Peculiarities of Blood Circulation and Rheological Properties During the Treatment of Cancer Disease

Abstract

Neoplasms are characterized by an abnormal, altered stroma that facilitates can- eoplasms are characterized by an abnormal, altered stroma that facilitates cancer development by providing nutritional support and establishing a barrier for er development by providing nutritional support and establishing a barrier for host defense mechanisms. During a malignant disease all physiological processes ost defense mechanisms. During a malignant disease all physiological processes of destruction require structural changes, that manifest at different organization f destruction require structural changes, that manifest at different organization levels in organs, tissues, single cells, and cellular organelles. All of these struc- evels in organs, tissues, single cells, and cellular organelles. All of these structures have speci ures have specifi c and signi c and signifi cantly complex rheological parameters. In a given cantly complex rheological parameters. In a given vessel within a tumor, blood essel within a tumor, blood fl ow fl uctuates with time and can reverse its direc- uctuates with time and can reverse its direction. Elevated geometric and viscous (rheological) resistance and other molecu- ion. Elevated geometric and viscous (rheological) resistance and other molecular and mechanical factors contribute to this spatial and temporal heterogeneity. ar and mechanical factors contribute to this spatial and temporal heterogeneity. Heterogeneity contributes to both acute and chronic hypoxia in tumors - a maeterogeneity contributes to both acute and chronic hypoxia in tumors - a major cause of resistance to radiation and other therapies. adsorption-rheological or cause of resistance to radiation and other therapies. adsorption-rheological properties of blood prognostic signi roperties of blood prognostic significance concerning lung neoplasm course cance concerning lung neoplasm course and development of complications of chemoradiation respectively. Intravascu- nd development of complications of chemoradiation respectively. Intravascular rheological changes are one of the most important factors to explain the ar rheological changes are one of the most important factors to explain the radiobiological principles of SBRT. Laboratory studies suggest that the radiation response for the high-dose single fractions used in radiosurgery is predominant- esponse for the high-dose single fractions used in radiosurgery is predominantly related to the supporting endothelial cells. The Linear Quadratic Model (LQ y related to the supporting endothelial cells. The Linear Quadratic Model (LQ Model) applies to the calculation of iso-effect doses in treating with conven- odel) applies to the calculation of iso-effect doses in treating with conventional EBRT. Based on the LQ and USC model, we estimated the Biologically ional EBRT. Based on the LQ and USC model, we estimated the Biologically Effective Dose (BED) and Equivalent Dose. When the fractional dose is higher ffective Dose (BED) and Equivalent Dose. When the fractional dose is higher than the Transient Dose, the LQ model is inappropriate to predict the effects han the Transient Dose, the LQ model is inappropriate to predict the effects induced by radiation. BED is calculated by the LQ formula if the dose per frac- nduced by radiation. BED is calculated by the LQ formula if the dose per fraction is below the transition dose – DT and by the USC formula if the dose per ion is below the transition dose – DT and by the USC formula if the dose per fraction is higher than DT.