  The system of partial differential equations describing tumor-immune dynamics
with angiogenesis taken into account is presented. For spatially homogeneous
case, the steady state analysis of the model is carried out. The effects of
single photodynamic impact are numerically simulated. In the case of strong
immune response we found that the photodynamic therapy (PDT) gives rise to the
substantial shrinkage of tumor size which is accompanied by the increase of
interleukin-2 concentration. On the contrary, the photodynamic stimulation of
weak immune response is shown to be insufficient to reduce the tumor. These
findings indicate the important role of anti-cancer immune response in the
long-term tumor control after PDT.
