Real-time optical diagnosis for gastric cancer with serosal invasion using multiphoton imaging

Jun Yan, MD¹, Yu Zheng¹, Xiaoling Zheng¹, Fangqin Xue², Gang Chen³, Jianping Lu³, Guoxin Li¹. ¹Department of General Surgery, Nanfang Hospital, Southern Medical University, ²Department of Surgery, Fujian Provincial Hospital, ³Department of Pathology, Fujian Provincial Tumor Hospital

Background: Real-time optical imaging which can show tissue histopathology will be of extraordinary benefit to staging laparoscopy in gastric cancer with serosal invasion requiring down-stage treatment. The purpose of this study was to evaluate the feasibility of using multiphoton imaging to make real-time optical diagnosis for gastric cancer with or without serosal invasion.

Methods: Thirty fresh, unfixed, and unstained full-thickness gastric specimens underwent multiphoton imaging and then went through routine pathological procedure. Multiphoton images were compared with golden standard hematoxylin-eosin (H-E) stained images.

Results: Multiphoton images were acquired by two channels: broadband autofluorescence from cells, and second harmonic generation (SHG) from tissue collagen. Peak multiphoton autofluorescence intensity was detected in serosa excited at 800 nm. There were significant differences between gastric cancer without serosal invasion and gastric cancer with serosal invasion. In gastric cancer without serosal invasion, multiphoton imaging revealed regular collagen structure (Fig. A). In gastric cancer with serosal invasion, multiphoton imaging demonstrated irregular collagen structure, and cellular and nuclear pleomorphism (Fig. B). Cancer cells were characterized by irregular size and shape, enlarged nuclei, and increased nuclear-cytoplasmic ratio. SHG signals significantly decreased in gastric cancer with serosal invasion, compared with gastric cancer without serosal invasion.

Conclusions: It is feasible to use multiphoton imaging to make real-time optical diagnosis for gastric cancer with or without serosal invasion. With integration of laparoscopy, multiphoton imaging has the potential to provide real-time in-situ optical diagnosis and guide down-stage treatment for gastric cancer with serosal invasion.

Key words: Multiphoton imaging; Real-time optical diagnosis; Gastric cancer; Serosal invasion; Pathology.