Orthovoltage

Orthovoltage X-rays are sometimes termed "deep" X-rays (DXR). When used to treat patients, radiation oncologists find that they penetrate to a useful depth of about 4–6 cm. That makes them good for treating skin, superficial tissues, and ribs, but not for deeper structures such as lungs or pelvic organs. As with newer technology, we are able to produce X-rays of much higher energy, the penetration of orthovoltage X-rays is considered quite shallow.

The radiation from orthovoltage units is referred to as x-rays that are a lower energy than the radiation produced in a standard external beam radiation treatment from a linear accelerator or “linac.” The maximum dose is deposited at the skin surface and the radiation dose to the underlying tissue falls off rapidly. As a result the maximum side effects are seen on the skin surface.

Orthovoltage units are best suited for treatment of very small, very superficial (shallow, not invading deeper layers) skin cancers.