About IMRT (Intensity Modulated Radiation Therapy)
How Does Radiation Therapy Work?
All cells, cancerous and healthy, grow and divide. But cancer cells grow and divide more rapidly than many of the normal cells around them. Radiation therapy uses special equipment to deliver high doses of radiation to cancerous tumors, killing or damaging them so they cannot grow, multiply, or spread. It works by breaking a strand of the DNA molecule inside the cancer cell, which prevents the cell from growing and dividing. Although some normal cells may be affected by radiation, most recover fully from the effects of the treatment.
What is IMRT?
IMRT (intensity-modulated radiation therapy) is a relatively new technique to improve external delivery of radiation therapy by a linear accelerator. Intensity modulated radiation therapy (IMRT) is a method that allows the strength of the beam to be changed to lessen damage to normal body tissues. This technique allows for the doctor to change the intensity of the radiation within each beam to safely increase the amount of radiation delivered to the prostate. This technique can be further enhanced by adding visualization of the prostate anatomy before each daily treatment, called Image Guided Radiation Therapy or IGRT.
Unlike chemotherapy, which exposes the entire body to cancer-fighting chemicals, IMRT/IGRT is a state-of-the-art local treatment that only affects the part of the body being treated.
How Does IMRT Work?
Instead of maintaining a uniform radiation beam as used in conventional or 3- dimensional radiation therapy, IMRT uses devices within the linear accelerator to divide the radiation beam into multiple smaller beams called beamlets that can have different intensities (modulated) within the area being treated. This allows more precise delivery of radiation doses to the tissues within the target area, allowing increased doses to the prostate while relatively sparing the surrounding bladder and rectum. This is important as several recent medical studies have suggested that higher prostate doses are associated with increased curability.
Understanding Radiation Therapy Guide for Patients and Families
This booklet has been created to help you understand your disease and how the treatment team at the Prostate Cancer Center collaborates with your urologist in curing your cancer. Additionally, the booklet is designed to answer your questions and those of your loved ones about the treatment of prostate cancer with radiation therapy.