title: Correlative study of dose to thyroid and incidence of subsequent dysfunction after head and neck radiation.
abstract: Thyroid dysfunction is common after radiotherapy (RT) for patients with head and neck cancers. We attempted to discover RT dose parameters that correspond with RT-induced thyroid dysfunction.
  
  
  
  Records of 102 patients who received RT from 2008 to 2010 were reviewed with respect to thyroid function. Abnormalities were grouped in 2 ways: (1) none, transient, or permanent; and (2) overt or subclinical.
  
  
  
  At median follow-up of 33.5 months, incidence of any thyroid abnormality was 39.2% (women vs men - 50% vs 35%). Permanent dysfunction was seen in 24.5% with higher incidence in women versus men (42.9% vs 17.6%; p = .0081). Permanent abnormalities most strongly correlated with D50%(p = .0275). V50Gyalso correlated with thyroid dysfunction post-RT (p = .0316). Concurrent chemotherapy increased permanent dysfunction (p = .0008).
  
  
  
  Achieving D50%<50 Gy, V50<50%, and mean dose <54.58 Gy during RT planning may decrease the incidence; whereas female sex and concurrent chemotherapy seem to increase the risk of RT-induced hypothyroidism. © 2016 Wiley Periodicals, Inc. Head Neck 39: 548-554, 2017.
authors.affiliation: Department of Radiation Oncology, The Ohio State University, Columbus, Ohio.
authors.forename: Stella
authors.initials: S
authors.lastname: Ling
authors.affiliation: Department of Radiation Oncology, The Ohio State University, Columbus, Ohio.
authors.forename: Aashish D
authors.identifier: 0000-0002-8233-7920
authors.initials: AD
authors.lastname: Bhatt
authors.affiliation: Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio.
authors.forename: Nicole V
authors.initials: NV
authors.lastname: Brown
authors.affiliation: Department of Radiation Oncology, The Ohio State University, Columbus, Ohio.
authors.forename: Phuong
authors.initials: P
authors.lastname: Nguyen
authors.affiliation: Department of Endocrinology, The Ohio State University, Columbus, Ohio.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Sipos
authors.affiliation: Department of Radiation Oncology, The Ohio State University, Columbus, Ohio.
authors.forename: Arnab
authors.initials: A
authors.lastname: Chakravarti
authors.affiliation: Department of Radiation Oncology, The Ohio State University, Columbus, Ohio.|Department of Radiation Oncology, University of California - Davis Comprehensive Cancer Center, Sacramento, California.
authors.forename: Yi
authors.initials: Y
authors.lastname: Rong
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D016009:Chi-Square Distribution; D015331:Cohort Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011832:Radiation Injuries / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D011878:Radiotherapy / Q000009:adverse effects* / Q000379:methods; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D013959:Thyroid Diseases / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology / Q000528:radiation effects; D016896:Treatment Outcome
keywords: head and neck radiotherapy; hypothyroidism; radiation dose volume histogram (DVH); radiation toxicity; thyroid abnormality