Focal Uptake of Fluorodeoxyglucose by the Thyroid in Patients Undergoing Initial Disease Staging with Combined PET/CT for Non–Small Cell Lung Cancer

Abstract

Focal thyroid FDG uptake found during the initial staging of NSCLC at PET/CT indicates a high likelihood of primary thyroid cancer.

The Significance and Management of Incidental [18F]Fluorodeoxyglucose–Positron-Emission Tomography Uptake in the Thyroid Gland in Patients with Cancer

“…This finding is comparable with what was previously reported in the literature. [1][2][3][4][5][6][7] Similar to previous reports, 1,2,6,7 we found a high (27.8%) risk for malignant tumors in patients with incidentally identified focal FDG-PET uptake in the thyroid gland.…”

“…[1][2][3][4][5][6] In our patients, the mean SUV max was 2.9 for the benign lesions and 3.4 for the malignant lesions, without a statistical difference between these groups (P Ͼ .05). This finding is similar to that of a previous report by Kim et al 6 The risk for malignant disease in any thyroid nodule is in the range of 4% to 5%, 12,13 and nodules found incidentally on carotid Doppler studies, MR imaging studies, and CT scans carry a similar risk for malignant disease.…”

“…Several other retrospective studies have reported the incidence of incidentally identified thyroid lesions on FDG-PET to be 1.1% to 4.3%, with a risk for a malignant process ranging from 14% to 50%. [2][3][4][5][6][7] Although the incidence of these lesions is increasing, determining the most appropriate management represents a challenge for endocrinologists and head and neck surgeons. To date, no specific guidelines exist to define which lesions necessitate surgical management.…”

“…Although diffuse thyroid uptake in FDG-PET is believed to be either a normal variant, chronic thyroiditis, or Graves disease, focal thyroid lesions have been associated with a high risk for malignant tumors. [1][2][3][4][5][6][7][8][9][10] Unfortunately, no definitive studies have identified specific characteristics that increase the likelihood of a malignant tumor. Although standard uptake values (SUV max ) has been introduced to predict malignant potential, investigators are still divided regarding this issue.…”

“…Although standard uptake values (SUV max ) has been introduced to predict malignant potential, investigators are still divided regarding this issue. Choi et al and others [1][2][3][4][5] reported a correlation between an elevated SUV max value and a thyroid malignant tumor. However, Kim et al 6 did not find any significant difference in the maximal SUV max value between benign and malignant thyroid nodules on FDG-PET and suggested mandatory cytologic diagnosis regardless of the SUV max .…”