Value of thyroid incidentalomas on positron emission tomographic scans among thyroidectomy patients

To evaluate the preoperative predictive value of a positive positron emission tomographic (PET) scan with respect to malignancy in future thyroidectomy candidates, particularly when the fine-needle aspiration biopsy (FNAB) results in indeterminate findings, and to establish the efficiency with which this can be incorporated as a preoperative marker and potentially contribute to a standardized scoring system for thyroid nodule patients.

This retrospective study examined 1048 thyroidectomy patients, of whom 45 underwent PET with computed tomography for unrelated reasons, among which 13 results were focally positive. The final pathology was evaluated and compared to this result to determine the correlation.

All patients with positive PET results were shown postthyroidectomy to have a thyroid malignancy (13 of 13), corresponding to a positive predictive value of 100%. There was no correlation between a negative PET scan and malignancy, however. When integrating the PET scan criteria in the McGill Scoring System, 4 of these 13 were shifted into a high chance of malignancy group, allowing a more accurate assessment of their risk than they might have previously received.

In comparison with previous data, our results indicate a strong relationship between a positive PET scan and malignancy. If available and used in conjunction with the other preoperative diagnostic tools (outlined by the McGill Thyroid Nodule Scoring System), this test can hold significant merit in determining a therapeutic strategy, particularly in the face of an indeterminate FNAB.