Hemithyroidectomy Versus Total Thyroidectomy in the Intermediate-risk Differentiated Thyroid Cancer: the Italian Societies of Endocrine Surgeons and Surgical Oncology Multicentric Study

The surgical treatment of the intermediate-risk DTC (1-4 cm) remains still controversial. We analyzed the current practice in Italy regarding the surgical management of intermediate-risk unilateral DTC to evaluate risk factors for recurrence and to identify a group of patients to whom propose a total thyroidectomy (TT) vs. hemithyroidectomy (HT). Among 1896 patients operated for thyroid cancer between January 2017 and December 2019, we evaluated 564 (29.7%) patients with unilateral intermediate-risk DTC (1-4 cm) without contralateral nodular lesions on the preoperative exams, chronic autoimmune thyroiditis, familiarity or radiance exposure. Data were collected retrospectively from the clinical register from 16 referral centers. The patients were followed for at least 14 months (median time 29.21 months). In our cohort 499 patients (88.4%) underwent total thyroidectomy whereas 65 patients (11.6%) underwent hemithyroidectomy. 151 (26.8%) patients had a multifocal DTC of whom 57 (10.1%) were bilateral. 21/66 (32.3%) patients were reoperated within 2 months from the first intervention (completion thyroidectomy). Three patients (3/564) developed regional lymph node recurrence 2 years after surgery and required a lymph nodal neck dissection. The single factor related to the risk of reoperation was the histological diameter (HR = 1.05 (1.00-1-09), p = 0.026). Risk stratification is the key to differentiating treatment options and achieving better outcomes. According to the present study, tumor diameter is a strong predictive risk factor to proper choose initial surgical management for intermediate-risk DTC.