IMRT (intensity modulated radiation therapy) is the most advanced approach to what is known as 3D conformal radiation. The ultra-precise IMRT technique has already been shown to improve outcomes and reduce toxicity in cancers of the prostate, head and neck. Currently ongoing studies are examining the use of IMRT for a wide variety of other cancers, including breast, brain and gynecologic.
IMRT uses computer-generated images based on a patient’s CT scan anatomy to plan and deliver more focused radiation than is possible with conventional therapy. With this capability, clinicians can exquisitely “paint” a precise radiation dose that conforms to the shape and depth of a tumor, while significantly reducing adverse effects on healthy tissues.
The preciseness of IMRT allows physicians to deliver substantially more cancer-killing radiation to tumors and, at the same time, to decrease potentially harmful doses to surrounding normal tissue. Clinical studies indicate that the higher doses delivered via IMRT improve local tumor control. Recent studies in prostate cancer have shown that IMRT improves the chance of remaining recurrence-free while simultaneously reducing the rate of certain normal tissue complications from 10 percent to 2 percent.
The precision of IMRT is achieved through the integration of a computerized medical linear accelerator (which produces the radiation beams) with advanced treatment planning software and specialized blocking devices that “sculpt” the radiation beam.<