Modeling

Medical physics has mastered modeling of particle transport in absorbing and scattering media (e.g., Monte Carlo method), which also applies to transport of incoherent light in biological tissues. Nevetheless, modeling of light interaction with specific tissues and organs remains a challenge, primarily due to their complex structure on different scales, incomplete knowledge of their optical properties, and incompletemunderstanding of physical effects and physiological response to intense laser pulses. Similarly, expansion of modeling expertise to simulations of complex biological systems remains a huge challenge.

The main modeling efforts will be focused on addressing these key problems through developments of:

  • Advanced tissue modeling in biomedical optics: One of the key problems in biomedical optics is to effectively describe complex interactions between incident light (with varying wavelength, polarization, intensity and duration) and different biological tissues and organs. Development of novel optical imaging, diagnostic, and therapeutic applications crucially depends on accurate numeric modeling of optical and thermal transport, as well as biophysical and biochemical processes following the irradiation. The most common approaches involve numerical modeling, which is quite accurate yet computationally very intensive, or application of analytical solutions based on diffusion approximation of light transport. Current models incorporate basic interactions (e.g., absorption, scattering, refraction), but often fail to incorporate other physical processes, such as fluorescence, which can also be clinically relevant. The main goal of our research is to develop accurate and time-efficient optical transport models to predict and optimize the efficacy of new optical imaging modalities and therapeutic protocols. Among the former, we will investigate the potential of diffuse reflectance spectroscopy (DRS), multispectral imaging, and photo-thermal radiometric methods to characterize clinically important tissue properties, such as blood oxygenation, perfusion and concentration of other biologically important molecules. The efficacy of the developed methods will be tested in vitro as well as in vivo.
  • Advanced modeling of tumor growth and response to therapies: Computational models have emerged as powerful and indispensable tools that are paving the way for an era of “personalized” medicine, where every patient, every tumor and every single part of it can be treated individually. We have developed a computational model, capable of simulating tumor response to various treatments (e.g., radiotherapy, anti-angiogenic therapies). The model incorporates pharmacokinetic and pharmacodynamic properties, as well patient-specific molecular imaging data. The main goal of our work is to investigate sensitivity of outcome to key biological parameters and use these models to design more effective and more personalized future therapies.