Brent Griffith
Primary hyperparathyroidism, a disorder caused by the presence of one or more hyperfunctioning parathyroid glands, is ideally treated by surgical removal of the hyperfunctional tissue. In the past, this required bilateral cervical exploration, but improvements in preoperative gland localization and intraoperative parathyroid hormone assays have led to increased use of minimally invasive, or focused, parathyroidectomy techniques.1,2 These techniques can achieve the same outcomes while offering a lower risk profile for the patient.
The success of these minimally invasive techniques, however, is dependent on accurate preoperative localization of a potentially hyperfunctioning gland, which can sometimes prove challenging. While a number of imaging modalities are used for preoperative localization, multiphase CT has emerged in the last decade as a technique that not only offers the ability to detect parathyroid adenomas but also allows for precise anatomic localization. Since the initial description of multiphase CT by Rodgers et al3 in 2006 for localization of hyperfunctioning parathyroid glands, many studies have attempted to define the optimal number of phases needed for detection.
Our institution initially performed multiphase CT for parathyroid localization with 4 phases. However, due to concerns about radiation exposure, as well as our own clinical experience showing little added value to all 4 phases, the protocol was changed in 2009 to include only 2 phases, an arterial and venous phase.
The purpose of this study was to assess the accuracy of our 2-phase parathyroid CT for localizing surgically proven parathyroid adenomas in patients with primary hyperparathyroidism and to compare these accuracy rates with those of other techniques reported in the literature. Our study, which includes 278 patients, is the largest to date evaluating the accuracy of multiphase CT in the preoperative localization of pathologic parathyroid glands.