Keywords:
Head and neck, PET-CT, Ultrasound, Puncture, Neoplasia
Authors:
C. Alvarez Sánchez1, S. Merino1, M. J. Fernández-Aceñero1, R. Valhondo Rama1, A. VIDAL GONZÁLEZ1, E. Bello Martínez1, T. Ganado Diaz2; 1Madrid/ES, 2Madrid /ES
DOI:
10.26044/ecr2019/C-2146
Aims and objectives
Thyroid incidentalomas are nonpalpable thyroid nodules defined as newly identified thyroid lesions encountered during imaging procedures,
mainly on PET-CT.
The uptake of the FDG in the normal thyroid gland is homogenous and of low intensity and is usually not visualized on a PET-CT. Focal or diffuse FDG uptake in the thyroid gland is often seen as an incidental finding and most thyroid nodules are identified incidentally and less often by palpation.
These nonpalpable nodules have approximately the same risk of malignancy as palpable nodules.
The current guidelines for thyroid nodules have not established specific management plans for thyroid incidentalomas on PET-TC.
Thyroid cancer is the most common endocrine cancer.
Focal FDG uptake in the thyroid has a reported incidence of 0.2–8.9% with a malignancy risk of 8–64%.
These and other reported percentages on the literature have a very wide range; so the risk of thyroid cancer in these nodules is very variable and the significance and value of incidental diffuse and focal thyroid FDG uptake is discussed.
For example,
it is controversial whether the semiquantified index maximal standardized uptake value (SUVmax) can differentiate between malignant and benign thyroid nodules.
The main aim of this study is to characterize the relationship between the 18F-fluorodeoxyglucose uptake on thyroid nodules incidentally detected on PET-TC and the risk for malignance and to stablish,
if possible,
a SUVmax number that may suggest an increased risk for malignancy.
Previous studies have evaluated the utility of ultrasound features for the evaluation of thyroid incidentalomas detected on PET-TC demonstrating that the risk of malignancy varies according to the ultrasound features.
The risk of malignancy is lower when ultrasound features appear to be benign rather than suspicious,
also when thyroid nodules are detected on PET-CT.
We studied ultrasonographic characteristics of incidental thyroid nodules and correlated with malignancy in order to,
in a future,
avoid FNA procedures when these characteristics were typically benign.