Z. Song1, R. Wang1, C. Harper1, P. V. Zmijewski1, C. McLeod1, A. Gillis1, B. Lindeman1, H. Chen1, J. Fazendin1 1University Of Alabama at Birmingham, Surgery, Birmingham, Alabama, USA
Introduction: Several adjuncts have been utilized intraoperatively to guide successful parathyroidectomy(PTx), however, with a long wait time, taking 30-60 minutes to result. Hyperfunctioning parathyroid glands have been shown to have increased mitochondrial metabolic activity. We sought to determine if the intraoperative measurement of parathyroid mitochondrial metabolic activity(MMA) could be utilized to predict parathyroid pathology and guide surgical decision-making time-efficiently.
Methods: We retrospectively reviewed patients with primary hyperparathyroidism(HPT) who underwent PTx at our institution(2000-2022). All patients received a preoperative injection of 10mCi of 99Tc. Intraoperatively, radioactivity was measured by a gamma counter within 5 seconds. The MMA was calculated as the ratio of the radioactivity count of resected parathyroid glands to background thyroid tissue. Patient demographics, preoperative laboratory measurements, MMAs, and wait times for results were compared between patients with single-gland disease(SGD) versus multi-gland disease(MGD). The predictive threshold for SGD was subsequently validated on the following cohort of 34 patients.
Results: Of 2368 patients included, 1,585(66.9%) patients had SGDs, and 783(33.1%) had MGDs. Ninety-nine percent of patients had MMA above 0.2. There were Patients with SGD had a higher median(IQR) MMA than the MGD group [0.8(0.5 – 1.3) vs. 0.4(0.3-0.7), p<0.001]. After adjusting for age, preoperative calcium and PTH, reoperative PTx, and gland weight, the MMA ratio was an independent predictor(OR 2.155, 95% CI 1.791-2.593, p<0.001) of SGD. A ROC curve was plotted using the MMA ratio to predict the likelihood of SGD. The positive predictive value(PPV) of MMA to predict SGD reached a plateau at 85.3% when the ratio was 1.2(Figure 1). When examined using the ratio of 1.2 as the threshold in the validation cohort, the PPV was 100%.
Conclusion: MMA provides an instantaneous and reliable prediction of parathyroid pathology. This simple intraoperative measurement could be used as an adjunct to guide surgical decision-making during PTx in a much more time-efficient manner.
