Background: The aim of this study was to evaluate the use of scintigraphy with thallium-201 chloride (201 Tl) and technetium-99m pertechnetate (99mTc) in the diagnosis of the localization of the pathological parathyroid glands in primary hyperparathyroidism and compare the results with those of high resolution ultrasonography.
Methods: Twelve patients of 56.1 +/- 7.8 years of age diagnosed with primary hyperparathyroidism were studied between March 1987 and June 1990. High resolution ultrasonography with a 7.5 MHz transducer and scintigraphy of digital subtraction with 201Tl-99mTc were carried out preoperatively in all the patients. None of the patients had had previous cervical surgery and diagnosis was proven following surgery by histopathologic study.
Results: Ultrasonography detected 9 out of 11 adenomas and 3 out of 4 hyperplastic glands. Scintigraphy identified 9 adenomas and only 2 of the hyperplastic glands. With this latter technique there was one false positive. The sensitivity of ultrasonography was 80% and that of scintigraphy was 73% with specificity being 100% vs 96.9%, respectively.
Conclusions: Subtraction 201 Tl-99mTc scintigraphy is useful in the diagnosis of the localization of pathologic parathyroid glands in patients with no previous cervical surgery although in this series this technique did not surpass that of high resolution ultrasonography.