A Prospective Study Showing an Excellent Response of Patients with Low-Risk Differentiated Thyroid Cancer Who Did Not Undergo Radioiodine Remnant Ablation after Total Thyroidectomy

Abstract

Objectives: To prospectively evaluate the outcome of patients with low-risk papillary thyroid carcinoma treated with total thyroidectomy (TT) who did not undergo radioiodine remnant ablation (RRA). Study Design: We prospectively followed up 57 patients; 3 months after TT, thyroglobulin (Tg) assessment and neck ultrasonography (US) were performed while patients were taking <smlcap>L</smlcap>-T₄, presenting suppressed TSH. Six months after TT, patients underwent stimulated Tg testing and whole-body scan (WBS) after recombinant TSH (rhTSH). Then, 18 months after TT, the patients were evaluated by neck US and Tg under TSH between 0.5 and 2.0 mIU/ml. Two years after TT, we performed another rhTSH assessment, measuring Tg and making a WBS. The patients were then annually monitored with neck US and Tg measurement under TSH between 0.5 and 2.0 mIU/l for 36-84 months. Results: Neck US of all patients, 3 months after TT, presented no evidence of abnormal residual tissues or metastatic lymph nodes (negative neck US); at this time, the mean Tg level was 0.42 ng/ml. Six months after surgery, after rhTSH, the mean thyroid bed uptake was 1.82%, and Tg levels ranged from 0.10 to 22.30 ng/ml (mean, 2.89 ng/ml). The patients were followed up without any sign of recurrence (negative neck US and stable or decreasing Tg levels). During the ongoing follow-up, the Tg trend was stable or decreasing, independently of the initial suppressed or stimulated Tg level, or WBS uptake. Conclusions: In patients with low-risk differentiated thyroid cancer, who were operated by TT and who did not undergo RRA, an excellent response to treatment may be confirmed by annual neck US and Tg trend.