Usefulness of Autofluorescence Imaging for Estimating the Extent of Gastric Neoplastic Lesions: A Prospective Multicenter Study

BACKGROUND/AIMS: The aim of this study was to determine whether the margin of early to be detected gastric cancer (EGC) and gastric adenoma is easier to be detected with autofluorescence imaging (AFI) than with white-light endoscopy (WLE). METHODS: A total of 102 lesions (48 EGCs and 54 gastric adenomas) found in 98 patients were removed endoscopically or surgically. The measured length of each pathology specimen was compared with the lengths estimated using WLE, AFI, and chromoendoscopy. RESULTS: The lesions could be discriminated from surrounding mucosa by AFI in 86 cases (84.3%). The detection rates were similar for elevated lesions (85.1%) and flat/depressed lesions (82.9%, p=0.770). In terms of histology, the detection rate was slightly higher for adenomas (90.7%) than for cancer (77.1%, p=0.058). The estimated length was shorter than the pathologic length in 31.4% of cases when using WLE and 22.1% of cases when using AFI (p=0.168). The resection range was larger for EMR than for AFI in 24 of 80 cases (30.0%). CONCLUSIONS: WLE tends to underestimate the size of EGCs, whereas AFI tends to overestimate their size.

Endoscopic Photodynamic Diagnosis (PDD) Using Oral 5-aminolevulinic Acid in Gastrointestinal Cancer and Dysplastic Lesions / 대한소화기내시경학회지

BACKGROUND/AIM: Endoscopic screening for the detection of premalignant high-grade dysplasia remains time consuming and is subject to sampling error. We performed this study to determine the clinical usefulness of laser endoscopic spectra analyzer (LESA-7) in gastrointestinal cancer and dysplastic lesions. METHODS: Seventeen patients with histologically proven carcinoma or adenoma with or without high-grade dysplasia were treated with oral administration of 5-ALA (20 mg/kg). PDD was performed 4 hours later. The fluorescence was excited by a helium-neon laser with emission at 637 nm. The generated fluorescence light was collected and fed into a multi-channel analyzer and the full spectrum was displayed in real time (LESA-7). RESULTS: In most of malignant tumors, a clear protoporphyrin IX-related dual-peaked fluorescence signal at about 635 and 700 nm was identified in the fluorescence spectra. However, it was not fully identified in bile duct cancers. In PDD of post-EMR in order to detect residual lesions (gastric flat adenoma 1, early gastric cancer 2), a dual spectra was not identified. CONCLUSIONS: PDD with 5-ALA might be useful for the detection of dysplasia and carcinoma in the gastrointestinal tract.