[4-dimensional computed tomography for localization of parathyroid adenoma]

In about 85% of patients with primary hyperparathyroidism (pHPT) only a single parathyroid gland is diseased. The operation of choice in this group of patients is minimally invasive parathyroidectomy (MIP). In order to perform an MIP, the diseased gland should be identified prior to surgery. This is not always possible with the routine imaging studies including parathyroid sestamibi scan and ultrasound. Four-dimensional computed tomography (4D-CT) scanning was developed in order to identify an enlarged parathyroid gland. Several characteristics make it possible to identify glands of this type and to differentiate it from other neck nodes.

To evaLuate the accuracy of 4D-CT in the identification of parathyroid adenoma/s in order to perform an MIP.

A total of 69 patients underwent parathyroidectomy for pHPT during the period July 2010 to June 2012. The 4D-CT was performed on 27 patients. Data were retrospectively extracted from the patients' charts including imaging studies, operative notes, number and LocaLization of glands excised and pathological reports.

The 4D-CT was positive for a single adenoma in 26 patients confirmed in surgery. In 4 of those patients, one or two additional glands were found enlarged during surgery. Sixteen patients underwent an MIP, 3 patients had a unilateraL exploration and in 8 cases a biLateraL exploration was performed. The 4D-CT had a sensitivity of 81.4% and a positive predictive value of 100% in this group of patients.

The 4D-CT is another tool for the identification of enlarged parathyroid gLand/s before surgery. Further study is needed to determine its place in the current armamentarium of pre-operative localization studies.