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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
80
ICG-NIRF was performed using the Quest Spectrum Platform 2.0. The camera lens was positioned at a fixed distance of 30 cm to the wound bed, at a perpendicular angle, with the gain set at 22.5 decibels (dB) and an exposure time of 50 milliseconds (ms). ICG was dissolved in sterile water at a concentration of 2.5 mg/mL as recommended by the manufacturer (Verdye). 1.5 mg of ICG per liter of circulating blood volume was then administered through manual bolus intravenous injection. Blood volume estimation was based on the patient\'s height and weight.
ICG-NIRF was performed using the Quest Spectrum Platform 2.0. The camera lens was positioned at a fixed distance of 30 cm to the wound bed, at a perpendicular angle, with the gain set at 22.5 decibels (dB) and an exposure time of 50 milliseconds (ms). ICG was dissolved in sterile water at a concentration of 0.5 or 2.5 mg/mL as recommended by the manufacturer. 1.5 mg of ICG per liter of circulating blood volume was then administered through manual bolus intravenous injection. Blood volume estimation was based on the patients height and weight. Different administration rates (fast: 2s, slow: 15-20s) and a different camera system were tested. Group 1: Quest Platform 2.0; Fast/Slow; 2.5 mg/mL Group 2: Quest Platform 2.0; Slow/Fast; 2.5 mg/mL Group 3: Quest Platform 2.0; Fast/Fast; 2.5 mg/mL Group 4: Stryker Spy-Elite; Fast/Fast; 2.5 mg/mL Group 5: Quest Platform 2.0; Fast/Fast; 0.5 mg/mL
University Medical Center Groningen
Groningen, Netherlands
Erasmus Medical Center Rotterdam
Rotterdam, Netherlands
Injection speed
The impact of injection speed on a parathyroid perfusion curve (slow vs fast)
Time frame: During surgery
ICG concentration
The impact of ICG concentration on a parathyroid perfusion curve (2.5 mg/mL vs 0.5 mg/mL)
Time frame: During surgery
Camera system
The impact of a camera system on a parathyroid perfusion curve (Quest vs SpyElite)
Time frame: During surgery
Multicenter application
The correlation between postoperative hypoparathyroidism and the perfusion curve in two different centers (UMCG/EMC)
Time frame: From surgery until one day post-surgery
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