Four-dimensional computed tomography and ultrasonography for prediction of pathological parathyroid location: a retrospective review of a single surgeon's patients at a single institution

Background: Pre-operative imaging is a well-established practice for managing hyperparathyroidism with the plan for excision; however, there is a paucity of information regarding the success rate of concordant imaging studies. Our goal was to compare the accuracy (sensitivity) of four-dimensional computed tomography (4DCT) and ultrasound (US) when predicting the side and quadrant of parathyroid lesions, confirmed with surgical location (from a single surgeon).

Methods: A retrospective review of 437 patients from a single surgeon undergoing parathyroidectomy from December 2013 to January 2020 at an academic medical center was performed. Masses >5 mm in dimension in eutopic parathyroid locations were identified as possible parathyroid lesions on 4DCT. A unique codified system was utilized to accurately record imaging results for each modality and compared to surgical findings.

Results: Four hundred and thirty-seven patients underwent parathyroid surgery, of those 431 underwent 4DCT, 413 underwent US, and 408 underwent both. 4DCT accurately lateralized lesions in 319 (74.0%; N=431). US lateralized lesions in 265 (64.2%; N=413). The sensitivity for lateralization was 81.2% and 69.9% for 4DCT and US, respectively.

Conclusions: 4DCT and US identify the majority of parathyroid lesions. 4DCT outperformed US in lateralization yet both modalities remain useful and are complimentary in planning for successful parathyroidectomy. Newer imaging approaches such as ¹⁸F-choline positron emission tomography/computed tomography (PET/CT) and artificial intelligence as an augmentation to imaging review may play in role to identify parathyroid adenomas/hyperplasia, but their roles have yet to be clearly defined.