Demonstration of Ex-Vivo Evaluation for Gastric Cancer Onset Using Laser-Induced Photoacoustic Vibration

The metastatic strategy of a cancer will be determined by the relative stiffness of the cancer tumor and the surrounding normal tissue, i.e. hard relative to the surrounding tissues push off, while those that are soft invade into the gaps. Therefore, it is necessary to detect differences in elastic properties from surrounding tissues specific to malignant tumors. This concept has been proposed and studied as Physical oncology [1]. We have been developed a novel method to estimate Young's modulus for soft tissue, agarose gel, by laser irradiation and induced-photoacoustic vibration analysis [2]. In this study, a novel elastography scheme for soft-tissue in vivo to replace the physician's palpation by applying the photoacoustic vibration generation by non-invasive laser irradiation. In this presentation, we report on the detection of cancer tumor onset by the audible frequency range for agarose gel phantoms of different Young's modulus and excised stomachs to detect differences in stiffness.