Hypothyroidism After Radiotherapy for Nasopharyngeal Cancer Patients

Journal Article · Mon Mar 15 04:00:00 EDT 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.03.011· OSTI ID:21372171

Wu, Y -H ^[1]; Wang, H-M ^[2]; Chen, Hellen Hi-Wen ^[1]; Lin, C -Y; Chen, Eric Yen-Chao; Fan, K -H ^[3]; Huang, S -F; Chen, I-How; Liao, C -T ^[3]; Cheng, Ann-Joy ^[3]

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1. Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China)
2. Division of Hematology/Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan (China)
3. Taipei Chang Gung Head and Neck Oncology Group, Chang Gung Memorial Hospital, Taoyuan, Taiwan (China)

Purpose: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Methods and Materials: Four hundred and eight sequential NPC patients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. Results: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. Conclusion: Among our study group of NPC patients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPC patients after radiotherapy. The impact of pituitary injury should be also considered.

• OSTI ID: 21372171
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 76; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
BODY
CARBOXYLIC ACIDS
CARCINOMAS
DIGESTIVE SYSTEM
DISEASES
ENDOCRINE DISEASES
ENDOCRINE GLANDS
GLANDS
HORMONES
HYPOTHYROIDISM
MATHEMATICS
MEDICINE
MULTIVARIATE ANALYSIS
NEOPLASMS
NUCLEAR MEDICINE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PEPTIDE HORMONES
PHARYNX
PITUITARY HORMONES
PROTEINS
RADIOLOGY
RADIOTHERAPY
RESPIRATORY SYSTEM
STATISTICS
THERAPY
THYROID
THYROID HORMONES
THYROXINE
TSH