title: Radioactive iodine scanning is not beneficial but its use persists for euthyroid patients.
abstract: BACKGROUND
  Radioactive iodine (RAI) scanning is a method of determining the functional status of thyroid nodules. Historically, practitioners thought "cold" or inactive nodules were more likely malignant. However, surgeons no longer find these scans helpful for preoperative management of euthyroid patients. The purpose of this study was to evaluate the utility of RAI scans.
  
  
  METHODS
  We retrospectively reviewed cases of euthyroid patients (thyroid-stimulating hormone > 1.0 mIU/L) who underwent RAI scans before thyroid surgery at our institution between 1994 and 2011. We correlated the RAI scan results with final pathology. We considered RAI scans concordant with pathology when we found a malignancy on the same lobe as a cold nodule. We also tabulated the specialty and affiliation of the ordering physicians.
  
  
  RESULTS
  A total of 109 euthyroid patients underwent RAI scanning as part of their preoperative workup. Of these, 88 patients (81%) had a cold nodule. A malignancy concordant with the RAI scan findings occurred in only 15 of these patients (17%). Non-surgical specialties ordered 90 scans (95%). Only 11 of these scans (10%) were performed in the past 5 y, and physicians outside the academic institution ordered all 11 (100%) of these. A linear regression of RAI scanning per year yielded a slightly negative slope (m-0.32 per year).
  
  
  CONCLUSIONS
  Radioactive iodine scanning is not useful for the surgical management of thyroid disease in euthyroid patients because it poorly predicts malignancy. The overall use of RAI scans is trending downward, but they are still ordered by non-surgical referring physicians.
authors.affiliation: Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, Madison, Wisconsin 53792, USA.
authors.forename: Rajarajan
authors.initials: R
authors.lastname: Panneerselvan
authors.forename: David F
authors.initials: DF
authors.lastname: Schneider
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Sippel
authors.forename: Herbert
authors.initials: H
authors.lastname: Chen
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000097:blood / Q000000981:diagnostic imaging / Q000601:surgery; D018249:Adenoma, Oxyphilic; D002277:Carcinoma / Q000097:blood / Q000000981:diagnostic imaging* / Q000601:surgery*; D018278:Carcinoma, Neuroendocrine; D002291:Carcinoma, Papillary; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000601:surgery*; D016606:Thyroid Nodule / Q000097:blood / Q000000981:diagnostic imaging* / Q000601:surgery*; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood; D019564:Unnecessary Procedures
chemical_list: D007457:Iodine Radioisotopes; D013972:Thyrotropin
keywords: Euthyroid; Radioactive iodine scan; Thyroid nodules