Varian 21EX Linear Accelerator

With the Varian 21EX linear accelerator (LINAC), external beam radiation therapy is delivered using high-energy x-ray and electron beams that are custom shaped to treat the tumor or “target volume” and spare the healthy normal tissue. Our computer-controlled accelerators are equipped with differing energies and devices, making them capable of delivering specialized cancer treatments. A recent procedure, intensity modulated radiotherapy (IMRT), improves upon the precision of treatment.

How Does IMRT Work?
Intensity Modulated Radiation Therapy (IMRT) is a new and more precise way of administering external beam radiation therapy to treat specific types of tumors. Using a Varian 21EX Linear Accelerator machine, radiation is precisely delivered by changing the intensity of the beam as the treatment is delivered. The radiation is focused more closely on the tumor cells, sparing much of the surrounding healthy tissue and leaving tumors unable to divide and spread.

Not everyone is a candidate for IMRT. Some of the more common disease sites that may be appropriate are prostate, brain, head and neck, and gastrointestinal. Individual situations will differ; ask your radiation oncologist if IMRT is appropriate for you.

Other Techniques

Brachytherapy for Prostate Implants
Brachytherapy treats cancer using precisely placed radioactive implants in tumors. The implants can be permanent or temporary, but the goal is the same: conform the radiation dose to the size and shape of the target and limit side effects by sparing the surrounding healthy anatomy.

Brachytherapy has been highly successful in prostate, gynecological, breast, and several other types of cancer.

HDR (high-dose-rate brachytherapy)
HDR is a newer advance in radiation treatment allowing a small radioactive source to be temporarily placed inside numerous types of tumors. Using a computer, the position and timing of source placement can be precisely controlled, allowing the physician to shape the radiation dose field. Because of the high-dose-rate characteristics, brachytherapy treatments can often be delivered on an outpatient basis or with a minimal hospital stay.