Pathological evaluation of the accuracy of a fluorescence spectroscopy system for detecting parathyroid glands

A fluorescence-based technique for the detection of parathyroid glands (PGs) intraoperatively was previously reported. The technique was based on the phenomenon in which PGs emit autofluorescence when exposed to near-infrared light and we undertook an evaluation to consider the pathological accuracy of the method.

The study comprised 17 patients (18 specimens) who underwent thyroid surgery at Kushiro City General Hospital between November 2018 and June 2019. We searched for PGs intraoperatively using a fluorescence spectroscopy system and evaluated the pathological accuracy of the system. We statistically evaluated the clinical factors associated with the accuracy of the system, including age, gender, body mass index, laterality, disease state, renal function, and comorbidity.

Eighteen specimens were evaluated pathologically, with 13 specimens confirmed as PGs. These were evaluated as "true positive," giving a positive predictive value of 72.2% (13/18). Among the false-negative cases, one specimen was a metastatic lymph node in a patient with papillary thyroid carcinoma. There was a significant difference in the true-positive rates between malignant (25%) and benign (85.7%) disease (P = 0.044).

We consider that this technique is useful, however, we have to exercise care in malignant cases as the true-positive rate may be low.