Photodynamic diagnosis with 5-aminolevulinic acid for intramucosal gastric cancer using green light
Photodynamic diagnosis with 5-aminolevulinic acid for intramucosal gastric cancer using green light
复制标题
5-氨基乙酰丙酸绿光光动力诊断粘膜内胃癌
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
K. Awazu
中科院分区：
文献类型：
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作者：
Daisuke Ihara;H. Hazama;T. Nishimura;K. Awazu
利用5-氨基乙酰丙酸（ALA）诱导的原卟啉IX（PpIX）光动力学诊断（PDD）为胃癌的诊断提供了一种判断浸润深度的方法。基于ALA的PDD的激发光根据其波长通过粘膜组织的吸收和散射而衰减，并且差异包含荧光团深度信息。为了实现粘膜内癌浸润深度的估计方法，本研究考察了两种激发波长之间衰减率的差异。考虑到粘膜和PpIX的光学性质，使用数值模型估计含有PpIX的癌症的浸润深度与从粘膜检测到的荧光强度比之间的关系。还使用由含有PpIX的环氧树脂制成的颗粒进行实验。分别使用具有相同功率密度的波长405和505 nm的激发光照射放置在距粘膜表面0 mm、1.0mm和1.7mm的荧光团深度处的颗粒，以获得荧光图像，并评价图像的平均荧光强度。数值计算和实验结果表明，通过比较荧光图像与波长为405和505 nm的激发光，可以估计PpIX荧光源的荧光团深度。
Photodynamic diagnosis (PDD) of gastric cancer with protoporphyrin IX (PpIX) induced by 5-aminolevulinic acid (ALA) will lead to a method to estimate the invasive depth. The excitation light for ALA-based PDD is attenuated by absorption and scattering of the mucosal tissue according to its wavelength and the difference contains the fluorophore depth information. To realize the method to estimate the invasive depth for the intramucosal cancer, this study investigated the differences of the attenuation rate between two excitation wavelengths. Considering the optical properties of mucosa and PpIX, relationships between the invasive depths of cancer containing PpIX and the fluorescence intensity ratios detected from the mucosa were estimated using a numerical model. An experiment was also performed using a pellet made of epoxy resin containing PpIX. The excitation lights with wavelengths of 405 and 505 nm having the same power density were each used to irradiate the pellet placed at the fluorophore depth of 0 mm, 1.0 mm, and 1.7 mm from the mucosal surface to obtain fluorescence images, and the average fluorescence intensities of the images were evaluated. The numerical and experimental results suggested the possibility to estimate the fluorophore depth of the PpIX fluorescence source by comparing the fluorescence images with excitation lights at wavelengths of 405 and 505 nm.