A novel study for fluorescence patterns of the parathyroid glands during surgery using a fluorescence spectroscopy system

Purpose Recently it was reported that the parathyroid glands (PGs) emit autofluorescence when exposed to near infrared light, and a technique using fluorescence to detect the PGs intraoperatively was found to be useful. In some cases, however, it was difficult to detect the PGs. We sought to clarify the situation regarding such undetectable cases. Methods The study comprised 45 patients (50 sides) who underwent thyroid or parathyroid surgery at Kushiro city general hospital between November 2018 and June 2019. We searched for the PGs intraoperatively using a fluorescence spectroscopy system. We statistically considered the factors related to the fluorescence patterns of background in cases in which two PGs could not be confirmed using Fisher's exact test. Factors included age, gender, body-mass index, laterality, disease state, renal function, and comorbidity. Results In 41 sides (82%) fluorescence from at least one PG was determined. There was no significant difference in the detection rates among the other clinical factors. A "White out" pattern in which the background was too bright to detect PGs was observed in 11 sides (22%), and a "Black out" pattern in which the background and PGs were dark was observed in 18 sides (36%). Malignant disease was statistically associated with a "White out" pattern. No factors were found to be related to the "Black out" pattern. Conclusion In malignant disease, we should use this novel approach carefully.