Endocrine Abstracts

Introduction: Accurate preoperative localisation in primary hyperparathyroidism enables a localised approach to a parathyroidectomy operation. Ultrasonography is the most commonly used first-line imaging modality due to its widespread availability and safety. Parathyroid scintigraphy using MIBI is commonly used as the second-line imaging modality, as recommended by NICE. 4D-CT may have a role as a third-line imaging modality, when ultrasound and scintigraphy do not clearly localise a parathyroid adenoma. We audited our use of these preoperative imaging modalities in routine clinical care for parathyroid localisation in primary hyperparathyroidism.

Materials and Methods: We did a retrospective review of 36 patients who had parathyroid surgery in 2020-2021. We looked at the imaging results of these patients including parathyroid ultrasound, MIBI scan and 4D-CT and correlated the results with the operative and histopathological findings.

Results: Of 36 patients, 7 (19.4%) were males and 29 (80.6%) were females. Mean age was 63.6 years (Range: 41-84). Parathyroid ultrasound was done in all 36 patients and was successful in accurately localising a parathyroid adenoma in 19 patients (Sensitivity: 52.8%). MIBI scan was done in 25 patients and was successful in accurate localisation of a parathyroid adenoma in 17 patients (Sensitivity: 68%). 4D-CT was done in 11 patients with equivocal or unsuccessful imaging, after review and discussion at our parathyroid MDT. It was successful in correctly localising a parathyroid adenoma in 8 patients (Sensitivity: 72.7%).

Conclusion: If a parathyroid adenoma cannot be localised by ultrasonography and MIBI scan, 4D-CT could be considered. Accurate preoperative localisation makes it possible to perform a localised parathyroidectomy operation rather than full neck exploration, which is associated with advantages in terms of operating time. This helps reduce waiting times and could be factored into a cost-benefit analysis of pre-operative imaging protocols for primary hyperparathyroidism.