Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 14, 2015; 21(14): 4210-4215
Published online Apr 14, 2015. doi: 10.3748/wjg.v21.i14.4210
Multiphoton microscopy for tumor regression grading after neoadjuvant treatment for colorectal carcinoma
Lian-Huang Li, Zhi-Fen Chen, Xing-Fu Wang, Shuang-Mu Zhuo, Hong-Sheng Li, Wei-Zhong Jiang, Guo-Xian Guan, Jian-Xin Chen
Lian-Huang Li, Shuang-Mu Zhuo, Hong-Sheng Li, Jian-Xin Chen, Institute of Laser and Optoelectronics Technology, Fujian Provincial Key Laboratory for Photonics Technology, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, Fujian Normal University, Fuzhou 350007, Fujian Province, China
Zhi-Fen Chen, Wei-Zhong Jiang, Guo-Xian Guan, Department of Colorectal Surgery, Fujian Medical University Union Hospital, Fuzhou 350001, Fujian Province, China
Xing-Fu Wang, Department of Pathology, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350001, Fujian Province, China
Jian-Xin Chen, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350007, Fujian Province, China
Author contributions: Li LH, Chen ZF and Wang XF contributed equally to this work; Li LH and Chen JX were responsible for study conception and design; Li LH and Li HS obtained the data; Chen ZF, Wang XF, Zhuo SM, Jiang WZ and Guan GX provided technical support; all authors contributed to analysis and interpretation of data, wrote, reviewed and approved the final manuscript.
Supported by Program for Changjiang Scholars and Innovative Research Team in University, No. IRT1115; the National Natural Science Foundation of China, No. 81271620; the Natural Science Foundation for Distinguished Young Scholars of Fujian Province, No. 2014J06016; the Youth Scientific Research Foundation of Fujian Provincial Department of Health (2013-2-36); and National Clinical Key Specialty Construction Project (General Surgery).
Ethics approval: This study was reviewed and approved by the Fujian Medical University Union Hospital Institutional Review Board.
Informed consent: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest: The authors declare that they have no conflict of interest.
Data sharing: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jian-Xin Chen, PhD, Professor, College of Photonic and Electronic Engineering, Fujian Normal University, No. 8 Shangsan Road, Cangshan District, Fuzhou 350007, Fujian Province, China. chenjianxin@fjnu.edu.cn
Telephone: +86-591-22686078 Fax: +86-591-83465373
Received: November 4, 2014
Peer-review started: November 5, 2014
First decision: November 26, 2014
Revised: January 10, 2015
Accepted: January 21, 2015
Article in press: January 21, 2015
Published online: April 14, 2015
Abstract

AIM: To evaluate the feasibility of using multiphoton microscopy (MPM) to assess a tumor regression grading (TRG) system.

METHODS: Fresh specimens from seven patients with colorectal carcinoma undergoing neoadjuvant radiochemotherapy at the Fujian Medical University Union Hospital were obtained immediately after proctectomy. Specimens were serially sectioned (10 µm thickness) and used for MPM or stained with hematoxylin and eosin for comparison. Sections were imaged by MPM using 810 nm excitation, and images were collected in two wavelength channels corresponding to second-harmonic generation (SHG) and two-photon excited fluorescence (TPEF) signals. The ratio of these signal intensities was used to distinguish fibrosis from normal mucosal and serosal tissues.

RESULTS: TRG of specimens assessed by MPM were in complete agreement with histologic grading performed by a consulting pathologist. SHG and TPEF images clearly revealed collagen fibers and fragmented elastic fibers in the muscularis propria specimens following neoadjuvant radiochemotherapy. Additionally, blood vessel hyperplasia was observed as thickening and fibrosis of the intima and media, which was accompanied by minimal inflammatory cell infiltration. Furthermore, the SHG/TPEF ratio in stromal fibrosis (4.15 ± 0.58) was significantly higher than those in the normal submucosal (2.31 ± 0.52) and serosal (1.47 ± 0.10) tissues (P < 0.001 for both). Analysis of emission spectra from cancerous tumor cells revealed two peaks corresponding to nicotinamide adenine dinucleotide hydrogen and flavin adenine dinucleotide signals; the ratio of these values was 1.19 ± 0.02, which is close to a normal metabolic state.

CONCLUSION: MPM can be used to perform real-time diagnosis of tumor response after neoadjuvant treatment, and can be applied to evaluate TRG.

Keywords: Multiphoton microscopy, Neoadjuvant treatment, Second-harmonic generation, Tumor regression grading, Two-photon excited fluorescence

Core tip: This study evaluated the feasibility of using multiphoton microscopy for the assessment of a tumor regression grading system. Multiphoton microscopy allows diagnostic features of colorectal carcinoma treated with neoadjuvant therapy to be visualized. Quantitative image analyses can be used to distinguish fibrotic tissue from normal submucosal and serosal tissues. This is the first study demonstrating the application of multiphoton microscopy for tumor regression grading.