Introduction: Most pathologic parathyroid glands will localize with neck ultrasound and/or Tc99m-sestamibi; however, a subset of patients will have non-localizing disease despite adequate initial imaging.1 These patients require either bilateral neck exploration (BNE) or advanced imaging in hopes of identifying pathologic gland(s) and proceeding with unilateral neck exploration (UNE). Our institution has previously shown that outcomes from BNE without further imaging are comparable to those seen in surgery for localized disease; however, the cost-effectiveness of a BNE-first strategy compared to further imaging has not been evaluated.
Methods: A decision tree model was developed for the scenario of a patient with confirmed primary hyperparathyroidism and previously negative ultrasound and sestamibi scan. Financial data was extracted from the 2018 Center for Medicare Services (CMS) Fee Schedule, 2018 OSHPD Chargemaster document for Loma Linda University Medical Center (LLUMC), and internal reports of CMS allowed charges for procedure 60500 from the LLUMC billing department. Financial calculations were completed from the perspective of the insurance provider (CMS) based on allowed charges for the pertinent CPT codes. Operative outcomes were extracted from previously published institutional data.2 Radiological data was drawn from recent meta-analyses of imaging in primary hyperparathyroidism.3,4 One-way sensitivity analysis was conducted to model the effects of changes in cost or outcome variables.
Results: Based on institutional-specific outcomes, BNE cost $9475 and had a success rate of 97.3%. SPECT had a total cost of $8667 with a success rate of 98.8%. SPECT/CT was modelled to have a total cost of $8634 and a 98.9% success rate. 4D-CT was projected to cost $8393 with a success rate of 99%. Incremental cost-effectiveness ratios (as compared to BNE) were -538.9, -525.9, and -636.8 ($/percent cure rate) for SPECT, SPECT/CT, and 4D-CT respectively. One-way sensitivity analyses (Figure 2) demonstrate the change in IECR and cut-off points (IECR=0) for four major variables.
Conclusion: In patients with non-localizing primary hyperparathyroidism, advanced imaging is associated with cost-savings compared to routine bilateral neck exploration. Increased cost-savings were predicted with increased imaging accuracy and decreased imaging costs. Increasing time for BNE or decreasing time for UNE were associated with increased cost savings. Limitations to this study include lack of radiologic accuracy data specific to the subpopulation of patients with non-localizing hyperparathyroidism and institutional variances in associated charges and clinical outcomes.
1. Payne et al. Am J Otolaryngol. 2015;36(2):217-222.
2. Vuong et al. Head Neck. (In Press).
3. Cheung et al. Ann Surg Oncol. 2012;19:577-583.
4. Bunch et al. JAMA Otolaryngol Head Neck Surg. 2018;144(10):929-937.
Figure 1: Decision Tree
Figure 2: One-way Sensitivtiy Analysis Graphs for Cost and Accuracy of Radiologic Studies
Figure 3: One-way sensitivity Analysis Graphs for Operative Time