Comparing intraoperative parathyroid identification based on surgeon experience versus near infrared autofluorescence detection - A surgeon-blinded multi-centric study

Abstract

Background: Near infrared autofluorescence (NIRAF) detection has previously demonstrated significant potential for real-time parathyroid gland identification. However, the performance of a NIRAF detection device - PTeye® - remains to be evaluated relative to a surgeon's own ability to identify parathyroid glands.

Methods: Patients eligible for thyroidectomy and/or parathyroidectomy were enrolled under 6 endocrine surgeons at 3 high-volume institutions. Participating surgeons were categorized based on years of experience. All surgeons were blinded to output of PTeye® when identifying tissues. The surgeon's performance for parathyroid discrimination was then compared with PTeye®. Histology served as gold standard for excised specimens, while expert surgeon's opinion was used to validate in-situ tissues.

Results: PTeye® achieved 92.7% accuracy across 167 patients recruited. Junior surgeons (<5 years of experience) were found to have lower confidence in parathyroid identification and higher tissue misclassification rate per specimen when compared to PTeye® and senior surgeons (>10 years of experience).

Conclusions: NIRAF detection with PTeye® can be a valuable intraoperative adjunct technology to aid in parathyroid identification for surgeons.

Keywords: Near infrared autofluorescence; Parathyroid glands; Parathyroidectomy; Surgical guidance; Thyroidectomy.

Conflict of interest statement

DISCLOSURES

A. Mahadevan-Jansen, J. E. Phay and Vanderbilt University have a licensing agreement with AiBiomed (Santa Barbara, CA) for PTeye®. A. Mahadevan-Jansen is also an equity holder at AiBiomed. Other authors have no conflicts of interest to declare.

Copyright © 2021 Elsevier Inc. All rights reserved.

Figures

Figure 1:

(A) Instrumentation of a fiber probe-based NIRAF detection modality – PTeye® – that consists of (1) the console that encloses the near infrared laser and the detector,(2) the display interface for guiding the surgeon, (3) a foot-pedal that is used by the surgeon to activate the laser for tissue NIRAF measurements, and (4) a detachable fiber-optic probe that illuminates the tissue and collects the resultant tissue NIRAF back to the detector in the console. (B) For each patient, a baseline NIRAF is established by taking 5 measurements on random sites on the thyroid gland. (C) NIRAF measurements are obtained by placing the fiber-optic probe on tissue of interest and pressing the pedal. NIRAF measurements with PTeye® are made with ambient operation room lights remaining on. The display monitor of PTeye® will then inform if the suspect tissue is parathyroid (D) or not (E)

Figure 2:

(A) A box and whisker plot representing the PTeye® Detection Ratios for parathyroid glands, thyroid glands and other soft tissues in the neck across all 3 study sites. Across all three study sites, the Detection Ratios was consistently elevated for parathyroid glands compared to the thyroid gland and other soft tissues in the neck. (B) A box and whisker plot representing the PTeye® Detection Ratio for healthy versus diseased parathyroid glands across all 3 study sites. While there is no significant difference in Detection Ratios for healthy versus diseased glands at Site 1 and 2, diseased glands had significantly lower detection ratio than healthy glands at site 3. ** - statistically significant difference where p-value ≤ 0.5

Figure 3:

(A) Distribution of a surgeon’s confidence level in identifying parathyroid glands across all 3 study sites. t = number of times a potential parathyroid candidate was seen by the surgeon. (B) Distribution of tissue misclassification rates of surgeons across all 3 study sites, when excised specimens were validated with histology. n = number of tissues validated with histology for each surgeon. The overall findings imply that the lesser experienced surgeons are likely to have lower confidence and accuracy in identifying parathyroid glands. Please note that the surgeon’s skill in identifying parathyroid glands was solely based on their surgical experience, as all surgeons were blinded to the output of PTeye® in this study. * - only 2 specimens were validated histologically for Surgeon D.