The Effect of Neck Physical Examination and Signing Thyroid Nodules by Lead Marker on 99mTcO4 Thyroid Scan Results

Thyroid nodules are of the most common thyroid diseases found in about half of adults. Diagnosis of nodules is clinically important because of the risk of cancer. Thyroid gland radionuclide scanning with 99mTcO4 helps the physician to choose better approach to the disease, knowing the activity of the nodule. Neck physical examination before scintigraphy and using a piece of lead marker specifies the location of the nodule in the scintigram to give a more distinct interpretation of the report of the scan. 117 patients with thyroid nodules referred to Seyyed Alshohada Hospital Nuclear Medicine Center (Isfahan, Iran) during 2012-2013 were studied. The patients underwent scanning with 99mTcO4 once; the next time, physical examination of the neck was done and then, scanning was applied; and for the last time, we put a lead marker on the palpated nodule in physical examination, then did the radionuclide scanning. The reports of three scanning tests were compared together. Regarding chi-square test, physical examination of neck and using a lead marker on the palpated thyroid nodule affected the reporting of the scintigram and caused reduction of the false-positive results in both cold and warm nodules (P < 0.05). Also regarding to Wald test, using both mentioned methods resulted in less mistakes in interpretations of the reports of the thyroid scanning. This study showed that, as a simple cost effective method, physical examination of thyroid gland and using lead marker through scintigraphy may be useful in diagnosis of thyroid nodules.