[The usefulness of MIBI scintigraphy for postoperative monitoring of patients with thyroid cancer].

Metoxyizobutyloizonitrile labelled with technetium 99mTc is a radio-pharmaceutical that was shown to accumulate in benign and cancerous thyroid tissue. As it can be applied without thyroid hormone withdrawal this gave a stimulus to the investigations on its usefulness in diagnostic and follow up procedures for thyroid cancer patients. The goal of this study is to evaluate the efficacy and benefit of 99mTc-MIBI whole body scintigrams in post surgery follow-up of patients with differentiated thyroid cancer. One hundred and twenty eight 99mTc MIBI scintigraphy were performed and evaluated. Sensitivity of MIBI scans was the highest for bone metastases--79%. Good results were also obtained for lymph node metastases (sensitivity--73%, specificity--90%). In case of lung metastases the sensitivity and specificity were 21% and 94% respectively. Sensitivity of detection of clinically apparent recurrent disease in thyroid bed was 70% and specificity of visualization 78%. Results of our study demonstrate that 99mTC-MIBI is valuable tool in follow up of thyroid cancer patients, but can not replace 131I scintygraphy.