The Effect of Irradiation on the Skin upon Breast Cancer Radiotherapy Studied by FTIR Spectroscopy

Abstract

Breast cancer affects the female population worldwide. Radiotherapy (RT) is part of the therapeutic modality in the management of breast cancer, after radical mastectomy or conserving surgery. The FTIR spectroscopic “marker bands” will lead us to approach the mechanism of skin damage due to the interaction of ionizing radiation and skin, on a molecular level at the very early stages. FT-IR spectroscopy, breast digital pictures, and ImageJ software were used in the study. Healthy breast skin was irradiated <em>ex-vivo</em> with a 4 Gy dose of a γ-<sup>60</sup>Co course Gammachamber 4000A. The FT-IR spectra showed that the low-dose irradiation induces skin dehydration, collagen secondary structure changes and advanced glycation end products (AGEs) as a result of free radicals as mediated products. The infrared “marker bands” at about 1743, 1160, and 870 cm<sup>-1</sup> are characteristic, indicating the development of inflammation, glycations, and peroxidations respectively, due to ionizing radiation-induced oxidative stress. ImageJ analysis provided the sharp surface of the skin after RT irradiation in contrast to the smooth surface of the non-irradiated healthy skin. The most important damages, induced by radiotherapy, were connective tissue lesions, glycosylation, and phosphorylation processes in the skin. The reactive oxygen species (ROS) free radicals prefer to abstract H atoms from lipids, sugar rings of glycoproteins, and base ribose of DNA. The produced intermediate free radicals, as a result of ROS reactions, led to the formation of AGEs and peroxides.