Nonsensitized photoinduced destruction of tumor in experiments

Abstract

The sizeable damage of tumor (Pliss lymphosarcoma) were detected on intact rats (without the photosensitizer injection) after laser excitation (λ=627.8 nm or λ=671 nm). The model is suggested to calculate the absolute and relative sizes of the tumor node necrosis and the area of the histotopographic section. The photon distribution between photosensitizer and hemoglobin molecules is calculated for the typical PDT conditions. We suppose that some non-photodynamic reactions activated by light are responsible for the observed photodestructive effect on intact tumors. The contribution of these reactions to the tumor damage in PDT treatments is considerable and it cannot be neglected.