Diagnostic Accuracy Study of Indocyanine Green for Perfusion Assessment

Background Near-infrared fluorescence guided surgery with indocyanine green (ICG) was introduced for parathyroid perfusion assessment during total thyroidectomy in 2016. ICG can visualize tissue perfusion, since it becomes completely and permanently fixed to plasma proteins in the bloodstream, and circulates in the intravascular compartment only. ICG was already approved in 1956 for clinical use of tissue perfusion. However, until now there is still no (parathyroid) universal standard imaging protocol for ICG-guided fluorescent surgery including quantitative evaluation. Main research question To develop a standardized universal imaging protocol for the assessment of parathyroid perfusion during total thyroidectomy with ICG including quantitative evaluation of the fluorescent signal. • Design (including population, confounders/outcomes) This will be a proof-of-concept, prospective cohort study of patients undergoing an ICG-guided fluorescent total thyroidectomy to evaluate parathyroid gland perfusion. The main study endpoint is quantification of the fluorescent signal of ICG stratified by the occurrence of hypoparathyroidism. Hypoparathyroidism will be defined as a decrease in PTH of \>70% at the first postoperative day. Furthermore, we will calculate the sensitivity of our model for the prediction of hypoparathyroidism. Secondary outcomes are data from surgery, pre- and postoperative lab values (including calcium, PTH, albumin) and postoperative medication use. Expected results We expect that the results of this study will lead to the development of a universal standard imaging protocol for ICG-guided fluorescent total thyroidectomy.