The field of radiation therapy is, in its most basic definition, the field of treating cancers by using ionized subatomic particle radiation aimed at tumors to control and disable the growth of malignant cells. The use of radiation for cancer control can be used for curative, palliative (non-curable symptomatic relief) and in combination with other treatments (like chemo).

The use of radiation in the field of oncology creates a new subset practice called radiation oncology (strangely enough). Radiation oncology has its own specific tools and means of delivering radiation into the patient's body.

The use of radiation to treat cancer has been around for nearly 100 years. The beginnings of this practice were spotty at best, and often left the patient with secondary cancers from the treatment itself. It was quite a dicey measure at the time.

However, the next 80 years computer software imaging such as the MRI and the digital linear accelerator have made mapping and targeting the tumor much more safe and accurate.

Modern Radiation Oncology Hardware

The linear accelerator (device that shoots the subatomic beam at the tumor) is the main tool at a clinician's disposal. The device made it easy to apply the particles in a targeted direction, but the biggest hurdle to develop better radiation application was to avoid harming healthy cells as much as possible. The particle beam had to be refined delicately enough to stay within the boundary of the tumor's body, staying within the lines so to speak.

The computer age advanced radiation oncology's scope by introducing new software to help 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 in the radiation oncology field.

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, which just started it first clinical use in 2003.