MRI-Guided Linear Accelerator

MRI-based imaging on a linear accelerator offers superior high-definition image quality, especially for some soft tissue cancers, as compared to traditional linear accelerators which use x-ray-based imaging to visualize the target area and adjacent anatomy for treatment setup and delivery.

The MRI image will allow your doctor to target the tumor with increased accuracy and precision with the ultimate goals of reducing the amount of radiation exposure to surrounding organs and reducing potential side effects.

Seeing is Adapting. Tumors and organs move. The MRI-LINAC can adapt the radiation treatment plan based on movement of the tumor or your organs, and also track the motion of the tumor.

When you breathe, swallow or digest food, your internal organs move and even the smallest movement can affect the position of a tumor, which makes accurate targeting of radiation therapy difficult.

The MRI-LINAC uses continuous MRI, capturing multiple images every second, to see the soft tissue and organs moving and then to compensate for these movements during treatment. It also includes advanced software that allows your doctor and treatment team to adapt your radiation treatment plan based on what they see each day. This level of personalization of radiation therapy has not been previously possible.

Treatment on the MRI-LINAC is a non-invasive procedure and most patients can return to their normal routine after treatment.

The machine will make sounds and you will lie still for the duration of your treatment, but you will not feel anything from the treatment beams.

Each patient’s treatment plan will be different depending on the size, type and location of your tumor, your general health and any other treatments you may be receiving.

First you will have a consultation with one of our radiation oncologists who specializes in treating your cancer type and/or specializes in MRI-guided radiation therapy. Your doctor will determine if you are a candidate for MRI-LINAC treatment based on your cancer type, your situation and whether it is safe for you to get an MRI.

If you are a candidate for treatment on the MRI-LINAC, then you will undergo preparation for treatment with an MRI-LINAC simulation (also known as a planning or mapping) session. Your doctor and team will plan the radiation therapy.

The MRI-LINAC is an FDA (Food and Drug Administration) cleared device. We are committed to safe and effective treatment with this new device and will also be offering patients enrollment on clinical trials to continue to test the value of this new technology.

You will first come in for a simulation (aka planning or mapping) appointment which may include fitting you with a custom immobilization device to help keep you still and in the same position for each treatment.

Before and during this appointment, our team will go through an MRI Safety Screening Form with you and you will be asked to follow specific instructions outlined on Patient Experience During MRI-Guided Radiation Therapy Planning.

You will then undergo a CT scan in our Department, which is used to take images of the more solid structures in your body like bone, that help us calculate our radiation doses. This is an essential step but you’ll only need to do it once. We will perform the CT scan in the same position you will be in for treatment and then we will place a few small tattoo marks on your skin. This will help your team position you correctly each day during treatment.

After the CT scan, we will perform a scan using the MRI in the MRI-LINAC. We will not be treating you at this time, just obtaining this MRI scan so your team can use it to target your tumor.

Using your pre-treatment scans, your physician and a team of highly-trained professionals will work together to create your personalized radiation therapy plan and we will schedule you for your first treatment session.

As with all MRI scanners, you will be lying down on a table and positioned inside a large cylinder.

You’ll need hearing protection because the MRI scanner can be noisy. During treatment, we will give you a set of specially designed headphones, which not only protect your ears but also act as an intercom. This means that you will be in constant contact with your MRI-therapists in the next room. We’ll also give you a small ball to hold. If you have any concerns at all during treatment, you can squeeze the ball and it will act as an alert for your therapists who are outside the room.

We will also have video cameras at your head and feet, which will allow us to monitor you throughout the treatment session.

At the beginning of every treatment session, we will perform an MRI safety screening to ensure nothing has changed since your last visit.

Our team will then position you on the treatment table, take a fresh MRI scan, and compare this new scan with the original scan used to create your radiation treatment plan.

If anything on the scan has changed, your team may need to adapt the radiation treatment plan to account for movement of your tumor and organs.

Once the highly specialized team is satisfied with the radiation treatment plan and targeting, you will receive your treatment.

The radiation delivery on the MRI-LINAC is fully integrated with the MRI. This unique technology means the system can deliver treatment radiation beams and monitor the target area at the same time. The radiation beams are precisely shaped to maximize the dose to the target while minimizing the dose to the surrounding healthy tissue.

While the radiation beam is on, the MRI-LINAC is capturing a constant video of the tumor and/or nearby organs with its MRI and acting on them at sub-second speed. If the tumor or a critical organ moves beyond a boundary defined by your physician, the radiation beam automatically pauses; when the target moves back into the predefined boundary, treatment automatically resumes. What this means is that you get the correct amount of radiation to the correct location.

Call 617-732-6452 to set up an appointment with one of our specialists.