High Energy X-Rays
Physics: AQA A Level, topic 10.6.4
High Energy X-Rays
Radiotherapy is effective against cancer because cancer cells reproduce rapidly and, consequently, are more sensitive to radiation.
Radiotherapy
- The central problem in radiotherapy is to make the dose for cancer cells as high as possible while limiting the dose for normal cells.
- The ratio of abnormal cells killed to normal cells killed is called the therapeutic ratio, and all radiotherapy techniques are designed to enhance this ratio.
Concentrating radiation
- Radiation can be concentrated in cancerous tissue by a number of techniques.
- One technique is to have a narrow beam of radiation is passed through the patient from a variety of directions with a common crossing point in the tumour.
- This concentrates the dose in the tumour while spreading it out over a large volume of normal tissue.
Test yourself on High Energy X-Rays
Which of these statements are true about high energy X-rays?
Why is it important to enhance the therapeutic ratio?