Detection and Assessment of Thyroid Carcinoma by using Technicuim 99m and Iodine-131

Abstract

The lack of anatomical details in standard 131 iodine whole body scanning (1311 WBS) interferes with the proper localization of metastatic differentiated thyroid carcinoma (DTC) lesions. In addition, nearby or overlapping variable physiological distribution of 1311 may affect the specificity of 1311 uptake, giving indeterminate results. The aim of this study was to demonstrate the clinical usefulness of simultaneous co-registration of 99m Tc MDP bone scanning as an anatomical landmark with 1311 scanning in the evaluation of metastatic DTC. Material and Methods: Twenty-five patients (16 females and 9 males, mean age + SD = 52 + 13 years) with metastatic DTC (17 papillary, 8 follicular), were included. Whole body scanning were obtained 48 hours after oral administration of 185-370 v MBq 1311 and 2 hours after IV administration of 185-370 MBq 99 mTc MDP. Occasionally, additional simultaneous co-registration of localized detailed images was also performed. The two planar images were fused with optional fusion of SPECT images. Fusion image were considered to improve image interpretation in comparison with standard 1311 scanning when they provided better localization of lesion.