Radiology Practice Test

What type of radiation is primarily used in radiotherapy treatments?

1. X-rays

2. Ultrasound waves

3. Magnetic fields

4. Radio waves

The correct answer is: X-rays

Radiotherapy primarily utilizes X-rays because they are highly effective for targeting and destroying cancer cells. X-rays have sufficient energy to penetrate tissues, allowing them to focus on tumors while sparing surrounding healthy cells to a certain extent. This strategic application is crucial in treating various forms of cancer, as it helps to maximize the damage to malignant cells while minimizing adverse effects on normal tissues. The other options present alternatives that are not suitable for radiotherapy: ultrasound waves are primarily used for imaging and therapeutic purposes unrelated to cancer treatment; magnetic fields are utilized in magnetic resonance imaging (MRI) and certain therapies but do not have the destructive capabilities needed for cancer; radio waves are mainly used in communication technologies and not for direct treatment of tumors. Thus, X-rays stand out as the primary modality used in cancer radiotherapy.