Determination of Parathyroid Function by Fluorescence With Indocyanine Green (ICG) After Total Thyroidectomy

The main objective of the study is to compare the intensity of parathyroid fluorescence among patients who present post-thyroidectomy hypocalcemia with that of patients who do not have it. Therefore, the following points will be studied: * To study the correlation between parathyroid vascularization (intraoperative fluorescence intensity) and postoperative glandular function (serum calcium and parathormone levels). * To compare the surgeon's subjective assessment of parathyroid fluorescence in the groups of patients with and without postoperative hypocalcemia. * To compare the objective assessment of parathyroid fluorescence, by using specific computer software developed ad hoc, in the groups of patients with and without postoperative hypocalcemia.