Multiparametric Photoacoustic Imaging in the Course of Radiation Therapy of Malignant Head and Neck Tumors

Multispectral photoacoustic imaging enables the measurement of the optical absorption of various tissue components or exogenous contrast agents in vivo. The dominant, near infrared absorbing chromophores in human tissue are oxy- and deoxyhemoglobin followed by collagen, melanin and lipids. The multispectral measurement of the absorption of hemoglobin shows changes in blood oxygen saturation and blood volume. The high resolution of photoacoustic imaging also enables the vascular structure to be displayed. The aim of this exploratory study is to generate hypotheses by applying photoacoustic imaging to the field of head and neck tumor therapy. The next step is to investigate whether and how photoacoustic imaging can help improve diagnostics and better planning of treatments in the future. In particular, the differences between normal and tumor tissue and the changes in the tissue due to radiation therapy using photoacoustic imaging are examined. In the quantitative analysis of the images, measured chromophores, primarily oxygen saturation, blood volume and collagen concentrations at different measuring points are used in the course of the therapy.