Preoperative localization of parathyroid adenomas: ultrasonography, sestamibi scintigraphy, or both?

Minimal access techniques are increasingly used to remove parathyroid adenomas. Such surgery depends on accurate preoperative localization but the selection of imaging modality remains controversial. We have reviewed the accuracy of ultrasonography, sestamibi scintigraphy and their combination in 48 cases of primary hyperparathyroidism. Ultrasound had a sensitivity of 64.3% (95% confidence interval 44.1-81.4) and positive predictive value (PPV) of 100% (81.5-100) for correct lateralization. Sestamibi had a sensitivity of 83.3% (69.8-92.5) and PPV of 87.1% (73.7-95.1). The simple combination of ultrasound with sestamibi had a sensitivity of 82.1% (63.1-93.9) and a PPV of 92.0% (74.0-99.0): little different from sestamibi alone. However, if the sestamibi result was disregarded in favour of ultrasonography in discordant cases, the sensitivity reached 96.4% (81.7-99.9) and the PPV was 100% (87.2-100). These results were not dependant on a learning curve or the size of adenoma.