyroidism, while common, is distinct from radiation-induced central/mixed forms.
Conclusions:
- Early detection of thyroid dysfunction through monitoring FT4 and TSH is crucial.
- Thyroid hormone replacement therapy, aiming for FT4 in the upper normal range, is essential for optimal health and growth in survivors.