DIAGNOSTIC APPLICATION OF MULTIPHOTON MICROSCOPY IN EPITHELIAL TISSUES

Epithelial cancer comprises more than 85%of human cancers.The detection and treatment at the early stage has been demonstrated to apparently improve patient survival.In this review,we summarize our recent research works on the diagnostic application of epithelial tissue based on multiphoton microscopy(MPM),including identification of the layered structures of esophagus,oral cavity,skin and bronchus tissues,establishment of the diagnostic features for distinguishing gastric normal tissue from cancerous tissue,linking collagen alteration and ectocervical epithelial tumor progression for evaluating epithelial tumor progression,and differentiating normal,inflammatory,and dysplastic ectocervical epithelial tissues.These results provide the groundwork for developing MPM into clinical multiphoton endoscopy.

DISTINGUISHING BETWEEN HYPERPLASTIC AND ADENOMATOUS POLYPS AND NORMAL COLONIC MUCOSA BY USING MULTIPHOTON LASER SCANNING MICROSCOPY

Precisely distinguishing between hyperplastic and adenomatous polyps and normal human colonic mucosa at the cellular level is of great medical significance.In this work,multiphoton laserscarming microscopy(MPLSM)was used to obtain the high.-contrast images and the morpho-logical characteristics from normal colonic mucosa,hyperplastic polyps and tubular adenoma.Byintegrating the length and area measurement tools and computing tool,we quantified thedifference of crypt morphology and the alteration of nuclei in normal and diseased human colonicmucosa.Our results demonstrated that the morphology of crypts had an obvious tendency tocystic dilatation or elongated in hyperplastic polyps and tubular adenoma.The cont ent andnumber of mucin droplets of the scattered goblet cells had a piecemeal reduction in hyperplastic polyps and a large decrease in tubular adenoma The nuclei of epithelial cells might be elongated and pseudostratified,but overt dysplasia was absent in hyperplastic polyps.Nevertheless,thenuclei showed enlarged,crowded,stratified and a rod-like structure,with loss of polarity intubular adenoma.These results suggest that MPLSM has the capacity to distinguish betweenhyperplastic and adenomat ous polyps and normal human colonic mucosa at the celular level.

NON-LINEAR SPECTRAL IMAGING MICROSCOPY STUDIES OF HUMAN HYPERTROPHIC SCAR

Skin scar is unique to humans,the major significant negative outcome sustained after thermal injuries,traumatic injuries,and surgical procedures.Hypertrophic scar in human skin is investigated using non-linear spectral imaging microscopy.The high contrast images and spectroscopic intensities of collagen and elastic fibers extracted from the spectral imaging of normal skin tissue,and the normal skin near and far away from the hypertrophic scar tissues in a 10-year-old patient case are obtained.The results show that there are apparent differences in the morphological structure and spectral characteristics of collagen and elastic fibers when comparing the normal skin with the hypertrophic scar tissue.These differences can be good indicators to differentiate the normal skin and hypertrophic scar tissue and demonstrate that non-linear spectral imaging microscopy has potential to noninvasively investigate the pathophysiology of human hypertrophic scar.

Post-operative anastomotic leakage and collagen changes in patients with rectal cancer undergoing neoadjuvant chemotherapy vs chemoradiotherapy

Background A significant difference in the anastomotic leakage(AL)rate has been observed between patients with locally advanced rectal cancer who have undergone preoperative chemotherapy and those undergoing preoperative chemoradiotherapy.This study aimed to quantitatively analyse collagen structural changes caused by preoperative chemoradiotherapy and illuminate the relationship between collagen changes and AL.Methods Anastomotic distal and proximal“doughnut”specimens from the Sixth Affiliated Hospital of Sun Yat-sen University(Guangzhou,China)were quantitatively assessed for collagen structural changes between patients with and without preoperative radiotherapy using multiphoton imaging.Then,patients treated with preoperative chemoradiotherapy were used as a training cohort to construct an AL–SVM classifier by the Mann–Whitney U test and support vector machine(SVM).An independent test cohort from the Fujian Province Cancer Hospital(Fuzhou,China)was used to validate the AL–SVM classifier.Results A total of 207 patients were included from the Sixth Affiliated Hospital of Sun Yat-sen University.The AL rate in the preoperative chemoradiotherapy group(n=107)was significantly higher than that in the preoperative chemotherapy group(n=100)(21.5%vs 7.0%,P=0.003).A fully quantitative analysis showed notable morphological and spatial distribution feature changes in collagen in the preoperative chemoradiotherapy group.Then,the patients who received preoperative chemoradiotherapy were used as a training cohort to construct the AL–SVM classifier based on five collagen features and the tumor distance from the anus.The AL–SVM classifier showed satisfactory discrimination and calibration with areas under the curve of 0.907 and 0.856 in the training and test cohorts,respectively.Conclusions The collagen structure may be notably altered by preoperative radiotherapy.The AL–SVM classifier was useful for the individualized prediction of AL in rectal cancer patients undergoing preoperative chemoradiotherapy.

多光子显微技术在乳腺癌预后预测的应用

乳腺癌是全世界最广泛的女性癌症类型,同样也是女性癌症死亡的主要原因。2020年乳腺癌发病数已经超过肺癌,成为了全球第一大癌。多光子显微技术(MPM)是基于激光与生物组织相互作用发生的多光子激发荧光和谐波等非线性光学效应的一种先进医学成像技术。多光子显微技术不但在成像分辨率上具有与组织病理学分辨率相当的优势,而且具有无标记、免切片、光学层析成像、反映细胞的功能代谢信息、三维靶向消融能力、较低的光漂白与光损伤、高成像对比度等优势。因此,多光子显微技术在医学病理诊断,特别是肿瘤病理诊断临床转化的基础研究和应用研究领域一直受到广泛的关注。本文详细阐述了多光子显微技术在乳腺肿瘤微环境预后预测研究中的应用进展,并展望了其未来发展前景。