What type of radiation treatment is given internally?

The type of radiation treatment that is given internally is radioisotope radiation. This method involves the use of radioactive substances that are introduced into the body to target and treat cancerous tissues. Radioisotopes can be administered via injections or orally, allowing them to localize within specific organs or tumors, delivering targeted radiation therapy directly to the affected area.

In contrast, proton beam radiation and CyberKnife radiation are forms of external beam radiation therapy. Proton beam therapy involves directing protons at the tumor from outside the body, while CyberKnife uses a robotic system to deliver highly focused radiation from multiple angles, also from an external position. Total body radiation encompasses the irradiation of the entire body, typically done externally, and is often used in preparation for procedures like bone marrow transplants. Therefore, radioisotope radiation is distinct in its internal application, making it the correct answer.