The Usefulness of 99mtechnetium-sestamibi Parathyroid Scintigraphy in Preoperative Localization of Parathyroid Adenoma in Patients with Primary Hyperparathyroidism at an Academic Hospital in South Africa

Background: Primary hyperparathyroidism (PHPT) is an endocrine disorder with increased secretion of parathyroid hormone and elevated serum calcium level. Parathyroid adenoma is the most common cause. The introduction of preoperative localization of parathyroid adenoma using 99mTc-sestaMIBI has made parathyroid surgery minimally invasive. It becomes important to determine its usefulness in actual localization of parathyroid adenoma by correlating such with surgical and histological outcomes.

Methods: This is a retrospective evaluation which involved electronic data retrieval for patients with biochemical diagnosis of hyperparathyroidism who presented for parathyroid nuclear scan and subsequently had surgical resection and histopathological diagnosis at the UAH. A total of 11 patients were involved in this study. Data obtained was analysed.

Results: The mean age of the study group was a 55.82±15.46 year (age range of 29 years to 81 years) and females constituted 81.8% of the study group. The mean corrected calcium level was high preoperatively (2.93±0.5) but normalized post-operatively (2.29±0.3) (p <0.001) while preoperative mean parathyroid hormone level was also high (26.86 ±44.5) but normalized post-operatively (5.66± 2.2) (p <0.001). All the 11 patients had positive 99mTc-Sestamibi scan for parathyroid adenoma and 27.3% of these patients had multiple (two) parathyroid adenomas. A total of 14 parathyroid adenomas were therefore detected. The surgeons detected and excised parathyroid adenomas at locations depicted by the 99mTc-sestamibi scan for all the eleven patients and 14 sites. All of the fourteen excised tissue were subsequently confirmed by histology to be parathyroid adenoma.

Conclusion: Findings of this study showed accurate localization of parathyroid adenoma in all the patients as confirmed by surgery, histology and normalized post-operative corrected calcium and parathyroid hormone. Hence dual-phased 99mTc-sestamibi scintigraphy in the preoperative localization of parathyroid adenoma in patients with primary hyperparathyroidism at the Universitas Academic Hospital, Bloemfontein is a useful procedure.