Preliminary study of photodynamic diagnosis using 5-aminolevulinic acid in gastric and colorectal tumors

Figure 1 Flow chart of the study. 5-ALA: 5-aminolevulinic acid; ESD: Endoscopic submucosal dissection; EMR: Endoscopic mucosal resection.

Figure 2 Early gastric cancer with fluorescence. A: Endoscopic image; B: Endoscopic image obtained after the spraying of indigo carmine dye; C: Resected specimen irradiated by white light; D: Resected specimen showing fluorescence.

Figure 3 Spectral reflectance in the range of 400-800 nm obtained using a hyperspectral camera. Two reflectance peaks in the tumor were detected at 635 and 700 nm; this bimodal reflectance is the characteristic reflectance pattern of protoporphyrin IX.

Figure 4 Early colorectal cancer with fluorescence. A and B: Endoscopic images; C: Resected specimen irradiated by white light; D: Resected specimen showing fluorescence.