title: Clinical relevance of single-photon emission computed tomography/computed tomography of the neck and thorax in postablation (131)I scintigraphy for thyroid cancer.
abstract: BACKGROUND
  In patients with differentiated thyroid carcinoma, postablation (131)I scintigraphy aims to detect residual neck disease and distant metastases, usually found in lungs and bones. New hybrid single-photon emission computed tomography/computed tomography (SPECT-CT) cameras that permit functional and anatomical image fusion may improve its clinical relevance.
  
  
  OBJECTIVE
  Our objective was to test the added value of neck and thorax SPECT-spiral CT to whole-body scan (WBS) in postablation (131)I scintigraphy.
  
  
  METHODS
  This was a single-referral-center prospective study with a median follow-up of 21 months.
  
  
  METHODS
  Postablation (131)I WBS and neck and thorax SPECT-CT were performed in 55 consecutive patients treated in 2006. WBS and SPECT-CT data were blindly reviewed, scored negative (benign), positive (malignant), or indeterminate and were correlated to the patient outcome.
  
  
  RESULTS
  At patient level, WBS and SPECT-CT were negative in 67 and 78% of patients, positive in 4 and 15%, and indeterminate in 29 and 7%, respectively. Overall, nine patients (16%) presented treatment failure (persistent or recurrent disease) 1-16 months after radioiodine ablation. In the 16 patients with indeterminate WBS, negative SPECT-CT ruled out suspicion of disease in nine of nine patients, and positive SPECT-CT confirmed malignant lesions in four of five patients. Positive SPECT-CT predicted treatment failure better than positive WBS (McNemar's test, P = 0.03).
  
  
  CONCLUSIONS
  This study demonstrates the complementary role of neck and thorax SPECT-CT to WBS in postablation (131)I scintigraphy. Because SPECT-CT allows one to confirm or to rule out residual disease in most cases where WBS remains indeterminate, we recommend its use when available.
authors.affiliation: Department of Nuclear Medicine and Thyroid Unit, Centre François Baclesse, F-14076 Caen Cedex 05, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Aide
authors.forename: Natacha
authors.initials: N
authors.lastname: Heutte
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Rame
authors.forename: Elise
authors.initials: E
authors.lastname: Rousseau
authors.forename: Cédric
authors.initials: C
authors.lastname: Loiseau
authors.forename: Michel
authors.initials: M
authors.lastname: Henry-Amar
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bardet
mesh_terms: D055011:Ablation Techniques / Q000379:methods; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000601:surgery; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging*; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011379:Prognosis; D012189:Retrospective Studies; D013909:Thorax / Q000000981:diagnostic imaging*; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D051598:Whole Body Imaging / Q000379:methods; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes