- How does radiation therapy work?
- What is radiation therapy used for?
- What are the types of radiation therapy?
- What adverse effects can occur with radiation therapy?
- Which cancers is radiation therapy used to treat?
- Phase of cell—A cell goes through 5 phases in its cycle of division—from resting to mitosis. Cells in the resting phase are less sensitive to radiation (and therefore less likely to be damaged) than cells that are actually dividing (in mitosis).
- Division rate of the cell—Rapidly dividing cells are more sensitive than slowly dividing cells.
- Oxygenation—Because oxygen is necessary to form the hydroxyl radical (which leads to cell destruction), highly oxygenated tissues are more sensitive to radiation therapy. This has been clearly demonstrated in cervical cancers and cancers of the head and neck. In fact, the presence of oxygen is so important that people who smoke, and therefore lower the oxygen level to their tumor, suffer from a 50% reduction in the ability of the radiation to kill the cancer.
|Orthovoltage||X-rays with 150-500 kilovolts (kV) of energy||
Superficial treatment scatter of radiation beam
|Superficial skin cancer|
|Megavoltage||X-rays and electrons with 1-18 million volts of energy||
Deeper penetration below skin level
|All tumors other than skin cancer|
- Interstitial radiation—The implant is placed directly into the tumor via catheters, seeds, or capsules. This is commonly used for prostate cancer.
- Intracavitary radiation—Commonly used for cervical cancer, the implant is placed in special applicators inside a body cavity.
- Intraluminal radiation—Commonly used for lung or esophageal cancer, the implant is placed in special applicators inside a body passage or lumen.
- Surface brachytherapy—The implant is placed in or against the tumor. This is commonly used for skin cancer or melanoma of the eye.
- Wash with lukewarm water and mild soap, and pat dry.
- Do not wear tight clothing over the area.
- Do not rub, scratch, or scrub the skin in the treated area.
- Avoid putting anything hot or cold on the treated area.
- Avoid exposing the radiated area to the sun during treatment.
- Ask your doctor to recommend a cleanser and moisturizer for your sensitive skin.
Evolution of cancer treatments: Radiation .American Cancer Societ website. Available at: http://www.cancer.org/cancer/cancerbasics/thehistoryofcancer/the-history-of-cancer-cancer-treatment-radiation. Updated June 12, 2014. Accessed May 27, 2015.
Hyperthermia in cancer treatment. National Cancer Institute website. Available at: hhttp://www.cancer.gov/about-cancer/treatment/types/surgery/hyperthermia-fact-sheet. Updated August 31, 2011. Accessed May 27, 2015.
Modalities of cancer therapy. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/hematology-and-oncology/principles-of-cancer-therapy/modalities-of-cancer-therapy. Updated July 2013. Accessed May 27, 2015.
Photodynamic therapy for cancer. National Cancer Institute website. Available at: http://www.cancer.gov/about-cancer/treatment/types/surgery/photodynamic-fact-sheet. Updated September 6, 2011. Accessed May 27, 2015.
Radiation therapy for cancer. National Cancer Institute website. Available at: http://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/radiation-fact-sheet. Updated June 30, 2010. Accessed May 27, 2015.
Understanding radiation therapy: A guide for patients and families. Amerian Cancer Society website. Available at: http://www.cancer.org/acs/groups/cid/documents/webcontent/003028-pdf.pdf. Accessed May 27, 2015.
- Reviewer: Mohei Abouzied, MD, FACP
- Review Date: 03/2015 -
- Update Date: 05/27/2015 -