Three‐phase four‐dimensional computed tomography as a first‐line investigation in primary hyperparathyroidism

Abstract

Introduction: Parathyroid computed tomography using multiple phases (four-dimensional computed tomography (4DCT) for parathyroid localization was first described in 2006. Since its inception, there has been variable uptake of this technique due to inconsistency of results between institutions and perceived higher radiation dose than technetium-99 sestamibi scans (MIBI). 4DCT has been the primary imaging modality for parathyroid localization at our institution since 2013. Methods: A retrospective study of surgically managed patients with primary hyperparathyroidism who had preoperative localization with 4DCT from 2013-2018 was performed. Results: A total of 353 patients were included for analysis. The positive predictive value (PPV) of our three-phase 4DCT protocol was 93.3%, sensitivity (localized) 85.2% with a 5.8% false-positive rate and 13.9% false-negative (non-localizing) rate when reported by a head and neck radiologist (HNR). Calculated effective dose varied from 4.5 to 8.9mSV. On multivariable logistic regression, reporting by an experienced HNR (P < 0.001) and gland weight > 200 mg (P = 0.002) were significant for higher accuracy, lower false positives and false negatives. Conclusion: A first-line three-phase 4DCT protocol for primary hyperparathyroidism is an accurate technique providing precise anatomical localization of abnormal parathyroid glands, particularly when performed by a specialist HNR. In our practise, it provides the best rate of detection and superior anatomical localization needed for minimally invasive parathyroid surgery, compared to other commonly used localization techniques. It also avoids the need for four gland exploration in the majority of patients with primary hyperparathyroidism.

Lessons learnt from the global iodinated contrast media shortage in head and neck imaging

“…It should also be noted that bilateral neck exploration remains the gold standard for curative treatment with similar success rates to MIP, and may be considered where preoperative parathyroid localisation is unavailable or equivocal. 24,26,[38][39][40]…”

“…Local results demonstrate an 85% sensitivity and 93% positive predictive value for 4D-CT when reported by an experienced head and neck radiologist, superior to the accuracy of US and sestamibi imaging in both local audits and the wider literature. 38 For patients unable to receive ICM, our institution utilises the combination of non-contrast-enhanced CT (NECT) with US performed by a head and neck radiologist as a viable alternative. It should also be noted that bilateral neck exploration remains the gold standard for curative treatment with similar success rates to MIP, and may be considered where preoperative parathyroid localisation is unavailable or equivocal.…”

“…4D‐CT has been used as the primary imaging modality for parathyroid localisation at our institution for several years, in part due to the operator dependence of US and the availability of local expertise. Local results demonstrate an 85% sensitivity and 93% positive predictive value for 4D‐CT when reported by an experienced head and neck radiologist, superior to the accuracy of US and sestamibi imaging in both local audits and the wider literature 38 . For patients unable to receive ICM, our institution utilises the combination of non‐contrast‐enhanced CT (NECT) with US performed by a head and neck radiologist as a viable alternative.…”

“…For patients unable to receive ICM, our institution utilises the combination of non‐contrast‐enhanced CT (NECT) with US performed by a head and neck radiologist as a viable alternative. It should also be noted that bilateral neck exploration remains the gold standard for curative treatment with similar success rates to MIP, and may be considered where preoperative parathyroid localisation is unavailable or equivocal 24,26,38–40 …”

Four-dimensional computed tomography as first-line imaging in primary hyperparathyroidism, a retrospective comparison to conventional imaging in a predominantly single adenoma population

“…Depending on local experience and availability, this may be a four-dimensional computed tomography (4DCT) or [ 18 F]fluorocholine PET/CT (FCH) with sensitivities ranging between 75 and 97% for 4DCT and 85-97% for PET/CT (Bahl et al 2014 ; Bunch et al 2022 ; Ballester Vazquez et al 2020 ; Broos et al 2019a , b ). Few articles describe the role of 4DCT as first-line imaging technique (Jong et al 2021 ; Leong et al 2021 ). The present paper compares 4DCT as first-line imaging to the conventional combination of US and MIBI.…”