Abstract
Adjuvant radiotherapy in breast cancer using proton bundles is not yet part of any recommendations despite undisputable dosimetric benefits, including mainly lower doses for the heart, the lungs and the second-sided breast. The reason is the lack of clinical data on proton radiotherapy in breast cancer, which would confirm its theoretical advantage in practice.
The results of studies evaluating cardiovascular morbidity after irradiation of the left side of the chest are not unambiguous; however, cardiac doses should be monitored and reduced even when performing photon radiotherapy. Modern techniques that allow this to happen include the technique of breath holding or irradiating only tumor beds in a certain group of patients, or by placing a patient on the abdomen using a so-called breast board.
Questions about the clinical benefit of proton RT in breast cancer should be answered by ongoing clinical trials.