TcO/Tc-MIBI dual-tracer scintigraphy for preoperative localization of parathyroid adenomas

Abstract

Objective To investigate the accuracy of dual-tracer scintigraphy for locating parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). Methods We reviewed 268 patients with PHPT. All patients underwent technetium-99m pertechnetate ( 99m TcO 4 - ) scintigraphy and technetium-99m methoxyisobutylisonitrile ( 99m Tc-MIBI) dual-tracer scintigraphy of the thyroid and parathyroid glands, respectively. 99m TcO 4 - planar scintigraphy was carried out initially followed by dual-phase 99m Tc-MIBI single-photon emission computed tomography (SPECT)/CT the next day. The findings were combined and interpreted. Individual 99m Tc-MIBI and dual-tracer scintigraphy were both analyzed. The sensitivity, specificity, and accuracy were determined in relation to surgical findings. The average interval between scan and surgery was 13 days. Results The positive and negative predictive values of 99m Tc-MIBI SPECT/CT were 92.0% and 71.3%, respectively, and the sensitivity, specificity, and accuracy were 88.3%, 79.2%, and 85.8%, respectively. The positive and negative predictive values of dual-tracer scintigraphy were 96.3% and 82.3%, respectively, and the sensitivity, specificity, and accuracy were 92.9%, 90.3%, and 92.2%, respectively. Youden’s index for dual-tracer scintigraphy and 99m Tc-MIBI SPECT/CT were 0.83 and 0.63, respectively. Conclusions These finding suggest that 99m TcO 4 - and 99m Tc-MIBI dual-tracer scintigraphy is more accurate than other scintigraphy methods for detecting parathyroid adenoma, and may thus be the most suitable imaging technique in patients with PHPT.