Evaluation of Thyroid Bed Nodules on Ultrasonography after Total Thyroidectomy: Risk for Loco-Regional Recurrence of Thyroid Cancer

Abstract

Objectives: We conducted a retrospective chart review of patients with differentiated thyroid cancer who underwent total thyroidectomy to examine the correlation of the persistence of thyroid bed nodules seen on ultrasonography with subsequent loco-regional recurrence. Methods: A total of 60 patients with differentiated thyroid cancer were identified who underwent total thyroidectomy, received ¹³¹I therapy and had thyroid bed nodules on postoperative surveillance ultrasonography. The ultrasonographic features of the thyroid bed nodules and their progression over time along with serum thyroglobulin (Tg) levels were monitored. Those patients who demonstrated no evidence of recurrence were compared to patients who had recurrence. Results: Of the 60 patients, 25% had documented cancer recurrence. Sixty percent of the patients in the recurrence group had an increase in the size of bed nodules as compared to only 7% of the patients in the group without recurrence. An increase in serum Tg of more than 2-fold was seen in 80% of the patients with recurrence and in only 13% (6/45) of the patients without cancer recurrence. The odds of identifying recurrent thyroid cancer in patients with more than a 2-fold increase in serum Tg were 80.5 greater than in patients with a less than 2-fold increase in serum Tg. The odds of identifying recurrent thyroid cancer in patients with the presence of any suspicious thyroid bed nodule were 31.5 times greater than in patients without suspicious thyroid bed nodules. Conclusions: Thyroid bed nodules on surveillance ultrasound warrant fine-needle aspiration cytology if they increase in size and number, are persistent and associated with suspicious sonographic features.