The history of cancer radiation and treatment began in the 1890’s, where initial machines applied radium, or low energy X-rays.  Technology progressed, and by the 1930’s million-volt machines were employed.  Cobalt machines became available after World War II, and by the 1960’s and 1970’s higher energy linear accelerators were utilized. Once CT scans and computers identified targets for radiation treatment in the 1990’s, the beam could be conformed (or modified) for better accuracy, hitting the tumor while avoiding normal structures in three-dimensions, called 3D conformal therapy. Often five or six separate beams were involved in the process.

In the late 1990’s and early 2000’s, the beams could be further modified to hit the target more precisely using a technique called Intensity Modulated Radiation Therapy (IMRT).  Then, imaging devices were attached to the linear acceleratory to better ensure the target was setup accurately everyday, using a technique called Image Guided Radiation Therapy (IGRT). Often, as many as 7 or 9 beams provided even more sophisticated targeting.

Finally, the ultimate machine was designed and built using technology similar to a CT scanner.  Just as a CT scan provides extremely precise and detailed information about normal and abnormal anatomy, the TomoTherapy treatment device delivers radiation accurately to the target area while delivering little radiation to normal tissues.  It is able to do this because instead of delivering the radiation at only a few different directions, it delivers the radiation in a complete 360 degree arc while continuously modifying the shape and intensity of the radiation beam.

Since the device is designed around a CT scanner, it is able to do a CT scan each day before treatment delivery to verify target placement.  If the placement has changed, the radiation treatment can be modified to adapt to changes in the position of the tumor and changes in the patient’s anatomy (like weight loss) which is a technique called adaptive radiotherapy (ART).

Another innovation in modern cancer treatment is the use of highly targeted radiation to eradicate tumors with surgical precision, yet without the use of surgery (’bloodless’ surgery, or radiosurgery).  Radiosurgery devices (e.g. Gamma Knife) have been remarkably effective for treating benign and malignant tumors but are restricted to tumors of the brain and require that a frame be attached to the patient’s head for accuracy. The most revolutionary device for radiosurgery (The Cyberknife) does not require a frame and can be used to treat tumors anywhere in the body (referred to as frameless, extracranial radiosurgery).