MR-Linac Radiation Therapy

MR-Linac treatment combines highly targeted radiation therapy with the imaging precision of magnetic resonance imaging (MRI). The linear accelerator, or Linac, delivers high-dose radiation to patients inside an MRI machine. The machine constantly obtains images during treatment, providing high-resolution images of the tumor and control of the radiation beam in real time.

This allows your care team to deliver high-dose radiation to tumors that can change shape or move during treatment – such as tumors of the head and neck, abdomen or pelvis – while minimizing the amount of healthy tissue irradiated. 

Types of cancers MR-Linac can treat

MR-Linac radiation therapy is most commonly used for intact (non-surgical) cases where monitoring the tumor’s location during daily treatment is important, or when tumors are expected to shrink or change shape during radiation treatment.

Traditional radiation therapy can damage healthy organs and tissue. The organs of the abdomen and chest constantly move as we breathe. This can make it harder for the radiation beam to remain on the tumor during treatment and can cause healthy organs and tissue to receive the radiation instead.

Additionally, some tumors shrink or change during radiation, which can also cause radiation damage to healthy tissue. The high image quality of MR-Linac makes it possible for the treatment team to deliver high doses of radiation to the tumor with less damage to surrounding healthy tissue, or to adapt so that each treatment is more accurate.  

The MRI may also give doctors information about the biology of the tumor and normal tissue. This can be used to monitor and optimize the patient’s treatments. 

Some examples of tumors MR-Linac can be used to treat include:  

• Chest tumors, like lung cancer
• Rectal cancer
• Head and neck cancers, like oral cancer
• Gynecologic cancers, including endometrial cancer and cervical cancer
• Liver cancer
• Bladder cancer
• Prostate cancer
• Kidney cancer
• Spine tumors
• Brain cancer
• Breast cancer

Is MR-Linac right for me?

Candidates for treatment on the MR-Linac should be able to undergo an MRI. Sometimes, metallic objects in the body (such as certain implanted medical devices) mean that a patient should not get an MRI. However, many times, patients with certain types of metal or electronic objects in the body can receive MR-Linac treatment; your doctor can help you understand if this is an option.

Patients with severe claustrophobia may find the MR-Linac (like any MRI) uncomfortable; your doctor may give you medications to help with anxiety if this is the case.

MR-Linac treatments are often combined with brachytherapy (a type of interventional radiation therapy) for gynecologic tumors, and chemotherapy or immunotherapy for many other tumor types.

MR-Linac side effects

MR-Linac reduces the risk and severity of side effects associated with traditional radiation. This means less healthy tissue is irradiated and fewer treatments are needed. 

For example, standard external beam radiation for prostate cancer can cause short-term painful and/or frequent urination, diarrhea and rectal urgency. It can also cause long-term side effects such as urinary stricture (scarring that narrows the urethra -the tube carrying urine out of the body), cystitis (a bladder infection and common urinary tract infection), proctitis (inflammation of the rectum), and sexual dysfunction. MR-Linac treatment can significantly improve the patient’s quality of life by reducing radiation’s impact on urinary and intestinal function.

MR-Linac patients may experience some of the side effects of radiation treatment, including:

• Nausea
• Fatigue
• Loss of appetite
• Hair loss
• Red, itching and peeling skin in the treatment area

MR-Linac treatment at MD Anderson

MD Anderson was the first hospital in the U.S. to treat patients with the MR-Linac, and our pioneering teams have conducted groundbreaking research in this new technology.

MD Anderson has developed MR-Linac treatment for head and neck cancers, gynecological cancers and cancers of the spine, prostate, brain, kidney and breast. 

At MD Anderson, MR-Linac therapy involves a dedicated team of physicists, therapists, dosimetrists and physicians. They are committed to delivering the most accurate radiation, adapted to your specific tumor and normal tissue in real-time, allowing for personalized radiation therapy.