AMINA SAEEDCUI/SP23-RPH-017/LHRDr. Naima AminLHR TP 96372026-03-032024https://repository.cuilahore.edu.pk/handle/123456789/2639It has been long known that patients treated with ionizing radiation carry a risk of developing a second cancer in their lifetimes. A high-energy electron beam 6 MeV through linear accelerator is used to strike the target in cancer treatment. External beam radiotherapy is used to deliver the radiations to the organ. In this study, breast organ selected as a target volume. The breast organs include surrounding tissues/OARs such as brain, lungs, liver, breast, heart. Thus, the purpose of this study is to analyze and calculate the effect of high-energy electrons on these surrounding tissues of breast. This damage is very important to analyze to the functionality of organs. Surrounding tissues affected by the direct and indirect radiation. Both radiation produce chemical changes in DNA. In this study, we investigate the chemical changes at DNA level to analyze the functionality of organ and the effect of radiation in surrounding tissues. More precise dosimetry can be develop by analysis the effect of radiation in target and surrounding tissues for further treatment.enDepartment of PhysicsSP23PhysicsSurrounding TissuesBiological AlterationsCancer TreatmentRadiation AnalysisThesis