MRI-Guided Radiation Therapy

Unlike standard radiation therapy, MRI-guided radiation therapy allows your doctor to track and dose your tumor in real time. MRI-guided radiation therapy combines diagnostic MRI imaging with a linear accelerator. This allows your doctor to see in real time if the tumor has shifted due to movement from the bowels, regular breathing, or your heart beating, for example. Radiation delivery will stop when the tumor moves, which greatly decreases the amount of radiation hitting healthy tissues and organs. Radiation delivery will only begin when the tumor has returned to the correct treatment area.

This precision means your tumor can receive a stronger cancer-destroying radiation dose and decrease negative side effects at the same time. MRI-guided radiation therapy is the safest method available to treat tumors of the abdomen due to its ability to adapt in real time.

Traditional methods of radiation treatment include your doctor taking CT scans before treatment. This imaging does not account for normal body movements such as breathing and movement of internal organs. These movements can cause your tumor and healthy tissues to move before and during treatment. This puts your healthy tissues at risk of being damaged by radiation. With real time MRI, your doctor can usually deliver your radiation treatment in fewer sessions and with less damage to healthy tissue.

Providence Cancer Institute has expanded the types of cancer that can be treated with MRI-guided radiation therapy. We will continue to add tumor types as they become eligible for treatment.

Tumor types now include:

• Abdomen (liver cancer, pancreatic cancer, metastases to liver, adrenal and other areas)
• Pelvis (prostate cancer, metastases to pelvis)
• Spine
• Breast

Candidates for MRI-guided radiation therapy are patients who:

• Can safely receive MRI
• Are in relatively good shape and can tolerate lying down for 30-60 minutes
• Cancer is limited in size and number (to be determined by the treating radiation oncologist)

Your first appointment is dedicated to planning and personalizing your treatment. This may include pre-treatment scans and fitting you with accessories that help you lay in a more comfortable and consistent position for each visit.

At the beginning of every treatment session, we will help you get into the correct position. Then, we will take an MRI scan. The new scan will be compared to the original scan, so your treatment can be adjusted for the best possible outcome.

You will be fitted with special headphones to protect your hearing from the noise. These headphones not only protect your ears, but they also act as an intercom to keep you in contact with your doctor in the next room.

The radiation and MRI machines work together in real time, so the radiation beams maximize the dose to your tumor and minimize the dose to your surrounding organs.

While the radiation beam is on, the MRI machine is constantly capturing images of your surrounding organs. If your tumor or surrounding organs move past the area allowed by your doctor the radiation beam automatically pauses. When the target moves back into the allowed area the radiation beam automatically turns back on. This allows you to get the correct amount of radiation to the correct location.

Every patient will have a different treatment plan. Treatment sessions are usually thirty minutes to one hour, and patients usually receive three to five treatment sessions a week over the course of one to two weeks.

Talk with your doctor about when you will be able to resume normal activities. This timeline will depend on your specific treatment plan and activities.