Prognostic role of 18F-FDG PET/CT in the postoperative evaluation of differentiated thyroid cancer patients

Leonardo Pace, Michele Klain, Barbara Salvatore, Emanuele Nicolai, Emilia Zampella, Roberta Assante, Teresa Pellegrino, Giovanni Storto, Rosa Fonti, Marco Salvatore

Research output: Contribution to journalArticle

Abstract

PURPOSE: The aim of this study was to evaluate the role of 18F-FDG PET/CT performed after surgery but before radioiodine therapy in patients with differentiated thyroid cancer. PROCEDURES: FDG PET/CT was performed off l-thyroxine in 60 newly diagnosed differentiated thyroid cancer patients. Clinical and hematological evaluation as well as high-resolution neck ultrasound were performed. All patients underwent a complete follow-up (range, 6-67 months; mean [SD], 31.7 [20.6] months). The date of recurrence or the most recent office visit was recorded. Progression-free survival (PFS) is the primary end point of this study. Analysis was performed by Cox proportional hazards model. Survival curves were generated using Kaplan-Meier estimates, and the log-rank test was used to assess significance. RESULTS: FDG PET/CT was negative in 63% of patients, 20% had FDG thyroid bed uptake, 5% distant metastases, and 12% lymph node FDG uptake. In patients with positive FDG PET/CT scan (ie, those with distant metastases or lymph node uptake), a higher rate of recurrence was observed (50% vs 6%, P <0.05). Thyroglobulin, neck ultrasound, stage, and FDG PET/CT correlated with PFS at univariate analysis. At multivariate analysis, only thyroglobulin and FDG PET/CT continued to be predictors of PFS. Patients with a negative FDG PET/CT scan have a better PFS either in the whole group or in those with elevated thyroglobulin level (both >2 ng/mL and >10 ng/mL). CONCLUSIONS: FDG PET/CT was abnormal in 17% of patients. Moreover, FDG PET/CT has an independent prognostic role, with a better PFS in patients with a negative scan.

Original languageEnglish
Pages (from-to)111-115
Number of pages5
JournalClinical Nuclear Medicine
Volume40
Issue number2
DOIs
Publication statusPublished - Feb 21 2015

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Keywords

  • differentiated thyroid cancer
  • FDG PET/CT
  • progression-free survival

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Medicine(all)

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