Hypothyroidism after radiation exposure: brief narrative review

Autor: Christoph Reiners, Valentina Drozd, Shunichi Yamashita
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Thyroid nodules
Adult
Pediatrics
medicine.medical_specialty
endocrine system
Autoimmune thyroiditis
endocrine system diseases
medicine.medical_treatment
030209 endocrinology & metabolism
Ionizing radiation
Neurology and Preclinical Neurological Studies - Review Article
Other radiation exposure (atomic bombing/nuclear accidents)
Iodine Radioisotopes
03 medical and health sciences
0302 clinical medicine
Hypothyroidism
medicine
Humans
External beam radiotherapy
ddc:610
Thyroid Neoplasms
Thyroid cancer
Biological Psychiatry
Thyroid
Diagnostic medical radiation exposure
business.industry
Cancer
Dose-Response Relationship
Radiation
medicine.disease
Radiation therapy
Psychiatry and Mental health
medicine.anatomical_structure
Therapeutic medical radiation exposure (EBRT/ RAI)
Neurology
030220 oncology & carcinogenesis
Neurology (clinical)
business
Zdroj: Journal of Neural Transmission
ISSN: 1435-1463
0300-9564
Popis: The thyroid gland is among the organs at the greatest risk of cancer from ionizing radiation. Epidemiological evidence from survivors of radiation therapy, atomic bombing, and the Chernobyl reactor accident, clearly shows that radiation exposure in childhood can cause thyroid cancer and benign thyroid nodules. Radiation exposure also may induce hypothyroidism and autoimmune reactions against the thyroid, but these effects are less well-documented. The literature includes only a few, methodologically weak animal studies regarding genetic/molecular mechanisms underlying hypothyroidism and thyroid autoimmunity after radiation exposure. Rather, evidence about radiation-induced hypothyroidism and thyroid autoimmunity derives mainly from follow-up studies in patients treated with external beam radiotherapy (EBRT) or iodine-131, and from epidemiological studies in the atomic bombing or nuclear accident survivors. Historically, hypothyroidism after external irradiation of the thyroid in adulthood was considered not to develop below a 10–20 Gy dose threshold. Newer data suggest a 10 Gy threshold after EBRT. By contrast, data from patients after iodine-131 “internal radiation therapy” of Graves´ disease indicate that hypothyroidism rarely occurs below thyroid doses of 50 Gy. Studies in children affected by the Chernobyl accident indicate that the dose threshold for hypothyroidism may be considerably lower, 3–5 Gy, aligning with observations in A-bomb survivors exposed as children. The reasons for these dose differences in radiosensitivity are not fully understood. Other important questions about the development of hypothyroidism after radiation exposure e.g., in utero, about the interaction between autoimmunity and hypofunction, and about the different effects of internal and external irradiation still must be answered.
Databáze: OpenAIRE
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