title: Analysis of Clinical Factors for the Determination of Optimal Serum Level of Thyrotropin After Recombinant Human Thyroid-Stimulating Hormone Administration.
abstract: OBJECTIVE
  To determine the optimal levels of thyroid-stimulating hormone (TSH) levels after administration of recombinant human TSH (rhTSH) to patients with differentiated thyroid cancer (DTC), we have analyzed the clinical parameters that affected the degree of the increase in serum levels of TSH.
  
  
  METHODS
  We retrospectively analyzed 276 patients with differentiated thyroid cancer (DTC), post-thyroidectomy and remnant ablation. Pearson's correlation coefficient test was used to evaluate the correlation between serum levels of TSH after rhTSH stimulation and various clinical factors, including age, sex, height, weight, body mass index (BMI), body surface area (BSA), serum blood urea nitrogen, creatinine, and estimated glomerular filtration rate (GFR). Linear regression analysis was used to determine the predictors of the degree of increase in serum TSH level after rhTSH stimulation.
  
  
  RESULTS
  After the rhTSH injections, all subjects achieved TSH levels of >30 μU/mL, with a mean of 203.8 ± 83.4 μU/mL. On univariate analysis, age (r = 0.255) and serum creatinine (r = 0.169) level were positive predictors for higher levels of serum TSH after rhTSH stimulation, while weight (r = -0.239), BMI (r = -0.223), BSA (r = -0.217), and estimated GFR (r = -0.199) were negative predictors. Multiple linear regression analysis revealed that serum creatinine was the most powerful independent predictor for serum levels of TSH, followed by age, BSA, and BMI.
  
  
  CONCLUSIONS
  An increment in serum TSH after rhTSH stimulation was significantly affected by age, BSA, BMI, and creatinine, with creatinine being the most powerful predictor. By understanding the difference in the increased levels of TSH in various subjects, their dose of rhTSH can be adjusted during scheduling for radioiodine ablation, or during follow-up (recurrence surveillance) after surgery and ablation.
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Son
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Choon-Young
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Do-Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Shin Young
authors.initials: SY
authors.lastname: Jeong
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Byeong-Cheol
authors.initials: BC
authors.lastname: Ahn
authors.affiliation: Department of Nuclear Medicine, Kyungpook National University Medical Center and School of Medicine, 50 Samduk-dong 2-ga, Jung-gu, Daegu 700-721 Republic of Korea.
authors.forename: Jaetae
authors.initials: J
authors.lastname: Lee
keywords: Differentiated thyroid cancer; Recombinant human thyroid-stimulating hormone; RhTSH; Thyroid cancer; Thyrotropin