title: Hypothyroidism after radiotherapy for primary thyroid lymphoma.
abstract: BACKGROUND
  Thyroid lymphoma is rare, with no standard therapeutic protocol. Radiotherapy is often employed.
  
  
  METHODS
  Nine patients who had received radiotherapy for thyroid lymphoma in our Institute, from September 2005 to August 2013, were reviewed for hypothyroidism. The median radiation dose was 40 Gy. Thyroid-stimulating hormone (TSH) levels were measured before and after radiotherapy, and hypothyroidism was defined as a TSH level exceeding 10 mIU/l. Peak TSH was defined as the highest TSH level during the follow-up period.
  
  
  RESULTS
  The complete response rate was 77.8%, and the 5-year overall survival rate was 74.1%. The median time-to-peak TSH was 162.5 days after the start of radiotherapy. Hypothyroidism was diagnosed in three (37.5%) out of eight patients without thyroidectomy.
  
  
  CONCLUSIONS
  Hypothyroidism is a frequent complication of radiotherapy for thyroid lymphoma.
authors: Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan ishibashi.naoya@nihon-u.ac.jp.
authors: Naoya
authors: N
authors: Ishibashi
authors: Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan.
authors: Toshiya
authors: T
authors: Maebayashi
authors: Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan.
authors: Takuya
authors: T
authors: Aizawa
authors: Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan.
authors: Masakuni
authors: M
authors: Sakaguchi
authors: Department of Radiology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan.
authors: Osamu
authors: O
authors: Abe
authors: Radiology Clinic, Sonoda Medical Corporations, Adachi-ku, Tokyo, Japan.
authors: Tsutomu
authors: T
authors: Saito
authors: Department of Radiation Oncology, St. Luke's International Hospital, Chuo-ku, Tokyo, Japan.
authors: Jiro
authors: J
authors: Kawamori
authors: Department of Radiation Oncology, Kawasaki Saiwai Hospital, Kawasaki, Kanagawa, Japan.
authors: Yoshiaki
authors: Y
authors: Tanaka
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000209:etiology*; D008223:Lymphoma / Q000401:mortality / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011878:Radiotherapy / Q000009:adverse effects; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D013972:Thyrotropin / Q000097:blood
chemical_list: D013972:Thyrotropin
keywords: Thyroid; hypothyroidism; malignant lymphoma; radiotherapy; thyrotropin