Parathyroid scintigraphy during hypocalcaemia in primary hyperparathyroidism.

Area of Science:

• Nuclear Medicine
• Endocrinology
• Surgical Imaging

Background:

• Minimally invasive parathyroid surgery for primary hyperparathyroidism (PHPT) requires high imaging accuracy.
• Current scintigraphy methods can be improved by enhancing parathyroid adenoma visualization.

Purpose of the Study:

• To introduce and evaluate a novel technique, stimulated parathyroid scintigraphy (SPS), for improved parathyroid adenoma localization.
• To assess if increasing blood flow to the parathyroid adenoma enhances scintigraphic detection.

Main Methods:

• SPS involves injecting (99m)Tc-pertechnetate, performing a thyroid scintigram, infusing sodium citrate to lower calcium and increase blood flow, injecting (99m)Tc-sestamibi, and obtaining neck scintigrams.
• A subtraction technique was used, comparing thyroid and sestamibi scintigrams, with a delayed scan after perchlorate administration.
• Ultrasound and Doppler were used in nine patients to assess flow changes and adenoma localization.

Main Results:

• Stimulated parathyroid scintigraphy (SPS) correctly localized 88% of parathyroid adenomas.
• Conventional (99m)Tc-sestamibi scintigraphy achieved 62% accuracy.
• Citrate infusion demonstrably increased tissue perfusion in the studied adenomas.

Conclusions:

• SPS is a highly accurate and easily performed technique for parathyroid adenoma localization.
• The subtraction-based SPS procedure can be completed within one hour, making it suitable for same-day surgery.
• SPS offers a significant improvement in imaging accuracy for patients undergoing parathyroid surgery.