Radiation Oncology generally refers to the treatment of cancers using radiation. Worldwide, most radiation treatment of cancer is performed using x-rays or electrons (small sub-atomic particles). Treatment can also involve placing small amounts of material which radiate x-rays or electrons or other particles directly into the tumorous areas.

Utilizing new technologies, it is now possible to deliver high doses of radiation to a tumor while minimizing healthy tissue exposure.  This method is called Intensity Modulated Radiation Therapy or IMRT.

In IMRT, the beam intensity (strength) is varied across the treatment field.  Rather than being treated with a single, large, uniform beam, the patient is treated with many very small beams; each can have a different intensity.  By cross firing the tumor with these beams, the physician delivers a relatively uniform radiation dose to the tumor, but protects sensitive, surrounding tissue from high-dose radiation. 

When the tumor is not well separated from the surrounding organs at risk, such as what occurs when a tumor wraps itself around an organ, there may be no combination of uniform intensity beams that will safely separate the tumor from the healthy organ.  In such instances, IMRT allows more intense treatment of the tumor, while limiting the radiation dose to adjacent healthy tissue.

The Department of Radiation Oncology here at UCI Medical Center was one of the first places in the world to treat using the NOMOS IMRT system and the first in Southern California.  Since 1997, the department has treated over 185 patients with various tumor sites.