title: [Effect of radiotherapy on the thyroid of patients with nasopharyngeal cancer].
abstract: OBJECTIVE
  To determine the effect of radiotherapy on the thyroid of patients with nasopharyngeal cancer.
  
  
  METHODS
  Thyroid dynamic imaging was performed on 51 patients with nasopharyngeal cancer who had the metastasis of the jugular lymph node before and after the radiotherapy. The peak time of the thyroid artery perfusion and the constant K were obtained. The levels of free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) in the blood serum were measured at the same time.
  
  
  RESULTS
  The peak time of the left and right thyroid artery perfusion before the radiotherapy was (14.5+/-2.1)s and (15.1+/-1.9)s, respectively, while that after the radiotherapy was (19.3+/-3.2)s and (20.2+/-3.5)s, respectively. There was significant difference between the pre- and post-radiotherapy (P<0.001). The constant K of the left and right thyroid before the radiotherapy was significantly higher than that after the radiotherapy (0.0265+/-0.0074 vs. 0.0173+/-0.0062; 0.0249+/-0.0065 vs. 0.0167+/-0.0053, P<0.001, respectively). The level of FT3 and FT4 was significantly higher than that after the radiotherapy, but the TSH level had no obvious change[(4.76+/-0.95) pmol/L vs. (3.85+/-0.71) pmol/L,P<0.001; (18.63+/-3.84) pmol/L vs. (15.69+/-3.27) pmol/L,P<0.001; (1.17+/-0.52) mU/L vs. (1.22+/-0.76)mU/L ,P>0.05, respectively].
  
  
  CONCLUSIONS
  The peak time of the thyroid artery perfusion and the constant K which reflect blood stream status after the radiotherapy are all damaged in patients with nasopharyngeal cancer. The level of FT3 and FT4 in the blood serum is dropped but the TSH level has no obvious change.
authors.affiliation: Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha 410008, China. 1004ddhhyy@163.com
authors.forename: Hao-yu
authors.initials: HY
authors.lastname: Deng
authors.forename: Wen-feng
authors.initials: WF
authors.lastname: Chen
authors.forename: Xin-hui
authors.initials: XH
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Hu
authors.forename: Liang-fang
authors.initials: LF
authors.lastname: Shen
authors.forename: You-yi
authors.initials: YY
authors.lastname: Dai
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000097:blood / Q000503:physiopathology* / Q000532:radiotherapy*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000528:radiation effects*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D055815:Young Adult
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine