What is VMAT?
Volumetric modulated arc therapy (VMAT) is a modern radiation therapy technique that works by delivering a continuous beam of radiation in the shape of an arc around your body. As the machine (called a linac) moves, it changes the beam shape and treatment dose automatically.
VMAT is very accurate and maximizes the radiation dose to the tumour while minimizing the overall dose to surrounding healthy tissue. VMAT delivers radiation in a similar fashion to IMRT and both are excellent at sparing healthy tissues, however, VMAT treatment can be delivered much quicker, often in as little as 10 minutes.
As VMAT greatly reduces the risk of radiation being delivered to healthy tissues surrounding the tumor, we frequently use it to treat cancers that are next to important organs. For example, VMAT is often used to treat localized prostate cancers and the risk of side effects, such as bowel problems and sexual dysfunction, are greatly reduced when compared to conventional radiation therapy.
How does VMAT work?
Before VMAT treatment, you’ll need to undergo some planning scans. These create a detailed view of your cancer and surrounding organs to establish the exact shape, size and location of your tumor. This is typically a CT scan but may also include an MRI. Your care team will use these scans and advanced computer technology to determine your personalized treatment plan.
At the start of each session, you’ll lie on the treatment table and your radiation therapist will help you into the right position. It’s important that you are in the correct position for treatment and remain still throughout. Many of our centers offer surface-guided radiation therapy which has eliminated the need for body molds or tattoos by using cameras to track your position during set-up and throughout treatment. Read more about surface-guided radiation therapy.
When you’re ready, treatment will begin. Radiation will be delivered as the linac moves around you. During treatment, the machine continuously adapts the shape and intensity of the radiation beams. Although the tumor is targeted with a very high dose of radiation, the procedure itself is entirely is painless. Once your treatment course is complete, you’ll have a number of follow-up appointments so we can monitor your progress.
The number of treatment sessions you’ll need will vary depending on the size of your tumor, your radiation oncologist will discuss this with you in more detail. We understand that fitting appointments around your daily activities can be difficult, so we’ll do our best to accommodate your schedule. Our convenient treatment locations mean you can access world-class cancer care close to home, so you can focus on your life and doing the things you love, while we focus on treating your cancer.