*2.1. Search Strategy*

This systematic literature review was conducted according to the Preferred Reporting in Systematic Review and Meta-Analysis (PRISMA) guidelines [40]. MEDLINE (PubMed), Science Direct, Google Scholar, Medline, Oxford Academic journals, and Cochrane library databases were searched, with MeSH terms and free-text key words used for studies investigating the role of fluorescence-guided surgery in preventing hypoparathyroidism as a complication of thyroidectomy for thyroid cancer. The following search string was then developed: (Fluorescence-guided surgery OR Fluorescence imaging OR Indocyanine green OR Near-infrared imaging OR Autofluorescence) AND (Thyroid cancer OR Thyroid malignancy) AND Thyroidectomy AND (Parathyroid glands OR Hypoparathyroidism). To complete the search, the references within the selected articles were searched as well. The search was conducted until May 2021 by the authors. No age or time limitations were

used. After the titles and abstracts had been screened, full-text reports were assessed for eligibility, and references were screened within the selected articles.

A standard form for extracting the following data was used, addressing the characteristics of the selected studies (design, method of randomization), participants (baseline characteristics, tumor type, indication for surgery), and intervention (type of surgery, operative technique, lymph node dissection, type of fluorescence, type of fluorescent dye, dose, timing of administration during surgery, fluorescence system). Outcomes were influence on procedure duration, intra- and postoperative complications, and, particularly, presence of temporary and/or permanent hypoparathyroidism. These data were analyzed and are reported in tables and text. Outcome variables are reported as the absolute number and percentage, for all studies combined and separately for those studies with a control group.
