The goal of this paper is to deal with the radiological aspects of breast cancer radiotherapy. Due to the fact that breast cancer is one of the most frequent malignant diseases in today's world, there are many methods and approaches that have the goal of tumor eradication and radiotherapy is exactly one of them. Radiotherapy is actually a very complicated method that consists of many smaller tasks that need to be precisely done in order for the therapy to be successful. The making of a radiotherapy plan includes CT planning, charting the organs that are at risk, marking the target volume that leads to creation of an isodose plan. Radiotherapy is performed by a team consisting of specialists of radiotherapy and oncology, physicists and a radiological technician, so in order for the radiotherapy itself to be successful everyone has to do their job exemplary and strive to contribute as much as they can to the planned therapy.