Parathyroid adenoma Localization.

BACKGROUND: Bilateral neck exploration is the gold standard for parathyroid adenoma localization in primary hyperparathyroidism. But surgeons do not have adequate experience for accurate surgical exploration and new methods are developed for surgery like unilateral exploration and minimally invasive surgery, thus, preoperative localization could reduces time and stress in surgical performance.

METHOD: 80 patients with documented primary hyperparathyroidism and with raised serum calcium and parathyroid hormone (PTH) were selected. The results of ultrasonographic localization for each patient were compared with findings of surgery and 99m technetium sestamibi scintigraphy. Also variables such as preoperative serum calcium, PTH level and adenoma weight were compared between patients who had localized and non-localized adenoma with ultrasonography or Sestamibi scan. The data was compared with student's t-test.

RESULTS: In a prospective diagnostic tests accuracy study, 80 patients with primary hyperparathyroidism were enrolled. Ultrasonography images 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 ultrasonography and scintigraphy in localization of adenomas. Both ultrasonography and scintigraphy used for determining localization, and they located 73 adenomas (91.3%) with sensitivity of 97.3% and PPV of 93.5%.

CONCLUSION: Ultrasonography as an accurate method for localization of enlarged parathyroid glands in primary hyperparathyroidism, is comparable in overall utility with sestamibi scintigraphy. This study suggests a strategy for initial testing with one method, followed by the alternate imaging test if the first test happens to be negative.