Measurement of Therapeutic Proton Beam Using a Fiber-Optic Cerenkov Radiation Sensor

Tumor therapy using the high-energy radiation has evolved over the decades as typical non-invasive treatment method due to its advantage compared with surgery. But, the radiotherapy can damage or destroy normal cells as well as destroying tumor cells and cause side effects of treatment. Even though most side effects are temporary, these effects can be extremely fatal for patient. Therefore, the exact measurement of the exposure dose of patient during radiation therapy is very important for patient safety. In the case of the conventional fiber-optic radiation sensor that consists of a scintillator for high-energy radiation dosimetry, additional correction is necessary due to the quenching effects of the scintillator. In this study, we measured the exposure dose of the high-energy proton beam without the scintillator by using the Cerenkov radiation that generated inside the plastic optical fiber. As a result of this study, we confirmed a Bragg peak of the proton beam without a scintillator. Also it was in good agreement with the result of the ionization chamber.