Radiation therapists at the University of Wisconsin Carbone Cancer Center offer tomotherapy among the treatment options for cancer patients.
Tomotherapy, the first technology of its kind, provides 3-D imaging of a tumor immediately prior to delivering radiation. With cancer patients lying on a platform, the machine takes an image of a tumor to verify its size, shape and location. Minutes later, it delivers a halo of radiation to the tumor in a spiral pattern around the patient, while minimizing contact with healthy tissue and avoiding the complications so often associated with standard radiation treatment.
Tomotherapy was discovered, developed and patented by UWCCC researchers, who first used it to treat patients in 2003. The tomotherapy machine combines two devices into one that seamlessly detects and defines cancer tumors, then delivers appropriate doses of radiation.
Each patient session includes multiple steps. First, a computed tomography (CT) image is taken of the patient who is lying on the tomotherapy machine's table. The result is a 3-dimensional image of the person and the tumor to be treated.
Next, technicians use the CT information to define the targeted tumor and determine the intensity of radiation - a method known as Intensity Modulated Radiation Therapy (IMRT). While IMRT isn't new, a critical innovation within the tomotherapy machine means that radiation is delivered via a linear accelerator, or Linac. The Linac moves along a circular path in a part of the machine that looks like a hoop. Moving the patient through this revolving hoop helps create 72 strategic points along a spiral from which to direct radiation to the tumor.
An important distinction between tomotherapy and other radiation treatments is that past methods exposed much larger areas of the body to higher levels of radiation distributed from fewer angles. Tomotherapy, with its ability to deliver lower doses from many different angles, affects very limited areas of healthy tissue and results in fewer side effects.