HEMORHEOLOGICAL AND MICROCIRCULATORY DYNAMICS DURING BREAST CANCER RADIOTHERAPY

Abstract

Background. Radiation therapy is an essential component of multimodal breast cancer treatment. Despite its proven clinical efficacy, irradiation may induce vascular dysfunction, oxidative stress, microcirculatory disturbances, and alterations in blood rheology. Erythrocyte deformability and aggregation are key determinants of microvascular blood flow and tissue perfusion and may therefore serve as potential biomarkers of radiation-induced vascular impairment. Objective. To evaluate the dynamics of hemorheological parameters in patients with left-sided breast cancer during radiation therapy and assess their potential significance as markers of microcirculatory dysfunction. Materials and Methods. A prospective observational study included 42 patients with histologically confirmed left-sided invasive ductal breast carcinoma undergoing postoperative external beam radiation therapy. Seventeen age-matched healthy females served as controls. Radiation therapy was delivered using conventional fractionation with a daily dose of 2 Gy and a total focal dose of 45–50 Gy. Hemorheological parameters, including erythrocyte deformability and erythrocyte aggregation, were assessed before irradiation, on day 8, and on day 16 after initiation of treatment. Statistical analysis was performed using repeated measures ANOVA with post hoc pairwise comparisons. Results.   Progressive deterioration of hemorheological parameters was observed during radiation therapy. Erythrocyte deformability significantly decreased from 1.86 ± 0.15 before treatment to 1.29 ± 0.18 after 16 days of irradiation (p < 0.001), whereas erythrocyte aggregation increased from 27.4 ± 2.1 to 36.9 ± 3.2 (p < 0.001). The most pronounced changes were detected after 16 irradiation sessions, indicating progressive impairment of blood rheology and microcirculatory function. Conclusion. Radiation therapy in patients with breast cancer is associated with progressive impairment of erythrocyte deformability and enhanced erythrocyte aggregation. These hemorheological disturbances may reflect early microcirculatory and vascular dysfunction during treatment. Monitoring hemorheological parameters may therefore provide additional information for early detection of radiation-associated vascular impairment.