Making the best use of our previous results as a clue for interpreting kinetics of scintigraphic agents

Summary now, we have performed scintigraphy with 201-thallium chloride (201-TlCl) and 99m-Tc-hexakis-2-methoxy-isobutyl-isonitrile (99m-Tc-MIBI) for malignant tumors and lymphoscintigraphy with 99m-Tc-rhenium-colloid (99m-Tc-Re) and 99m-Tc-human-serum-albumin-diethylene-triamine-penta-acetic-acid (99m-Tc-HSA-D) for lymph node metastasis. In this article, we re-evaluated scintigraphic images retrospectively with a hope that the results might be a clue, even if it is small, for dentists to try to improve the accuracy of diagnosis of malignant tumors. From scintigraphy, we obtained the tumor retention index as a factor to estimate the uptake of radioactive agents in tumor cells. Moreover, we estimated transport proteins of Na+/K+-ATPase and permeability-glycoprotein (P-gp) expressed on the cell membrane that might regulate the kinetic condition of radioactive agents. Among the tumor retention index, the transport protein and the histopathologic finding of tumors, there were relatively well correlations. The tumor retention index showed a difference clearly between malignant tumor and benign tumor. The transport protein revealed a distinct expression in accordance with the malignancy of tumor, and the uptake clearly depended upon the expression of transport protein. Moreover, the lymph node metastasis was detected well by lymphoscintigraphy with 99m-Tc-Re and 99m-Tc-HSA-D.