Comparison of TC-99M sestamibi with I-131 whole Body Scans in Differentiated Thyroid Carcinoma Patients

This study evaluated the potential of Tc-99m sestamibi whole body scan as an alternative to whole body I-131 scan for well differentiated thyroid cancer patients prior to I-131 ablation and post ablation states. We evaluated 115 patients with differentiated thyroid cancer who had total or near total thyroidectomy. All patients had undergone Tc-99m sestamibi whole body scanning high resolution neck ultrasonography prior to conventional I-131 whole body scanning, thyroglobulin and antithyroglobulin values measured. Also all patients had neck and chest CT without contrast agent. The results showed that Tc-99m sestamibi whole body images are highly sensitive and specific in differentiated thyroid carcinoma patients without thyroid supression (T4-off), compared to conventional I-31 whole body scans (kappa=0.68 p<0.001). Neck USG with Tc-99m sestamibi is comparable with conventional iodine based whole body studies also compared to high döşe post-ablation 6th day I-131 whole body scans. Neck USG increases sensitivity and decreases specificity of Tc-99m sestamibi scans. Clinical investigations had to be made to evaluate the efficiency of Tc-99m sestamibi in patients receiving thyroid supression.