Intensity-modulated radiation therapy, or IMRT, is an advanced type of external beam radiation cancer treatment that focuses the radiation on the tumor while sparing the surrounding healthy tissue thereby reducing side effects of treatment.

How IMRT Works

In IMRT treatment, a complex pattern of small radiation beams of varying intensity is delivered. These beams are constantly changing throughout the treatment to conform the radiation to the tumor and spare healthy tissue.

IMRT is the standard way radiation therapy is delivered for some of the most common cancers including cancers of the prostate and lung.

VMAT Advanced IMRT

Volumetric arc therapy, or VMAT, is an advanced form of intensity-modulated radiation therapy (IMRT) that speeds up the treatment by delivering the radiation in a series of arcs around the body instead of from fixed angles.

By delivering the radiation in arcs, the radiation conforms more closely to the tumor.

VMAT treatment usually takes less than two minutes — oftentimes shorter than IMRT. This makes it easier for patients to lie still, which improves treatment accuracy and convenience. 

Types of Tumors IMRT Treats

Because most tumors are surrounded by healthy tissue, IMRT can be used on any part of the body to treat primary or metastatic tumors of any size and shape. IMRT is the standard technique used to treat many cancers such as prostate, lung, head and neck, rectal and others.

IMRT Side Effects

Because the radiation better avoids healthy tissue, IMRT side effects are usually minimal. IMRT is usually an outpatient treatment. After treatment, you can resume your regular daily routine. Your care team will give you any necessary instructions.

Make an Appointment

To make an appointment at UM Greenebaum Comprehensive Cancer Center in Baltimore, call 410-328-6080. Or, contact one of our other four radiation oncology locations in Central and Eastern Maryland.