Nearly two-thirds of all cancer patients receive ionizing radiation therapy to treat their disease. During this therapy, high-energy beams are aimed at cancer cells to destroy them by permanently damaging their underlying genetic material. While these high-energy beams are targeted to the tumor site as precisely as possible, they often inadvertently injure healthy tissues that surround a tumor site. As a result, radiologists have been limited in the doses of radiation that they can use to effectively destroy cancer.
What is IMRT?
A new and revolutionary advance in radiation treatment called Intensity Modulated Radiation Therapy, or IMRT, may offer a solution to this problem. A vast improvement over standard radiation, IMRT allows the delivery of extremely precise doses of radiation that destroy cancer cells while minimizing harm to surrounding normal and healthy tissues.
IMRT administers a radiation field that consists of several small beams of varying intensities that pass through normal tissue without doing damage, but converge to give a precise dose of radiation at the tumor site. In this way, IMRT limits adverse side effects from radiation while increasing the intensity of doses that can be given to effectively destroy cancer cells. Side effects from radiation treatment can include injuries to nerves or brain tissue, the salivary gland, jaw bone, or spinal cord, and the bowel or urinary tract.
How does the IMRT device function?
Physicians at Princeton BMC use an advanced type of IMRT manufactured by Varian Medical Systems that is fitted with a multileaf collimeter - a device with a series of computer controlled mobile apertures that subdivide radiation beams into many "beamlets" aimed in various directions, providing varying intensities of radiation. This type of IMRT also uses a dynamic delivery system, or a "sliding windows" technique that further optimizes radiation delivery by improving its accuracy to specifically target areas in a tumor.
Because it shapes the radiation dose three-dimensionally based on tumor shape and thickness, IMRT allows physicians to deliver higher doses of radiation to selected areas of a tumor - denser portions of a tumor are treated with higher doses, while less dense areas receive lower doses.
IMRT and Inverse Treatment Planning
IMRT is combined with a process called inverse treatment planning to determine the best way to treat a patient. It relies on CT (computed tomography) and MRI (magnetic resonance imaging) data from patients that is processed and analyzed by a complex computer system to produce the ideal radiation dose distribution for that patient.
Prior to the innovation of such computer systems, the process of determining how radiation should be delivered was less precise and much more labor intensive and time consuming since it required technicians to manually set and evaluate equipment after each treatment.
IMRT is a sophisticated technology that requires highly trained personnel with considerable experience using it to treat cancer patients.
Once your CT-Simulation is completed, the team will begin work on your IMRT plan. This normally takes 7-10 working days after all the needed information is gathered.
For more information on Radiation Oncology at Princeton BMC please call 1-877-222-7847 or e-mail us!