Contribution of ultrasound examination in the detection of neck recurrence in low-risk differentiated thyroid carcinoma patients at first follow-up visits.

BACKGROUND In the most patients with differentiated thyroid carcinoma (DTC), recurrent disease occurs in the neck region, but the usefulness of neck ultrasound (US) in its diagnosis is not clear. The aim of this study was to evaluate the significance of US in the detection of neck recurrence in low-risk DTC patients at first follow-up visits. MATERIAL AND METHODS A total of 32 patients, who had a history of DTC and radioiodine therapy after thyroidectomy with low doses of iodine 131 (3.7 GBq), were enrolled in this study. About 6 months after first ablation, the patients underwent clinical examination, iodine 131 scanning, measurement of thyroglobulin (Tg) after T4 withdrawal, thyroid-stimulating hormone measurement, TgAb measurement, and neck sonography with US. RESULTS Recurrence of thyroid cancer was suspected in the neck region in 17 patients (53.1%) of the study cohort. There were six groups based on the results of posttreatment serum Tg levels, 131I whole body scan (131I WBS), and US in the detection of DTC neck recurrences. Fifteen patients had negative results of three modalities (group 1); seven patients had US evidence of neck lesions but negative 131I WBS and serum Tg results(group 2); three patients had positive results of 131I WBS but negative US and serum Tg results (group 3); four patients had positive results of serum Tg results but negative US and 131I WBS results (group 4); two patients lacked 131I WBS evidence of neck lesions, but US and serum Tg suggested the diagnosis of neck recurrence (group 5), and one subject had evidence of neck recurrence in three modalities (group 6). CONCLUSION These findings may imply that neck sonography together with determination of serum Tg levels and 131I WBS after thyroid-stimulating hormone therapy should be considered the diagnostic modality of choice for postoperative surveillance, even in low-risk DTC patients.