Intensity Modulated Radiation Therapy or IMRT is a type of 3D radiation. It allows physicians to determine the size and shape of the tumor by using high energy beams which are able to target the cancer cells directly. This type of radiation can be used to treat prostate cancer, tumors of the neck and head, as well as tumors located near the liver, spinal cord, brain, and kidneys just to name a few.
The IMRT uses hundreds of radiation rays which vary in intensity so that the tumor can be precisely radiated. The radiation that is used is varied throughout the process, so that the beams change multiple times throughout the therapy treatment. In this way, the radiation surrounds the non-cancerous tissues of the area, and instead of attacking both cancerous and health cells, it just targets the cancer cells. The high doses of radiation have been shown to more successfully treat the cancer by aggressively eliminating the unhealthy cells.
This form of radiation has been known to treat tumors which have previously been considered to be untreatable as they were located too close to essential organs and other critical body structures. In order to successfully complete the radiation process, image scans such as CT, MRI, or PET scans are taken in order to determine the location of the healthy tissues. Then the computer images are used as a guide so that the radiation can be beamed solely onto the cancer tissues.
The doctor is responsible for developing a plan for treatment as well as instructions on dosage. The treatment plan will be based on the size of the tumor as well as the location and shape of the tumor in the body. In the IMRT, the radiation equipment can be moved to different areas of the patient.
This is in order for the radiation rays to come from several angles thereby allowing for the tumor to be localized and treated directly. Localization is especially important when treating tumors in the neck and head as radiation can be very damaging to many areas in these locations such as the optic nerve, the spinal cord, the salivary glands, as well as several other areas.
In other areas such as the prostate, general radiation can potentially damage the bladder and the rectum. However, with the use of IMRT, it is less likely that this damage can occur. IMRT can also occur in different areas such as the pelvis, abdomen, as well as the chest. In the case of prostate cancer, gold beads may be placed within the prostate in order to track movement in the prostate so as to make sure that the radiation will precisely target the tumor in the prostate.
IMRT is typically treated over a series of treatments which occur between four and eight weeks. The exact number of treatments is affected by the location, size, the general health of the patient, as well as the type of cancer.