Sonography in the diagnosis of cervical recurrence in patients with differentiated thyroid carcinoma

Objective. To determine the sensitivity of thyroglobulin (Tg), iodine scanning, and sonography in the diagnosis of cervical recurrence of thyroid cancer Methods. This prospective study assessed 81 patients with cervical metastases or extrathyroid invasion at first appearance who underwent clinical examination, scanning, measurement of Tg after thyroxine withdrawal, and sonography about 8 months after thyroidectomy followed by radioiodine treatment. Only patients without distant metastases and without anti-Tg antibodies were included. Results. Fifty patients showed persistence of the disease in the cervical region, with only 16% of them having had a suspicion on clinical examination, 33 with Tg levels of 2 ng/mL or greater (66% sensitivity), and 29 with positive scan findings (58% sensitivity). A combination of the 2 methods detected disease in 40 (80%) of 50 patients but failed to show 20% of cases that were identified by sonography and confirmed by fine-needle aspiration. Sonography had sensitivity of 96%. Specificity values for Tg, iodine scanning, and sonography were 80.6%, 90.3%, and 87%, respectively. Conclusions. Classic follow-up methods may not detect cervical disease in some patients with differentiated thyroid carcinoma, and sonography is necessary even in patients apparently free of the disease.