Definition of Interstitial radiation therapy

Interstitial radiation therapy: Radiation treatment given by placing radioactive material directly into the target, often a tumor.

For example, in treating prostate cancer, radioactive seeds are implanted in the prostate gland. The seeds might be titanium-encased pellets containing the radioisotope iodine-125.

Interstitial radiation therapy is also called seed implantation or brachytherapy (brachys being Greek for short).

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=9827
Last Editorial Review: 6/14/2012