Extent of thyroidectomy: When should hemithyroidectomy be performed? Recommendations from the Francophone Association for Endocrine Surgery, the French Society of Endocrinology and the French Society of Nuclear Medicine.

These recommendations, drawn from current data in the medical literature, incorporate the risks of hemithyroidectomy (HT) and total thyroidectomy (TT) and clarify the place of these two procedures in clinical settings. Discussions leading to a consensus were then assessed by the Francophone Association for Endocrine Surgery (Association francophone de chirurgie endocrinienne [AFCE]), along with the French Society of Endocrinology (Société française d'endocrinologie [SFE]), and the French Society of Nuclear Medicine (Société française de médecine nucléaire [SFMN]). The complication rate was twice as high after TT compared to HT. Total thyroidectomy requires life-long thyroid hormone supplementation, whereas such supplementation is required in only 30% of patients after HT. When surgery is indicated for Bethesda category II nodules, and in the absence of any indication for surgery on the contralateral lobe, HT is recommended. In patients with thyroid cancer (TC)≤1cm requiring surgical management or TC≤2cm, in the absence of risk factors for TC and in the absence of pre- or intraoperative detection of extrathyroidal extension, lymph node metastases (cN0) and/or suspected contra-lateral disease, HT is the preferred technique as long as the patient accepts the possibility of TT which might be required when aggressive forms of cancer are detected on definitive cytohistology (extrathyroidal extension, lymphovascular invasion, high-grade histology). For TC measuring between 2 and 4cm, the debate between HT and TT remains open today, although some surgeons tend to prefer TT. In patients with TC>4cm, macroscopic lymph node involvement (cN1), signs of extrathyroidal extension or predisposing factors for TC, TT is the treatment of choice.