title: Preablation 131-I scans with SPECT/CT in postoperative thyroid cancer patients: what is the impact on staging?
abstract: BACKGROUND
  The utility of preablation radioiodine scans for the management of differentiated thyroid cancer remains controversial.
  
  
  OBJECTIVE
  To determine the contribution of preablation Iodine 131 (131-I) planar with single-photon emission computed tomography/computed tomography (SPECT/CT; diagnostic [Dx] scans) to differentiated thyroid cancer staging.
  
  
  METHODS
  Prospective sequential series at university clinic.
  
  
  METHODS
  Using American Joint Committee on Cancer (AJCC) tumor, node, metastasis (TNM) staging, seventh edition 320 patients post-total thyroidectomy were initially staged based on clinical and pathology data (pTN) and then restaged after imaging (TNM). The impact of Dx scans with SPECT/CT on N and M scores, and TNM stage, was assessed in younger, age <45 years, n = 138 (43%), and older, age ≥ 45 years, n = 182 (57%) patients, with subgroup analysis for T1a and T1b tumors.
  
  
  RESULTS
  In younger patients Dx scans detected distant metastases in 5 of 138 patients (4%), and nodal metastases in 61 of 138 patients (44%), including unsuspected nodal metastases in 24 of 63 (38%) patients initially assigned pathologic (p) N0 or pNx. In older patients distant metastases were detected in 18 of 182 patients (10%), and nodal metastases in 51 of 182 patients (28%), including unsuspected nodal metastases in 26 of 108 (24%) patients initially assigned pN0 or pNx. Dx scans detected distant metastases in 2 of 49 (4%) T1a, and 3 of 67 (4.5%) T1b patients.
  
  
  CONCLUSIONS
  Dx scans detected regional metastases in 35% of patients, and distant metastases in 8% of patients. Information acquired with Dx scans changed staging in 4% of younger, and 25% of older patients. Preablation scans with SPECT/CT contribute to staging of thyroid cancer. Identification of regional and distant metastases prior to radioiodine therapy has significant potential to alter patient management.
authors: Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109-5028, USA. ancaa@med.umich.edu
authors: Anca M
authors: AM
authors: Avram
authors: Lorraine M
authors: LM
authors: Fig
authors: Kirk A
authors: KA
authors: Frey
authors: Milton D
authors: MD
authors: Gross
authors: Ka Kit
authors: KK
authors: Wong
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000175:diagnosis / Q000556:secondary / Q000601:surgery; D018249:Adenoma, Oxyphilic; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000175:diagnosis / Q000556:secondary* / Q000601:surgery*; D002291:Carcinoma, Papillary; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000556:secondary* / Q000601:surgery*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes