Photodynamic Diagnosis for the Identification of Intestinal-Type Gastric Cancers and High-Grade Adenomas

Abstract

Gastric cancer is the second most common cancer in Japan. The incidence of gastric cancer remains high owing to the increase in the elderly population. Endoscopy outperforms radiography in identifying early gastric cancer (EGC). Furthermore, image-enhanced endoscopy (IEE) has been developed and implemented worldwide in clinical practice. Magnifying IEE images can help to visualize the microvascular pattern and microstructure architecture, which is used for the characterization of EGC. However, accurate endoscopic diagnosis requires the experience and skill of endoscopists, making an objective and simple diagnostic method desirable. In this retrospective study, we investigated the diagnostic yield of 5-aminolevulinic acid (5-ALA)-mediated photodynamic diagnosis (PDD) for identifying gastric cancers and high-grade adenomas. In total, 52 lesions from 43 patients were ultimately included in the study. We detected 5-ALA-mediated protoporphyrin IX fluorescence in 45 of the 52 lesions that were initially intended for PDD, resulting in a detection rate of 86.5%, whereas each signet ring cell carcinoma was negative using 5-ALA PDD. In eight of the patients with multiple lesions, 17 lesions were identified using 5-ALA PDD. Again, we took biopsies from six areas that we suspected as new lesions. While 4 lesions were gastric neoplasms resected by endoscopic submucosal dissection, two other lesions were normal. Preoperative 5-ALA-PDD could provide additional diagnostic yields to detect such multiple lesions simultaneously. No severe adverse events were observed. Prospective multicenter studies are warranted to confirm the usefulness of 5-ALA PDD for EGC identification.

Current status and future perspective of linked color imaging for gastric cancer screening: a literature review

“…Therefore, it is desirable to develop an endoscopic diagnostic method that enables objective evaluation to assist in detecting lesions that is not dependent on the endoscopist’s skill. Photodynamic endoscopic diagnosis (PDED) is based on the fluorescence of photosensitizers that accumulate in tumors, which enables objective evaluation independent of the endoscopist’s experience and is useful for tumor detection [ 88 , 89 ]. However, PDED is still a challenging field, and further study should be conducted to demonstrate its usefulness.…”

Research trends in endoscopic applications in early gastric cancer: A bibliometric analysis of studies published from 2012 to 2022

“…As an optical diagnostic method for identifying tumors, photodynamic diagnosis (PDD) involves first the administration of specific photosensitizers (PSs), including verteporfin, talaporfin, and 5-aminolevulinic acid (5-ALA), among which 5-ALA is the most suitable and widely used ( 58 ). These subsequently accumulate in tumors, and can be illuminated with light of a specific wavelength, enabling visualization of the tumors by fluorescence ( 59 ). Raman spectroscopy is a molecular vibrational spectroscopy method that may also be used to diagnose malignancies in vivo .…”

5-Aminolevulinic Acid-Induced Protoporphyrin IX Fluorescence Imaging for Tumor Detection: Recent Advances and Challenges

“…However, there are still many challenges to be addressed before the technique can be applied in clinical practice. PpIX fluorescence navigation is reported to result in good visualization and detection of intestinal-type gastric cancers and high-grade adenomas, and the sensitivity of the former was reported to be 93.3% [ 12 , 91 , 95 , 96 ]. In contrast, the sensitivity of 5-ALA-PDD for diffuse-type gastric cancers, such as signet-ring cell carcinoma, is low, which hampers its clinical application in gastric cancer diagnosis.…”