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Why is MRI guidance needed?

Why is MRI the best kind of imaging to use with radiotherapy?

What kinds of cancer can be treated with MRI-guided radiotherapy?

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CT lung

MRI-Guided Radiotherapy

Why is MRI guidance needed?

Radiation treatments must be extremely precise, yet our internal organs don't stay locked in place. When we breathe or swallow, when our bodies digest food or we reach to scratch an itch, our internal tissues shift. Even tiny movements can affect the position of a tumor that's being targeted for treatment.

Here's an example: If you have lung cancer, your tumor will move as you breathe—as much as a few centimeters (an inch or more) every three to four seconds—and it won’t always move along the same path. With MRI-guided radiotherapy, your physician can monitor the tumor’s motion throughout the treatment and pause the delivery of the radiation dose if the treatment target shifts because of your breathing or any other movement.

ViewRay technology has the potential to improve the cancer treatment of organs that move naturally. When physicians can be sure that the radiation beam is in exactly the right place at all times, hitting the tumor and avoiding healthy tissue, patients may experience better outcomes and reduced side effects.

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soft-tissue imaging

MRI is the clinically preferred method of imaging soft tissue. Compared to CT imaging (below), MRI technology can give clinicians a clearer, more detailed view of the patient’s internal organs—such as the prostate shown above—without delivering the extra ionizing radiation of CT.

CT prostate image

CT image

Why is MRI the best kind of imaging to use with radiation therapy? 

MRI is the clinically preferred method of imaging soft tissue. MRI technology gives clinicians a clearer view of a patient’s internal organs. Computed tomography (CT) images which are commonly used with other radiation therapy devices, are not as clear. CT imaging also delivers additional, unnecessary radiation to the patient, while MRI does not.

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What kinds of cancer can be treated with MRI-guided radiation therapy?

The MRIdian system can be used to treat lesions, tumors, and conditions anywhere in the body where radiation therapy is prescribed. Physicians are finding MRI-guided radiotherapy to be of particular interest in the treatment of tumors that move significantly—tumors in areas like the lungs or liver, where the body's soft tissues shift naturally and the delivery of precise treatments is more challenging. ViewRay technology may also be beneficial in monitoring movement with tumors in prostate, breast, bladder, head and neck, and other types of cancer where tumor and organ motion can affect treatments. 

Ask your radiation oncologist if MRI-guided radiotherapy is right for you.

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