Comparison of Sonography and Sestamibi Scintigraphy in the Localization of Parathyroid Adenoma in Primary Hyperparathyroidism

Introduction & Bilateral neck exploration is the good standard for parathyroid adenoma localization in primary hyperparathyroidism. But not all of surgeon have the necessary experience for accurate surgical exploration. But there are new methods for surgery like unilateral exploration and minimally invasive surgery. Thus, preoperative localization could reduce time and stress of surgery. In a prospective study 80 patients with documented primary hyperparathyroidism through raised serum calcium and parathyroid hormone (PTH), the results of sonographic localization were compared with the findings of surgery and 99mTechnetium sestamibi scintigraphy. Also variables such as preoperative serum calcium, PTH level and adenoma weight were compared between patients whom adenoma had been localized or not localized through sonography or Sestamibi scan with student’s t-test. In a prospective diagnostic tests accuracy study, 80 patients with primary hyperparathyroidism enrolled. Sonography detected enlarged parathyroid glands in 61 of 80 patients (76.3%), with sensitivity of 83.5% and positive predictive value (PPV) of 89.7%. Sestamibi scintigraphy detected adenoma in 63 patients (78.8%) with sensitivity of 85% and PPV of 91.3%. There was no significant deference between sonography and scintigraphy in localization of adenomas. When both sonography and scintigraphy were used for localization, they located 73 adenomas (91.3%), with sensitivity of 97.3% and PPV of 93.5%. Sonography is an accurate method for localization of enlarged parathyroid glands in primary hyperparathyroidism, and overall it is comparable with sestamibi scintigraphy. This study suggests a strategy of initial testing with one or the other method, followed by the alternate imaging test if the first test gives negative result.