Frequency of autonomous function in thyroid nodules in need of FNA according to ATA, EU- and ACR-TIRADS in patients with normal TSH values

Ziel/Aim:

To determine the fraction of nodules in need of FNA according to ATA, EU- or ACR-TIRADS, in which risk of malignancy might be significantly lowered by demonstration of autonomous function by thyroid scintigraphy in patients with normal TSH values form a population with a history of iodine deficiency.

Methodik/Methods:

639 consecutive patients with normal TSH values who presented for the workup of thyroid nodules > 1 cm, including sonography and scintigraphy, between September 2013 and February 2018 were included in this retrospective study. All nodules were categorized into the respective ATA, EU- or ACR-TIRADS categories on grounds of sonographic appearance. The fraction of nodules in need of FNA according to the respective classification system with autonomous function in scintigraphy was then calculated.

Ergebnisse/Results:

68.4% of patients were females and 31.6% male. Mean TSH value was 1.39 ± 0.84µU/ml with 16.1% of patients receiving L-Thyroxin substitution. 1210 nodules > 1 cm were detected. Autonomous function was found by scintigraphy in 34 of 591 (5,7%) nodules in need for FNA according to ATA, 24 of 357 (6.7%) according to EU-TIRADS and 14 of 215 (6.5%) according to ACR-TIRADS.

Schlussfolgerungen/Conclusions:

Thyroid scintigraphy demonstrates autonomous function in a relevant number of nodules in need of FNA according to ATA, EU- or ACR-TIRADS in patients with normal TSH values. Therefore, thyroid scintigraphy might significantly lower the risk of malignancy in those nodules and could can avoid unnecessary lobectomy, especially when FNA is not possible or inconclusive.