201ti scintigraphy in postoperative detection of thyroid cancer: a comparative study with 131i

201TI scintigraphy was performed to visualize malignant lesions postoperatively in 28 patients with thyroid cancer. The results were compared with those of 131 I and/or 99mTc pertechnetate scintigraphy. Of eight patients who had malignant lesions and no normal thyroid tissue, 201TI concentration was observed in seven, while 131I concentration was observed in only three. All of four patients who had malignant lesions and did have remaining normal thyroid tissue showed concentrations of 201TI. 201TI scintigraphy can be performed without any preparation and may be useful in depicting residual and recurrent lesions regardless of the presence of normal thyroid tissue.