Radionuclide thyroid angiography and surgical correlation. A five-year study.

Only 15% to 25% of cold nodules on conventional static thyroid scans are malignant. Radionuclide angiography of the thyroid and conventional static scans using sodium pertechnetate Tc 99m were performed on 114 patients who underwent thyroid surgery within a five-year period. The combined use of radionuclide angiography and conventional static scans increased the specificity for the diagnosis of thyroid carcinoma from 42% to 79% over static scans alone. The incidence of carcinoma in solitary cold nodules in our population was increased from 26% on static scans to 60% if the lesion was hypervascular on radionuclide angiography. Eighty-seven percent of hypervascular solitary cold nodules were neoplasms (carcinomas and adenomas). Hypervascularity as demonstrated by radionuclide angiography is predictive of thyroid neoplasia. The finding of a hypervascular, solitary cold nodule makes a recommendation for surgery predictive and reasonable.