title: Frequent visualization of thyroglossal duct remnant on post-ablation 131I-SPECT/CT and its clinical implications.
abstract: OBJECTIVE
  To evaluate the frequency of thyroglossal duct remnant (TGDR) uptake on post-therapy (131)I-scintigraphy in thyroid cancer patients, to analyse the rate of persistent TGDR uptake on follow-up combined (131)I-single-photon emission CT/CT (SPECT/CT), and to identify the differential clinical characteristics between patients with positive and negative TGDR uptake on (131)I-SPECT/CT.
  
  
  METHODS
  A total of 179 patients treated with total thyroidectomy for thyroid cancer were enrolled in the study. At (131)I-whole-body scan (WBS), TGDR uptake was defined as an increase in radioactivity at the midline of the neck versus the thyroid bed. TGDR uptake on (131)I- SPECT/CT was defined as the presence of radioactivity at the expected pathway of the thyroglossal duct without evidence of metastatic foci. Persistent TGDR uptake was confirmed when TGDR uptake on follow-up (131)I-SPECT/CT corresponded to previous TGDR uptake detected by post-therapy (131)I-SPECT/CT.
  
  
  RESULTS
  At SPECT/CT, TGDR uptake was noted in 86 of 179 patients. Stimulated thyroglobulin (sTg) levels were significantly higher (p = 0.02) in patients with positive TGDR uptake. Persistent TGDR uptake on follow-up (131)I-SPECT/CT was noted in 15 of 86 patients; sTg levels were significantly higher (p = 0.03) in the patients with persistent TGDR uptake.
  
  
  CONCLUSIONS
  TGDR uptake is frequently visualized on post-therapy (131)I-SPECT/CT images and can be resistant to (131)I ablation. TGDR uptake has the potential to result in an elevation of serum thyroglobulin levels. (131)I-SPECT/CT clarifies TGDR uptake without additional invasive procedures or imaging studies, eliminating confusion among clinicians for managing differentiated thyroid cancer patients.
authors.affiliation: Department of Nuclear Medicine, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea.
authors.forename: M
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Y K
authors.initials: YK
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: T J
authors.initials: TJ
authors.lastname: Jeon
authors.affiliation: Thyroid Cancer Center, Department of Surgery, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: H S
authors.initials: HS
authors.lastname: Chang
authors.affiliation: Thyroid Cancer Center, Department of Surgery, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: B-W
authors.initials: BW
authors.lastname: Kim
authors.affiliation: Thyroid Cancer Center, Department of Surgery, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Thyroid Cancer Center, Department of Surgery, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: C S
authors.initials: CS
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea. Electronic address: ryuyh@yuhs.ac.
authors.forename: Y H
authors.initials: YH
authors.lastname: Ryu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017115:Catheter Ablation / Q000379:methods; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual; D019275:Radiopharmaceuticals; D013955:Thyroglossal Cyst / Q000000981:diagnostic imaging; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals