The impact of combined interpretation of localization studies on image-guided surgical approaches for primary hyperparathyroidism.

Background: The impact of single and combined interpretations of ultrasonography and sestamibi scintigraphy to select the appropriate surgical approach in patients with primary hyperparathyroidism were evaluated retrospectively.

Methods: A total of 183 patients with primary hyperparathyroidism who were evaluated preoperatively using both ultrasonography and sestamibi scintigraphy were included in the study. The results of preoperative localization studies were correlated with intraoperative findings and postoperative histopathological results. The localization rates of individual and combined interpretations of ultrasonography and sestamibi scintigraphy were evaluated.

Results: The overall sensitivity and the positive predictive value of ultrasonography and sestamibi scintigraphy were 76% and 90%, and 81% and 91%, respectively. Both imaging studies were concordant for the same localization(s) in 121 (66%) of 183 patients. The prevalence rates of single-gland and multiglandular disease were 90% (N.=109) and 10% (N.=12), respectively, in patients with concordant results (P=0.0001). The overall rate of localization was 91% (N.=110) in these patients. In these patients with concordant results, the sensitivity and the positive predictive value of imaging were 91% and 100%, respectively. The localization rates were 96% and 42% for single-gland and multiglandular disease, respectively (P=0.0001). Of the remaining 62 patients, 50 had negative imaging with either ultrasonography (N.=29) or MIBI (N.=21). Of the 29 patients with negative ultrasonography results, sestamibi scintigraphy was positive in 23. Of the 21 patients with negative sestamibi scintigraphy imaging, ultrasonography was positive in 15. Thus, 38 patients had a single positive imaging result. The majority (95%) of these 38 patients had single-gland disease, and the rate of multiglandular disease was 5% (P=0.0001). The rate of localization was 95% (36/38) in patients with a single positive imaging study. Eighteen patients had discordant imaging results.

Conclusions: The overall rate of localization in primary hyperparathyroidism is greater than 90% if ultrasonography and sestamibi scintigraphy are concordantly positive for the same localization, and the prevalence of multiglandular disease is low in patients with concordant imaging. An image-guided surgical approach and selective parathyroidectomy exhibit high cure rates in the setting of concordantly positive sestamibi and ultrasonography results, even if intraoperative parathormone monitoring is not used.