Q: My 30-year-old sister was recently diagnosed with cancer. She was told that radiotherapy is an option. What is radiotherapy and how is it different from other treatment forms such as chemotherapy?
A: Radiotherapy is a type of cancer treatment that can cause the DNA of cancer cells to break and lead to cancer cell death. It uses an external form of high- energy rays equivalent to X-ray, or internal form of internal radiation using high-energy gamma rays. Although the surrounding normal cells can also be affected, they usually recover and function normally.