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.