Ultrasonic Heating Detects Lipiodol Deposition within Liver Tumors after Transarterial Embolization: An In Vivo Approach

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K20716
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 90130:Medical systems-related
• Research Institution: Nara Medical University
• Principal Investigator: Saito Natsuhiko 奈良県立医科大学, 医学部附属病院, 研究員 (30790290)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 超音波加温 / 組織性状診断 / 組織定量化 / 癌治療効果判定

Outline of Final Research Achievements

The accumulation of Lipiodol after transarterial embolization is known to reflect tumor necrosis. In general, the treatment effect is evaluated by computed tomography. However, there is a problem of radiation exposure. The purpose of this study was to evaluate the efficacy of using the rate of change in sound velocity caused by ultrasonic heating to reflect Lipiodol accumulation after TAE in a rat liver tumor model. We analyzed the association of this developed technique with CT images and histological findings. Eight rats bearing N1S1 cells were prepared. After confirmation of tumor development in a rat liver, Lipiodol was injected via the hepatic artery. Seven days after TAE, CT scan and sound velocity changes caused by ultrasonic heating were measured, and then the rats were sacrificed. In the result, the correlation between CT value and histological analysis was similar to that of ultrasonic heating and histological analysis. From the results, this technique can replace CT.

Free Research Field

放射線医学・IVR学

Academic Significance and Societal Importance of the Research Achievements

TACE後の効果判定として長い間CTしか使用されてこなかったこの分野で、新たな評価方法が使用できる可能性が出たのは非常に学術的に有益な点である。CTは被曝の問題があるが、超音波はその心配がない点でも画期的な発見である。
また癌患者は一度癌を発症すると、終生に渡りフォローアップの画像診断を受けなくてはならない患者が多く、医療コストやひっ迫する検査数を緩和するためにも、超音波加温による診断法が普及すれば有益である。