Pre-operative sestamibi-technetium subtraction scintigraphy in primary hyperparathyroidism: experience with 156 consecutive patients.

AIM: The aim of this study was to assess the usefulness of pre-operative sestamibi-technetium subtraction scintigraphy in a large cohort of patients with primary hyperparathyroidism (HPT).

MATERIALS AND METHODS: A group of 156 consecutive patients with biochemically proven HPT underwent sestamibi-technetium subtraction scintigraphy before cervical exploration. Images were interpreted and reported prospectively and influenced the extent of surgical exploration. The intraoperative findings were compared retrospectively with the pre-operative scintigram reports in 154 individuals with technically satisfactory scintigrams.

RESULTS: Of the 154 patients with satisfactory scintigrams, 122 (78.2%) demonstrated a single focus of activity following subtraction, 31 (19.9%) had negative findings and the remaining scintigram showed four foci of activity. At operation 138 (89.6%) solitary adenomas were removed, 13 patients (8.4%) had multi-gland disease and in three individuals (2.0%) no abnormal parathyroid tissue was found. The pre-operative scintigram accurately localized 91 of 98 (92.9%) solitary tumours weighing > 500 mg but only 18 of 35 (51.4%) adenomas weighing < 500 mg, (P < 0.0001). Overall sensitivity of sestamibi-technetium scintigraphy for localizing single parathyroid adenomas was 83.7%.

CONCLUSION: Sestamibi-technetium subtraction scintigraphy will accurately localize a high proportion of solitary parathyroid adenomas but its usefulness is diminished by its inability to consistently identify smaller tumours.