Dosimetry Audit for Precise Radiotherapy Treatment Planning by Using High-Energy Electron Beam (6-22 MeV)

Abstract

It has been long known that patients treated with ionizing radiation carry a risk of developing a second cancer in their lifetimes. Factors that contribute to the restate of cancer (or may be called second cancer) includes improved cancer survival rate by using high radiations as well as emerging treatment modalities. These modalities such as electron beam therapy or external beam radiation therapy. They can potentially elevate secondary exposures to healthy tissues distant from the target volume. The standard Linear-Quadratic (LQ) survival model for electron beam radiotherapy is reviewed with particular emphasis on studying how different schedules of radiation treatment planning may be affected by different tumour repopulation kinetics. The LQ model is further examined in the context of tumour control probability (TCP) models. A high energy electron (6-22) MeV through linear accelerator is used to strike the target in cancer treatment. In general, radiotherapy has different energy of electron used for cancer treatment which depends on the various factors such as general patient health and history and the stage of the cancer. The crucial problem in the radiotherapy in cancer treatment is that electron beam did not know the difference between healthy and cancerous cell. External beam radiotherapy is used to deliver the radiations to the organ. In this study, beast organ selected as a target volume. The breast organs include surrounding tissues/OARs such as brain, lungs, liver, breast, thyroid and colon. Thus, the purpose of this study is to analyze and calculate the effect of high energy electrons on these surrounding tissues of breast. Thus mathematical & biological model, (LQM) is used as a tool to calculate the Biological Effective Dose (BED) with dose per fraction 1.8 for nearer to the pelvic. Moreover, the aim of this study is to provide an understanding of the principles and methods related to scattered doses (electron beam) in surrounding organs to check and optimize the dose plan in radiation therapy by summarizing a large collection of dosimetry and clinical studies