DIFFERENTIATION OF BENIGN FROM MALIGNANT NODULES BY ACCUMULATION OF TC-99M PERTECHNETATE USING TL-201 DELAYED SCANS

Thyroid carcinoma usually is characterized by a nonfunctioning or ''co ld'' nodule depicted on the Tc-99m scan, Twelve patients with function ing ''hot'' thyroid nodules underwent thyroidectomy (nine hemithyroide ctomies, two nodulectomies, and one subtotal thyroidectomy). Histologi c examination revealed that five patients (42%) had malignant nodules (papillary carcinoma in two and follicular carcinoma in three). Of the seven patients with benign nodules, five had follicular adenoma and t wo had adenomatous hyperplasia. TI-201 scanning (early and delayed) wa s performed at the same time as Tc-99m scanning, Only one of the seven benign nodules showed accumulation on the delayed TI-201 scan, wherea s all five malignant nodules showed accumulation, The delayed TI-201 s can is useful for the differentiation of benign from malignant nodules that show accumulation of Tc-99m pertechnetate.