Clinical evaluation of 99mTc(V)-dimercapto succinic acid (DMSA) for imaging medullary carcinoma of thyroid and its metastasis.

99mTc(V)-DMSA kits developed by the Radiopharmaceutical Division, Bhabha Atomic Research Centre, have been evaluated for potential use in scanning medullary carcinoma of the thyroid and its metastases. There were 15 patients with proved medullary carcinoma and 6 patients with other differentiated thyroid carcinoma. Amongst the 15 patients with medullary carcinoma, 12 (80%) showed positive localisation either in the primary or one or more metastatic sites. None of the six patients with carcinoma other than medullary showed increased concentration of 99mTc(V)-DMSA. Of the 37 known metastatic sites in 15 patients with medullary carcinoma, 24 showed concentration of 99mTc(V)-DMSA (64.9%). In addition, 99mTc(V)-DMSA concentration was seen in 14 sites where no evidence of metastasis was revealed. The incidence of 99mTc(V)-DMSA concentration in soft tissue and bone metastasis was similar.