Multispectral Optoacoustic Tomography (MSOT) Imaging of Heterogeneity within the Tumor Microenvironment

W.H.P. Driessen, N.C. Burton, J. Claussen, S. Morscher, T. Sardella, D. Razansky, V. Ntziachristos
iThera Medical, DE

Keywords: optoacoustic imaging, tumor oxygenation status, tumor perfusion, treatment monitoring

Summary:

Optoacoustic imaging is based on the generation of ultrasound waves induced by the absorption of light pulses by tissue. During MSOT imaging, an object is illuminated using a near-infrared (NIR) laser at multiple wavelengths to then spectrally resolve distinct absorbers. Absorption by intrinsic tissue chromophores (e.g. oxygenated and deoxygenated hemoglobin, melanin) provides rich anatomical contrast, while signal from exogenously administered contrast agents can be multi-spectrally resolved simultaneously allowing for functional and molecular imaging. In this work we studied three types of heterogeneity within the tumor microenvironment by using a preclinical MSOT whole animal scanner, by visualizing hypoxic pockets within orthotopics tumors without the use of contrast agents; by determining heterogeneity in dynamic contrast enhancement by using the non-targeted perfusion marker ICG and by quantifying the extent of apoptosis in tumors in vivo.