title: Prospective validation of the ultrasound based TIRADS (Thyroid Imaging Reporting And Data System) classification: results in surgically resected thyroid nodules.
abstract: OBJECTIVE
  To assess performance of TIRADS classification on a prospective surgical cohort, demonstrating its clinical usefulness.
  
  
  METHODS
  Between June 2009 and October 2012, patients assessed with pre-operative ultrasound (US) were included in this IRB-approved study. Nodules were categorised according to our previously described TIRADS classification. Final pathological diagnosis was obtained from the thyroidectomy specimen. Sensitivity, specificity, positive/negative predictive values and likelihood ratios were calculated.
  
  
  RESULTS
  The study included 210 patients with 502 nodules (average: 2.39 (±1.64) nodules/patient). Median size was 7 mm (3-60 mm). Malignancy was 0 % (0/116) in TIRADS 2, 1.79 % (1/56) in TIRADS 3, 76.13 % (185/243) in TIRADS 4 [subgroups: TIRADS 4A 5.88 % (1/17), TIRADS 4B 62.82 % (49/78), TIRADS 4C 91.22 % (135/148)], and 98.85 % (86/87) in TIRADS 5. With a cut-off point at TIRADS 4-5 to perform FNAB, we obtained: sensitivity 99.6 % (95 % CI: 98.9-100.0), specificity 74.35 % (95 % CI: 68.7-80.0), PPV 82.1 % (95 % CI: 78.0-86.3), NPV 99.4 % (95 % CI: 98.3-100.0), PLR 3.9 (95 % CI: 3.6-4.2) and an NLR 0.005 (95 % CI: 0.003-0.04) for malignancy.
  
  
  CONCLUSIONS
  US-based TIRADS classification allows selection of nodules requiring FNAB and recognition of those with a low malignancy risk.
  
  
  CONCLUSIONS
  • TIRADS classification allows accurate selection of thyroid nodules requiring biopsy (TIRADS 4-5). • The recognition of benign/possibly benign patterns can avoid unnecessary procedures. • This classification and its sonographic patterns are validated using surgical specimens.
authors.affiliation: Radiology Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile. eleonora.horvath@gmail.com.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Horvath
authors.affiliation: Radiology Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Claudio F
authors.initials: CF
authors.lastname: Silva
authors.affiliation: Internal Medicine Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Sergio
authors.initials: S
authors.lastname: Majlis
authors.affiliation: Medical School, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Rodriguez
authors.affiliation: Medical School, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Velimir
authors.initials: V
authors.lastname: Skoknic
authors.affiliation: Pathology Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Alex
authors.initials: A
authors.lastname: Castro
authors.affiliation: Surgery Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Hugo
authors.initials: H
authors.lastname: Rojas
authors.affiliation: Radiology Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Juan-Pablo
authors.initials: JP
authors.lastname: Niedmann
authors.affiliation: Surgery Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Arturo
authors.initials: A
authors.lastname: Madrid
authors.affiliation: Surgery Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Felipe
authors.initials: F
authors.lastname: Capdeville
authors.affiliation: Radiology Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Carolina
authors.initials: C
authors.lastname: Whittle
authors.affiliation: Surgery Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Rossi
authors.affiliation: Internal Medicine Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Miguel
authors.initials: M
authors.lastname: Domínguez
authors.affiliation: Internal Medicine Department, Clinica Alemana, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Hernán
authors.initials: H
authors.lastname: Tala
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods; D044963:Biopsy, Fine-Needle / Q000379:methods; D005260:Female; D050031:Hashimoto Disease / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods; D013966:Thyroiditis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D014463:Ultrasonography; D019564:Unnecessary Procedures
keywords: Risk classification; Thyroid cancer; Thyroid neoplasm; Thyroid nodule; Ultrasound