Original Investigation 

August 2, 2023

Intraoperative Identification of Thyroid and Parathyroid Tissues During Human Endocrine Surgery Using the MasSpec Pen

Rachel J. DeHoog, Mary E. King, Michael F. Keating, et al

JAMA Surg. Published online August 2, 2023. doi:10.1001/jamasurg.2023.3229

Key Points

Question  Does the metabolic information provided by the MasSpec Pen (MSPen) technology enable intraoperative discrimination of parathyroid, thyroid, and lymph node tissues in vivo for tissue identification?

Findings  In this diagnostic/prognostic study, molecular profiles of metabolites were obtained from MSPen analysis of thyroid, parathyroid, and lymph node tissues in the laboratory and intraoperatively and used to build statistical classifiers to discriminate cervical endocrine tissues. Prediction on an independent data set of intraoperative in vivo and freshly excised tissues yielded excellent agreement with pathology.

Meaning  The findings suggest that MSPen technology may enable intraoperative identification of tissues during thyroid and parathyroid surgical procedures.

Abstract

Importance  Intraoperative identification of tissues through gross inspection during thyroid and parathyroid surgery is challenging yet essential for preserving healthy tissue and improving outcomes for patients.

Objective  To evaluate the performance and clinical applicability of the MasSpec Pen (MSPen) technology for discriminating thyroid, parathyroid, and lymph node tissues intraoperatively.

Design, Setting, and Participants  In this diagnostic/prognostic study, the MSPen was used to analyze 184 fresh-frozen thyroid, parathyroid, and lymph node tissues in the laboratory and translated to the operating room to enable in vivo and ex vivo tissue analysis by endocrine surgeons in 102 patients undergoing thyroidectomy and parathyroidectomy procedures. This diagnostic study was conducted between August 2017 and March 2020. Fresh-frozen tissues were analyzed in a laboratory. Clinical analyses occurred in an operating room at an academic medical center. Of the analyses performed on 184 fresh-frozen tissues, 131 were included based on sufficient signal and postanalysis pathologic diagnosis. From clinical tests, 102 patients undergoing surgery were included. A total of 1015 intraoperative analyses were performed, with 269 analyses subject to statistical classification. Statistical classifiers for discriminating thyroid, parathyroid, and lymph node tissues were generated using training sets comprising both laboratory and intraoperative data and evaluated on an independent test set of intraoperative data. Data were analyzed from July to December 2022.

Main Outcomes and Measures  Accuracy for each tissue type was measured for classification models discriminating thyroid, parathyroid, and lymph node tissues using MSPen data compared to gross analysis and final pathology results.

Results  Of the 102 patients in the intraoperative study, 80 were female (78%) and the median (IQR) age was 52 (42-6) years. For discriminating thyroid and parathyroid tissues, an overall accuracy, defined as agreement with pathology, of 92.4% (95% CI, 87.7-95.4) was achieved using MSPen data, with 82.6% (95% CI, 76.5-87.4) accuracy achieved for the independent test set. For distinguishing thyroid from lymph node and parathyroid from lymph node, overall training set accuracies of 97.5% (95% CI, 92.8-99.1) and 96.1% (95% CI, 91.2-98.3), respectively, were achieved.

Conclusions and Relevance  In this study, the MSPen showed high performance for discriminating thyroid, parathyroid, and lymph node tissues intraoperatively, suggesting this technology may be useful for providing near real-time feedback on tissue type to aid in surgical decision-making.