Real-time Histological Evaluation of Gastric Cancer Tissue by Using a Confocal Laser Endomicroscopic System

Abstract

Background/Aim: The need for instant histological evaluation of fresh tissue, especially in cancer treatment, remains paramount. The conventional frozen section technique has inherent limitations, prompting the exploration of alternative methods. A recently developed confocal laser endomicroscopic system provides real-time imaging of the tissue without the need for glass slide preparation. Herein, we evaluated its applicability in the histologic evaluation of gastric cancer tissues. Materials and Methods: A confocal laser endomicroscopic system (CLES) with a Lissajous pattern laser scanning, was developed. Fourteen fresh gastric cancer tissues and the same number of normal gastric tissues were obtained from advanced gastric cancer patients. Fluorescein sodium was used for staining. Five pathologists interpreted 100 endomicroscopic images and decided their histologic location and the presence of cancer. Following the review of matched hematoxylin and eosin (H&E) slides, their performance was evaluated with another 100 images. Results: CLES images mirrored gastric tissue histology. Pathologists were able to detect the histologic location of the images with 65.7% accuracy and differentiate cancer tissue from normal with 74.7% accuracy. The sensitivity and specificity of cancer detection were 71.9% and 76.1%. Following the review of matched H&E images, the accuracy of identifying the histologic location was increased to 92.8% (p<0.0001), and that of detecting cancer tissue was also increased to 90.9% (p<0.001). The sensitivity and specificity of cancer detection were enhanced to 89. 1% and 93.2% (p<0.0001) . Conclusion: High-quality histological images were immediately acquired by the CLES. The operator training enabled the accurate detection of cancer and histologic location raising its potential applicability as a realtime tissue imaging modality.Instant histological evaluation of fresh tissue is crucial for effective cancer treatment, involving detection of tumor cells and ensuring resection with clear margins. However, the conventional frozen section technique, currently employed for this purpose, presents inherent limitations, such as processing time and suboptimal slide quality, due to preparation artifacts (1). Despite efforts to address these limitations, alternative methods have not gained widespread adoption in clinical practice. One such attempt involves magnifying narrow-band imaging, utilizing dual-wavelength light to distinguish cancerous and normal gastric tissue based on distinct emission patterns of microvasculature and mucosa (2). Nevertheless, challenges remain, particularly in accurately identifying pale-colored lesions with superficial flat morphology and histologically undifferentiated cancer. 855