Purpose: Ultrasound (US) and scintigraphy are used most frequently of all the available imaging techniques for the preoperative evaluation of patients with possible primary hyperparathyroid disease. The aim of this study was to assess the value of dual-phase Tc-99m MIBI scintigraphy compared with US in the detection of adenomatous or hyperplastic glands and in the surgical decision-making process for patients with a biochemical diagnosis of primary hyperparathyroid disease.
Methods: Ninety-seven patients with increased levels of parathyroid hormone and calcium, and at least 6 months' follow-up after US and scintigraphy, were examined retrospectively to assess the influence of the diagnostic work-up on the therapeutic decision of the referring clinicians and to evaluate the sensitivity of these diagnostic tools in the surgically treated patients. Forty-eight patients underwent surgery.
Results: Parathyroid adenomas were found in 43 patients and hyperplasia in 1, whereas 4 patients had no evidence at surgery. The sensitivity and specificity rates were 84.4% and 95.9% for scintigraphy, and 66.6% and 98.6% for US, respectively. Of the 49 nonsurgically treated patients, 35 had negative results with both MIBI and US; only 3 had positive findings with both imaging methods. Patients treated conservatively had significantly lower parathyroid hormone and serum calcium levels than did the patients who had surgery.
Conclusions: The data suggest that the high sensitivity of dual-phase MIBI scintigraphy can improve the detection of hyperfunctioning parathyroid glands. Furthermore, despite the controversy surrounding the use of imaging methods in the preoperative assessment of primary hyperparathyroid disease, these data suggest that the decision of the clinician to order surgery for a patient with a moderate increase of serum PTH level may be influenced by the results of the imaging methods.