Analyzing the Fractal Spectrum Behavior of Human Umbilical Vein Endothelial Cells in Response to Ionizing Photon Beams for Two Modalities of Single Irradiation and Fractionation Radiotherap

Previous studies have illustrated that each physiological change in blood supply following the ionizing beam irradiation is caused by damaging the inner wall of vessels, which is attributed to changes in the cytoskeleton in the endothelium layer. The aim of this study is to investigate the effect of radiotherapy on the fractal dimension parameter of endothelial cells as a biomarker of the cytoskeleton following the single irradiation and fractionation radiotherapy.

Methods and Materials: 

In this study, human umbilical vein endothelial cells (HUVECs) were irradiated by the doses of 0, 2, 4 and 8 Gy by using cobalt-60 therapeutics machine in two situations of single continuous irradiation and fractionation radiotherapy. The cytoskeleton of each group was separately stained within 24 hours after irradiation. Then, the fractal dimension spectrum was performed for each radiation-induced group by processing the confocal microscopy images with the related command in the ImageJ software package.

The results showed that the fractal dimension parameter of endothelial cells is significantly changed following the external radiotherapy in two modes of single and fractionation irradiation modalities. Moreover, the reduction of this parameter for the fractionation radiation treatments is statistically higher than that following the continuous irradiation for the same radiation dose.

Assessing the fractal dimension can be considered as a reliable secondary index for the prognosis of the response of human umbilical vein endothelial cells to radiotherapy with two procedures of single and fractionation modalities.