There is one substantial reason to indicate proton radiotherapy and that is RIHD (radiation induced heart disease). Heart disease caused by radiation is one of the most serious late effects of radiation. In the treatment of malignant lymphoma for which radiation has been recommended, experts therefore work to minimise radiation doses to the heart. Thanks to the proton beam, we are able to significantly reduce the risk of the occurrence of cardiac infarction, cardiac complaints, or the risk of development of pulmonary fibrosis.