What modality uses x-rays, gamma rays, and particulate radiation to destroy cancer cells?

• A. Medical oncology
• B. Immunotherapy
• C. Radiation oncology
• D. Surgery

Answer: (C)

The concept being tested is that this treatment approach uses ionizing radiation to destroy cancer cells. Radiation therapy relies on x-rays, gamma rays, and particulate radiation to damage the DNA of tumor cells, leading to their death. It can be delivered from outside the body (external beam) or from inside the body (brachytherapy) and is planned to maximize tumor kill while sparing normal tissue through careful dosing and fractionation. That’s why radiation oncology is the best answer: it is the medical specialty defined by using these forms of radiation to treat cancer.

Other modalities don’t rely on radiation: medical oncology uses systemic drugs to kill cancer cells throughout the body; immunotherapy enhances the immune system’s ability to attack cancer; surgery physically removes tumor tissue.