The role of positron emission tomography/computed tomography in the management of recurrent papillary thyroid carcinoma

Laryngoscope. 2005 Feb;115(2):237-43. doi: 10.1097/01.mlg.0000154725.00787.00.

Abstract

Objectives/hypothesis: The aim of the study was to evaluate the role of combined positron emission tomography/computed tomography (PET/CT) fusion imaging in the detection and management of recurrent papillary thyroid cancer.

Study design: A retrospective analysis of 33 patients with suspected recurrent papillary thyroid carcinoma who had undergone PET/CT was performed. PET/CT was compared with standard imaging techniques in each patient to determine whether PET/CT contributed to the therapeutic management plan. Histopathological findings were correlated to PET/CT in patients who underwent surgery.

Methods: The senior author reviewed the charts of 33 patients with recurrent papillary thyroid carcinoma to determine the impact PET/CT had on management. PET/CT was compared with conventional imaging results. In surgical patients, PET/CT was compared with histopathological findings to determine its sensitivity, specificity, accuracy, positive predictive value, and negative predictive value.

Results: In 67% of the cases (22 of 33), PET/CT supplied additional information that altered or confirmed the management plan. Twenty of 33 patients underwent surgery with 36 sites assessed by histopathological analysis. PET/CT correlated with histopathological findings in 25 of 36 distinct anatomical sites, with an accuracy of 70%. The sensitivity of PET/CT in identifying recurrence was found to be 66%, with a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 27%.

Conclusion: Combined PET/CT fusion scanning was most useful in the detection and management of recurrent papillary thyroid cancer in patients who had average thyroglobulin levels greater than 10 ng/mL and when the tumor no longer concentrated radioactive iodine. In 100% of the cases in which PET/CT localized a region suspicious for malignancy, histopathological analysis confirmed the results. When PET/CT is positive, it is a powerful tool for predicting exact locations of recurrent papillary thyroid cancer, thus making it a reliable guide for surgical planning. PET/CT is a supplement to conventional imaging and fine-needle aspiration in the workup of recurrent papillary thyroid cancer. A negative finding on PET/CT is not sufficiently reliable to preclude further investigation and treatment.

MeSH terms

  • Adult
  • Aged
  • Carcinoma, Papillary / blood
  • Carcinoma, Papillary / diagnostic imaging*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / blood
  • Neoplasm Recurrence, Local / diagnostic imaging*
  • Positron-Emission Tomography*
  • Sensitivity and Specificity
  • Thyroglobulin / blood
  • Thyroid Neoplasms / blood
  • Thyroid Neoplasms / diagnostic imaging*
  • Thyroid Neoplasms / pathology
  • Tomography, X-Ray Computed

Substances

  • Thyroglobulin