How Does Tomotherapy Work?

The Tomo^® Process combines treatment planning, CT image-guided patient positioning, and treatment delivery into one integrated system:

• Treatment Planning
  Before beginning TomoTherapy treatment, the physician uses three-dimensional images and special software to define the precise contours for each tumor. The physician also decides how much radiation the tumor should receive, as well as acceptable levels for surrounding structures. Then the TomoTherapy Hi•Art Planning Station calculates the appropriate pattern, position, and intensity of the radiation to be delivered.
• CT Image-Guided Patient Positioning
  Precise patient positioning is crucial for effective radiation treatment. With the TomoTherapy Hi•Art System^®, physicians can take a special CT scan, called a TomoImage^®, just before each treatment to verify the tumor's location and adjust the patient's position, if necessary. This is extremely useful since a patient's position may change slightly from session to session and certain types of tumors, such as prostate cancers, can change shape or shift from day to day. With the TomoTherapy Hi•Art System®, physicians can make sure that the radiation is directed precisely from one session to the next.
• Radiation Delivery
  TomoTherapy combines intensity modulated radiation therapy (IMRT) with a spiral delivery pattern. Photon radiation is produced by a linear accelerator (or linac), which rotates multiple times around the patient. The linac moves in association with a device called a multileaf collimator, or MLC. The computer-controlled MLC has two sets of interlaced leaves that modulate radiation beam while the patient, located on the treatment couch, moves slowly through the center of the gantry ring.