The present challenge in the treatment of tumors is to reduce the number of patients that still die as a result of primary tumors. Today, the percentage of such deaths remains high at 30%, even when all the common therapeutic methods, namely surgery, radiotherapy, and chemotherapy, are applied. In order to reduce this percentage, new types of radiation sources with a higher linear energy transfer have been intro- duced, such as neutrons and pions. Fractionation patterns have been modified and radiosensitizers have been applied to in- crease biological efficiency. Studies of the combined...