title: Accuracy of unstimulated Basal serum thyroglobulin levels in assessing the completeness of thyroidectomy.
abstract: BACKGROUND
  Complete excision is important for proper surgical treatment of thyroid disorders. Functional thyroid tissue can be identified based on the level of serum thyroglobulin (Tg), which is produced only by the thyroid follicular cells, and nuclear scan.
  
  
  METHODS
  Serum thyroid stimulating hormone (TSH), free thyroxin (FT4), basal (unstimulated) Tg and anti-Tg antibody (anti-Tg ab) were measured at the sixth postoperative month in 100 patients with benign thyroid disorders treated by total thyroidectomy. Thyroid nuclear scan was obtained to identify functional remnant of the thyroid gland. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the Tg levels in assessing thyroid remnant were calculated.
  
  
  RESULTS
  Positive scan showed thyroid remnant in 23 patients, among whom 16 were Tg positive (true positive) and seven were Tg negative (< 0.5 ng/mL) (false negative). In these patients, the nuclear scan revealed pyramidal lobe remnants. In 77 patients with negative scan, the Tg levels were also negative (true negative), and the PPV, NPV, sensitivity, specificity and accuracy of the Tg levels were 100%, 92%, 70%, 100% and 93%, respectively.
  
  
  CONCLUSIONS
  The positive basal Tg (> 0.5 ng/mL) level accurately indicated the functional thyroid remnant after total thyroidectomy. The negative Tg (< 0.5 ng/mL) level supported complete excision of the thyroid gland. The surgical completeness of total thyroidectomy was accurately evaluated based on the serum Tg levels. Therefore, serum Tg levels should be measured in postoperative follow-up to determine the completeness of total thyroidectomy.
authors.affiliation: Department of Surgery, Faculty of Medicine, Duzce University, Duzce, Turkey.
authors.forename: Emin
authors.initials: E
authors.lastname: Gurleyik
authors.affiliation: Department of Surgery, Faculty of Medicine, Duzce University, Duzce, Turkey.
authors.forename: Sami
authors.initials: S
authors.lastname: Dogan
keywords: Benign disorders; Nuclear scan; Surgery; Thyroglobulin; Thyroid
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