Volumetric Modulated Arc Therapy (VMAT)
What Is VMAT ?
VMAT (Volumetric Modulated Arc Therapy) is a type of intensity-modulated radiation therapy (IMRT), but it works much faster. Instead of delivering radiation from multiple fixed angles, VMAT rotates around the patient in an arc while continuously adjusting the beam shape, dose rate, and angle. This allows for highly conformal treatment in a shorter time.
How VMAT Works
A full 3D image of the tumor and surrounding tissues is created.
The machine delivers radiation while rotating 360° around the patient.
The dose is continuously adjusted to match the tumor’s shape and depth.
Each session is fast—usually just a few minutes.
Frequently Asked Questions
Volumetric modulated arc therapy (VMAT) delivers the maximum radiation dose to the cancerous tumor without exposing healthy tissue to harmful radiation levels. As the machine rotates around you, it continually adjusts the shape and strength of the radiation beams directed toward the tumor. High doses of radiation reach the tumor and destroy cancer cell DNA, causing these cells to die.
Treatment planning is an essential part of VMAT. As part of your diagnosis, your cancer care team generates 3D images (usually using CT scans or MRI and/or PET scans) of your body. They use these images to identify the tumor and nearby organs that need to be protected from the radiation. They determine the radiation dose required to destroy the tumor.
During a planning or mapping session called simulation, or “sim,” your care team will position you on a treatment couch. They’ll line you up in relation to the LINAC machine so that the radiation will strike your tumor at the precise location once it’s time for your treatment session. You may receive:
Treatment sessions take about 20 minutes. Most of that time will involve the radiation therapist positioning you for treatment. It takes approximately two minutes for the LINAC machine to deliver the radiation.
Depending on your diagnosis, you may need daily VMAT treatment sessions for several weeks. Ask your oncologist about your treatment schedule.
You’ll be able to leave the treatment facility that same day and resume your regular schedule.
When should I see my healthcare provider?
You’ll need follow-up appointments to check on your progress after VMAT. Keep all scheduled appointments. Come prepared to ask questions about your treatment response and report any symptoms or side effects you’re experiencing.