Proton beam radiation is a type of radiation treatment that utilizes a proton beam to target the tumor. The precise delivery of the proton beam allows for the targeted destruction of tumor cells, while sparing healthy tissues and cells surrounding the tumor. Proton beam radiation is an example of external beam radiation and is a treatment option for sarcomas. Other examples of external radiation therapy include MRI linear accelerator and stereotactic body radiation therapy. In contrast, internal radiation uses a radioactive source near the cancer site and examples of internal radiation include brachytherapy, intraoperative radiation therapy, and stereotactic radiosurgery. Overall, the goal of radiation is to shrink and kill the tumor and malignant (cancerous) cells.