How does radiation therapy destroy cancer cells?
During radiation therapy, tumors are exposed to radiation, either from an external or implanted source. Cancer cells treated with radiation are unable to reproduce because their DNA is damaged. When these cells die, they are absorbed harmlessly by the body.
When and why is radiation used to treat cancer?
Radiation therapy may be used to slow tumor growth, to prevent cancer from spreading or recurring, or to relieve any pain or other symptoms caused by the disease. Sometimes it is administered to a patient before surgery so less tissue needs to be removed and sometimes it is given post-operatively to destroy any cancerous cells that remain. Certain cancers, such as prostate and larynx cancer, can be treated with radiation alone.
Who are radiation oncologists?
Radiation oncologists are physicians who have been specially trained to treat cancer using radiation therapy. They work together with other members of the treatment team, which may include general practitioners, surgeons and medical oncologists, to help patients through this difficult time.
What kind of radiation therapy do I need?
Radiation may be delivered from an external source during external beam radiation therapy, also known as EBT. It also may be received from an implant in internal radiation therapy, or brachytherapy. In both cases, the goal is to target tumors with sufficient radiation while protecting healthy tissue from damage. The kind and duration of radiation therapy recommended for a patient depends on a number of factors, including the type and extent of the tumor being treated.
Types of cancer that are frequently treated with radiation therapy include:
Breast cancer
Radiation may be used on part of the breast, the entire breast or areas near the breast such as lymph nodes. Treatment often follows a mastectomy or lumpectomy procedure and chemotherapy to ensure eradication of cancer cells.
Brain tumors
Radiation may eliminate the need for invasive surgery in the brain.
Prostate cancer
Radiation allows for precise treatment without affecting nearby organs such as the bladder and rectum. Treatment may also involve hormone therapy. Advanced treatment modalities such as intensity-modulated radiation therapy, or IMRT, and intraoperative radioactive seed implants, or brachytherapy, are typically used.
Colorectal cancer
Radiation is given alongside chemotherapy before or after surgery.
Head and neck cancer
Radiation and chemotherapy are often used with or without surgery. Most patients undergo IMRT to spare critical normal tissues.
Lung cancer
Radiation and chemotherapy are often employed to treat small cell lung cancer and may be combined with surgery for non-small cell lung cancer.