High dose rate (HDR) radiation therapy is a form of brachytherapy. Brachytherapy is an internal radiotherapy cancer treatment approach that attacks malignant tumors by placing a radioactive source within (intracavitary) or very near (interstitial) cancerous tissue. The purpose of using brachytherapy is to deliver a concentrated dose of radiation more precisely to the tumor than can EBRT.

With HDR, a catheter or a cylinder is precisely positioned in the body, and then radioactive seeds are placed inside the device. This places radiation inside (intracavitary) or very near (interstitial) the area to be treated. HDR allows doses of radiation equivalent to those delivered via EBRT in just a few outpatient procedures. It is often done on an outpatient basis, and is appropriate for a number of treatment sites, including gynecological cancers.

HDR can be the only therapy used in a patient’s treatment or it can be used in conjunction with external beam radiation therapy (EBRT) and other treatment therapies.

For more information about High Dose Rate from Varian Medical Systems, go to http://www.varian.com/us/oncology/brachytherapy/hdr_brachytherapy.html.

For more information, please view the following websites:

• Cancer Net at http://www.cancer.net/portal/site/patient
• National Cancer Institute (NCI) at http://www.cancer.gov/
• American Cancer Society at http://www.cancer.org/docroot/home/index.asp

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