Scientists and doctors, out of happenstance, discovered that radiation regressed or slowed some tumors according to some studies on record. They were ignorant of the specific reasons why, but the first radiation oncologists cured, from historical record, the first cancer case in 1898.

They were mostly cures of superficial cancers and the reoccurrence of tumors in treated patients were high due to the unrefined nature of the radiation application methods and the massive doses or radiation given.

Through the late thirties until after World War II some hardware advances were made to help propel charged particles through a vacuum tunnel called a linac, or linear accelerator. This was used to make a more concentrated penetrable means to send x-rays to cancerous areas deeper in the body while not affecting the skin as much.

Two scientists from Stanford, Dr. Henry Kaplan and Edward Ginzton, worked together to bring this up to a standard where it could be used in a clinical setting. By 1960 the work done by these two researchers spawned the first publically launched rotational radiotherapy linac called the "Clinac 6."

By the time the Clinac 6 came out in the early 1960s, a radiation oncologist had a high powered x-ray delivery machine system. However, the accuracy of locating the tumor and directing the charged particles still had a ways to go.

Modern Hardware Advances

The biggest hurdle to develop better radiation therapy hardware was to avoid affecting the healthy cells as much as possible. The tumor had to be targeted better and the charged particles needed to basically stay in line of the tumor's shape.

The computer age helped enable a three dimensional x-ray look at a tumor. Coupled with the mapping means of new internal scanning technology and radiotherapy, the Intensity-modulated radiation therapy or IMRT machine came to fruition.

The IMRT uses the mapping information from what is called Computed Tomography (CT) scans. This produces a 3-D image of the tumor. The image data is then fed into the x-ray beam linac system to target the contours of the tumor.

A recent specific form of IMRT is the TomoTherapy system, which is a commercial patented process that uses the CT guided IMRT technology which can direct the radiation source spiraling around the patient. This makes the 3-D contours of a tumor more easily traced by the beam from the linac.

TomoTherapy is quite new, having just started its first clinical use in 2003.

The latest advancement in scanning technology within the radiation therapy world is a system called Image Guided Radiation Treatment. The IGRT machine is a delivery system that uses dynamic CT images of the body that actually compensates for any movement the tumor may have.

The big problem with scanning and targeting tumors is that the target moves within the body. The IGRT technology compensates for degrees of movement to make targeting the tumor much more accurate. This is the bleeding edge of radiation therapy today.