Secondary hyperparathyroidism: detection with I-123-Tc-99m-Sestamibi subtraction scintigraphy versus US

To compare iodine-123-technetium-99m-sestamibi subtraction scintigraphy with ultrasonography (US) for detection of parathyroid abnormalities in uremic patients with secondary hyperparathyroidism.

Fourteen adult uremic patients with severe secondary hyperparathyroidism underwent subtraction scintigraphy before total or subtotal parathyroidectomy. Subtraction scintigrams were acquired with a double-energy-window technique. US was performed with high-frequency transducers and standard methods.

1-123-Tc-99m-sestamibi subtraction scintigraphy correctly demonstrated 41 of 50 surgically confirmed enlarged parathyroids; US demonstrated 27. Sensitivity for detection of hyperplastic glands was 82% for scintigraphy and 54% for US. Scintigrams were correct in seven patients, and US scans were correct in five. Scintigraphy demonstrated all four enlarged parathyroids in six of 12 patients who were to undergo first surgery, whereas US demonstrated all four enlarged glands in three of the 12 patients. Gland weight was correlated with likelihood of detection with either method. Glands undetected at scintigraphy were significantly (P < .01) smaller (mean weight, 257 mg) than those undetected at US (mean weight, 467 mg).

I-123-Tc-99m-sestamibi subtraction scintigraphy is efficient for detection of enlarged parathyroid glands in uremic patients with secondary hyperparathyroidism and is more sensitive than US.