Lymphoscintigraphy for interpretation of changes of cervical lymph node function in patients with oral malignant tumors: Comparison of Tc-99m-Re and Tc-99m-HSA-D

Objective. The purpose of this study is to compare the usefulness of techne tium-99m-rhenium colloid (Tc-99m-Re) and technetium-99m-human serum albumin diethylene-triamine-pentaacetic acid (Tc-99m-HSA-D) as lymphoscintigraphic agents and to discuss the significance of lymphoscintigraphy in comparison with computed tomography (CT), magnetic resonance imaging (MRI), and ultra sonography (US). Study design, Dynamic and static lymphoscintigraphies were performed with T c-99m-Re and Tc-99m-HSA-D. The usefulness of the 2 agents was evaluated sta tistically in comparison with pathologic findings and palpation. The signif icance of lymphoscintigraphy is discussed in comparison with CT, MRI, and U S (by the literature of CT, MRI, and US). Results, Lymphoscintigraphy was superior to palpation, and Tc-99m-Re was su perior to Tc-99m-HSA-D in accuracy, specificity, and the incidence of true- positive and false-positive. Statistical significance was shown between the static lymphoscintigraphy with Tc-99m-Re and palpation. The reliability of lymphoscintigraphy seemed to be slightly inferior to CT and MRI in specifi city and accuracy. However, lymphoscintigraphy had some advantages that CT and MRI lacked; for example, it showed very high sensitivity (100%) and no false-negative (0%). it also showed changes of lymph node function, showed all levels of neck nodes at one time, and showed a possibility of detecting small lymph node metastases. Conclusion. Lymphoscintigraphy was more useful than palpation in detecting lymph node metastases, and Tc-99m-Re was superior to Tc-99m-HSA-D as an age nt. Lymphoscintigraphy is significant when it is performed as a preliminary examination before CT or MRI.