A dynamic nomogram model integrating serum phosphorus and longest diameter enhances diagnostic accuracy of 99mTc-MIBI imaging for parathyroid adenoma patients with elevated parathyroid hormone.

BACKGROUND: Parathyroid adenoma (PA) is the most common cause of primary hyperparathyroidism (PHPT). 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) imaging is widely applied in PA diagnosis and location. However, since the individual heterogeneity and adenoma function differences, the diagnostic efficacy of 99mTc-MIBI imaging is limited, which often leads to misdiagnosis and even mistreatment of PA.

METHODS: In the present study, we established a novel dynamic nomogram model to assist the nuclear imaging diagnosis of PA. A total of 96 PA patients, with 65 cases in the positive group and 31 cases in the negative group, were enrolled for further analyzing.

RESULTS: Univariate analysis showed there were no statistically significant differences between the two groups in terms of gender, age, and adenoma location. The patients in the positive group had significantly higher levels in PTH, serum calcium, longest diameter and shortest diameter of adenoma, compared to those in the negative group. But the serum phosphorus levels were lower in the positive group than in the negative group. Binary logistic regression analysis indicated that serum phosphorus and adenoma longest diameter were independent positive predictors. The dynamic nomogram model was generated by R software and logistic regression analysis (https://zhenglong-1988.shinyapps.io/dynnomapp/). The receiver operating characteristics curve (ROC curve) analysis revealed that the cut-off probability for the model to diagnose PA was 59.1%, with AUC values of 0.965.

CONCLUSIONS: The novel dynamic nomogram diagnostic model integrating serum phosphorus levels and longest diameter could effectively improve the diagnostic accuracy of radionuclide imaging for PA.