Second and Third Harmonic Generation Imaging of Head and Neck Cancer

This project is an analysis oft the extracellular matrix, i.e. fibrillar collagen of head and neck tumors and healthy tissue with Second and Third Harmonic Generation Imaging (SHG and THG), so called nonlinear optics. Two or three photons are coherently scattered and one photon with only half or one third of the original wavelength is created. SHG and THG are based on endogenous contrasts, do not need exogenous alterations like histologic stainings and are not harmful to biological tissue.

We microscopically analyzed histological samples of head and neck tumors and healthy tissue of several patients (n = 10). The analysis was performed with a light microscope as well as a multiphoton microscope. Via a comparison of histological stainings like Elastica van Gieson and immunohistochemistry (Coll I) with SHG and THG signals of the multiphoton microscope, we could demonstrate that those signals were successfully generated. This was a first qualitative analysis. A quantitative analysis was performed by comparison of forward to backward directed signals, the so called f/b-ratio. This analysis showed clear differences between healthy and malignant tissue. 8 out of 10 tissue samples showed a lower f/b-Ratio in malignant tissue compared to healthy tissue, indicating a higher state of disorder in malignant tissue. This method might be a powerful tool to precisely identify malignant tissue and to interpret borders of tumor resection in vivo.

Poster-PDF A-1505.PDF

Publication History

Article published online:
10 June 2020