The utility of 99mTc-sestamibi scintigraphy in the localisation of parathyroid adenomas in primary hyperparathyroidism.

Background: There are conflicting data in the literature about the sensitivity of sestamibi scintigraphy in parathyroid tumour localisation in primary hyperparathyroidism (PHPT).

Aim: We aimed to evaluate the overall sensitivity of this modality in parathyroid tumour localisation and to determine clinical and biochemical factors which influence sensitivity of this method.

Methods: We performed a retrospective review of 57 patients with a biochemical diagnosis of PHPT who had sestamibi scintigraphy performed.

Results: The sensitivity of sestamibi scanning was 56% in whole group and 63% in those without nodular thyroid disease. Among the patients with confirmed single gland disease (biochemical cure after surgical removal of a single adenoma), sensitivity was 71%. A positive scan was associated with younger age, greater adenoma weight and higher pre-operative serum calcium. Concordance between the sestamibi and neck ultrasonography was 92% accurate in pre-operative tumour localisation.

Conclusion: Sestamibi scintigraphy was more likely to be positive in younger patients without nodular thyroid disease who have larger parathyroid adenomas with more severe hyperparathyroidism.