Comparison of preoperative imaging techniques (thallium technetium scan and ultrasonography) and intraoperative staining (with methylene blue) in localizing the parathyroid glands.

We carried out a prospective study to compare the predictive value of preoperative thallium technetium scan, ultrasound (US) and intraoperative staining of the parathyroid glands (with methylene blue) in patients with parathyroid adenoma, parathyroid hyperplasia, thyroid carcinoma and thyrotoxicosis, in the Istanbul School of Medicine, Department of General Surgery. Methylene blue was given at a dose of 5 mg/kg/body weight in a 500 ml 5% Dextrose +0.9% saline solution 1 hour before surgery. All adenomas (10 patients), hyperplastic parathyroid glands (12 patients) and 45 of 52 suppressed glands (82%) were stained. In patients with thyroid carcinoma (7) and thyrotoxicosis (5), 42 of 48 normal parathyroid glands (87%) were stained. There were no maneuver-related complications. Thallium technetium scan (TT) accurately identified 10 of 10 (100%) parathyroid adenomas and 13 of 26 (50%) hyperplastic parathyroid glands. US successfully localized 10 of 10 (100%) adenomas and 18 of 26 (66%) hyperplastic glands. Neither technique was successful in identifying normal glands. The intraoperative identification of the parathyroid glands with methylene blue was found to be an effective, safe and cost-effective technique which helps the surgeon in the dissection and shows abnormal parathyroid glands more accurately than preoperative imaging techniques.