Pre-operative imaging in primary hyperparathyroidism with ultrasonography and sestamibi scintigraphy

Resection of pathological parathyroid glands is the only curative therapy in primary hyperparathyroidism. Adequate pre-operative localization of the pathological glands is very useful, whichever surgical technique is preferred.

The aim of our study was to evaluate and compare high resolution ultrasonography and sestamibi scintigraphy as pre-operative imaging techniques and to explore their relationship with certain demographic and biochemical variables.

Data from 368 patients with primary hyperparathyroidism referred for surgery were retrospectively analysed. The results of pre-operative imaging were compared with the operative findings and the anatomopathological report.

In predicting the correct side of the lesion (right or left), ultrasonography had a positive predictive value (PPV) of 84%, whereas sestamibi imaging had a PPV of 93%. If both imaging techniques had a concordant positive result, the PPV was 99%. The PPV in predicting the correct quadrant, however, was only 61% for sestamibi scintigraphy and 40% for ultrasonography.

In our study, sestamibi imaging was better than ultrasonography as a single pre-operative localization imaging method for primary hyperparathyroidism. A concordant positive result was exceedingly reliable in indicating the side of the lesion. It seemed far more difficult to predict the quadrant correctly, especially because of misinterpretation of the upper adenomas.