Parathyroid imaging: how good is it and how should it be done?

Area of Science:

• Endocrinology
• Nuclear Medicine
• Surgical Oncology

Background:

• Primary hyperparathyroidism involves parathormone hypersecretion, commonly due to parathyroid adenoma (80-85%), hyperplasia (10-15%), or carcinoma (0.5-1%).
• Surgical excision is the primary treatment, with experienced surgeons achieving high success rates.

Purpose of the Study:

• To review the role of functional imaging in localizing parathyroid abnormalities for surgical planning.
• To compare the efficacy of different imaging modalities in primary hyperparathyroidism.

Main Methods:

• Review of literature on functional parathyroid imaging techniques.
• Analysis of sensitivity data for technetium-99m-sestamibi ([(99m)Tc]) scintigraphy in various parathyroid conditions.
• Discussion of complementary imaging like ultrasound and single-photon emission computed tomography (SPECT).

Main Results:

• Technetium-99m-sestamibi scintigraphy shows high sensitivity for solitary adenomas (88.44%) but lower sensitivity for multiglandular hyperplasia (44.46%) and double adenomas (29.95%).
• Subtraction imaging with [(99m)Tc]-sestamibi and iodine-123 ([(123)I]) is optimal for normal gland positions.
• Ultrasound and SPECT aid in equivocal cases and ectopic gland localization, respectively.

Conclusions:

• Functional imaging, particularly [(99m)Tc]-sestamibi with subtraction, is crucial for localizing parathyroid pathology, enhancing surgical outcomes.
• Experienced surgical and nuclear medicine teams are essential for optimal parathyroid service delivery.
• (11)C-methionine may be considered for persistent hyperparathyroidism with negative sestamibi imaging.