Below is a list of commonly used words when discussing radiation therapy. The following definitions may help you as you discuss your treatment options with your doctor.
Adaptive Radiotherapy (ART)
Changing a treatment plan between (or even within) treatment fractions, based on feedback received from TomoTherapy Hi•Art Treatment System measurements and processes, ensuring that patients receive the most accurate treatment based on up-to-date information.
Each beam is divided into many smaller, narrow "beamlets." This means that instead radiation being delivered through one beam, it is delivered through hundreds of smaller, more precise beams during a single rotation of TomoTherapy treatments. It's simple really; more angles and more beams mean more precise treatment.
Conformal Avoidance Radiotherapy (CA)
A form of IMRT (Intensity-Modulated Radiotherapy) used when the tumor boundary cannot be easily defined. Rather than trying to map the precise area to be treated, doctors can map out surrounding healthy tissue and organs that must be avoided. This "everything but" strategy is central idea behind TomoTherapy treatments.
The goal of conformal therapy is to deliver a high dose to a volume that closely conforms to the shape of the patient's tumor volume. It requires the ability to accurately identify both the exact shape and location of the tumor so as to distribute the dose as close as possible to the margin around the target.
Only the TomoTherapy Hi•Art Treatment System has built in true CT imaging technology. TomoTherapy uses this built in imaging technology to take CTrueTM images before each treatment session to verify treatment. It allows doctors to adapt the treatment plan depending on any changes in the size, shape or location of the tumor, as well as account for other normal bodily changes that occur naturally from day to day. These CTrueTM images also mean that your treatment is based on an actual picture of your current anatomy, something that only TomoTherapy offers.
The built in Delivery Modification capability of TomoTherapy adjusts the delivery pattern to compensate for any changes in the patient's position or the location of the tumor between each rotation of TomoTherapy. Instead of physically repositioning the patient (which can be a time-consuming and error-prone procedure), delivery modification can recalculate the delivery pattern based on the patient's displacement.
TomoTherapy uses a signal measured at end of each rotation to compute and verify any things during treatment. This information is used to monitor the treatment delivery and shut down the unit if delivery errors are detected. Again, this ensures that patients receive the most accurate and precise treatment, sparing surrounding healthy tissue and organs.
Image-Guided Radiation Therapy (IGRT)
IGRT is radiation treatment guided by imaging technology such as CT scans, MRI's, or PET scans. Doctors use the CTrueTM images to verify the patient's position, anatomy and tumor site at the time of treatment, helping ensure the accuracy of each treatment procedure. TomoTherapy is the only technology that allows doctors to verify treatments with pictures of the patients current anatomy.
A method for positioning the patient for each TomoTherapy treatment. The doctor takes a CTrueTM image of the patient and then superimposes that image over a reference image. The planning image can then be manually or automatically adjusted to get the best match.
Intensity-Modulated Radiotherapy (IMRT)
One of the most important recent advances in radiation treatment, IMRT involves changing the size, shape, and intensity of the radiation beam to conform to the size, shape, and location of the patient's tumor. The TomoTherapy Hi•Art Treatment System uses patented technology to adapt the intensity of the radiation beam so that it precisely conforms to the shape of the tumor.
In radiation therapy, a prescription usually defines the dose (in Gy) or radiation to be directed to the tumor.
Also called radiation therapy, radiotherapy is the treatment of cancer and other diseases with ionizing radiation, with the aim to eliminate cancer cells. Although radiation damages both cancer cells and normal cells, normal cells can repair themselves more quickly, while the cancer cells sustain more and more damage with each treatment.