Prospective Validation of Two 4D-CT-Based Scoring Systems for Prediction of Multigland Disease in Primary Hyperparathyroidism

Background And Purpose: Patients with multigland primary hyperparathyroidism are at higher risk for missed lesions on imaging and failed parathyroidectomy. The purpose of this study was to prospectively validate the ability of previously derived predictive score systems, the composite multigland disease score, and the multiphase multidetector contrast-enhanced CT (4D-CT) composite multigland disease score, to identify patients with a high likelihood of multigland disease.

Materials And Methods: This was a prospective study of 71 patients with primary hyperparathyroidism who underwent 4D-CT and successful parathyroidectomy. The size and number of lesions identified on 4D-CT, serum calcium levels, and parathyroid hormone levels were collected. A composite multigland disease score was calculated from 4D-CT imaging findings and the Wisconsin Index (the product of the serum calcium and parathyroid hormone levels). A 4D-CT multigland disease score was obtained by using the CT data alone.

Results: Twenty-eight patients with multigland disease were compared with 43 patients with single-gland disease. Patients with multigland disease had a significantly smaller lesion size (P < .01) and a higher likelihood of having either ≥2 or 0 lesions identified on 4D-CT (P < .01). Composite multigland disease scores of ≥4, ≥5, and 6 had specificities of 72%, 86%, and 100% for multigland disease, respectively. 4D-CT multigland disease scores of ≥3 and 4 had specificities of 74% and 88%.

Conclusions: Predictive scoring systems based on 4D-CT data, with or without laboratory data, were able to identify a subgroup of patients with a high likelihood of multigland disease in a prospectively accrued population of patients with primary hyperparathyroidism. These scoring systems can aid in surgical planning.