title: Clinical outcomes of persistent radioiodine uptake in the neck shown by diagnostic whole body scan in patients with differentiated thyroid carcinoma after initial surgery and remnant ablation.
abstract: OBJECTIVE
  To evaluate the clinical outcomes of persistent radioiodine uptake (RAIU) in the neck by diagnostic whole body scan (DxWBS) after initial therapy and the efficacy of the second ablation in patients with differentiated thyroid carcinoma (DTC).
  
  
  METHODS
  Patients with DTC who underwent bilateral surgery and high-dose remnant ablation between 2000 and 2004 were included. Patients with elevated serum stimulated thyroglobulin (sTg) or extensive lateral neck lymph node involvement at initial surgery underwent a second ablation, and patients with undetectable sTg or in very low-risk groups were observed.
  
  
  RESULTS
  Among 572 patients, 25 had persistent RAIU in the neck at first DxWBS. After a median 65.7 months of follow-up, five of these patients (20%) had persistent disease, whereas another 20 patients had no abnormal findings by ultrasonography (US) or other imaging modalities. Seven of 20 patients underwent second ablation and 13 were observed. RAIU disappeared spontaneously in about half of the patients in the observation group. There were no significant between-group differences in change of RAIU at follow-up DxWBS (P = 0.62). Serum sTg decreased and eventually disappeared over a few years in both groups. Ablation failure was not an independent risk factor for recurrence (P = 0.169).
  
  
  CONCLUSIONS
  Neck US and serum sTg, but not DxWBS, were useful diagnostic tools during follow-up of patients with persistent uptake in the neck at DxWBS. A second ablation was not necessary when neck US showed no evidence of disease, especially in patients with very low sTg concentration.
authors.affiliation: Department of Endocrinology & Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Seoul 138-736, Korea.
authors.forename: Eui Young
authors.initials: EY
authors.lastname: Kim
authors.forename: Won Gu
authors.initials: WG
authors.lastname: Kim
authors.forename: Won Bae
authors.initials: WB
authors.lastname: Kim
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Kim
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Ryu
authors.forename: Gyungyub
authors.initials: G
authors.lastname: Gong
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Yoon
authors.forename: Suck Joon
authors.initials: SJ
authors.lastname: Hong
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Baek
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Shong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D002454:Cell Differentiation; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009333:Neck; D018365:Neoplasm, Residual; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D051598:Whole Body Imaging; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes