Proton Beam Therapy for Brain and Spine Tumors

Neurological Institute – January 2017

 Andrew Sloan, MD

University Hospitals Cleveland Medical Center is among a select group of centers in the U.S. that offer proton beam therapy for brain, spine, and other tumors.

Proton beam therapy is another potential treatment for adults and children with various types of tumors. This approach is particularly valuable for brain and spine tumors because it eliminates some of the unnecessary dose exposure to uninvolved tissues.

“The beauty of proton beam therapy is the Bragg peak effect—98 percent of the dose is delivered to a specific point,” says Andrew Sloan, MD, Peter D. Cristal Chair in Neurological Oncology, Director, Brain Tumor and Neuro-Oncology Center, Vice-Chairman, Department of Neurological Surgery, UH Cleveland Medical Center; Professor of Neurosurgery, Case Western Reserve University School of Medicine “There’s virtually no entry or exit dose.”

Tumors surrounded by sensitive normal tissue, such as in the brain, the lung, and the chest are potential candidates for proton beam therapy, so there is a decrease in radiation exposure where it is not needed.

Both proton therapy and traditional radiation treat tumors in the same way: by killing cancer cells or inhibiting their growth. The most significant difference between the two is that proton beams travel to a specific depth and then stop, rather than continuing through the body. This provides a proportionately higher dose in the tumor, and relatively less in surrounding normal tissues.

Conventional radiation therapy uses X-ray, or photon, beams. Photon beams enter the body, depositing significant energy in healthy tissue before and after they pass through the tumor. The photons’ lack of charge and mass means most of their energy is deposited in normal tissues near the body's surface, as well as areas of the body beyond the site of the cancer.

Similar to conventional high energy X-rays, proton therapy is an external beam radiation therapy technique. The difference is that protons are larger and heavier charged particles that deposit radiation dose in a more targeted manner. By changing the energy of the proton beam, radiation oncologists can tailor the proton dose to the specific depth and shape of the tumor, while greatly reducing the dose to surrounding healthy tissue.

In addition to brain and spine tumors, proton therapy may be an effective option for:

• Gastrointestinal cancer
• head and neck cancer
• Lung cancer
• Lymphomas
• Many types of pediatric cancers
• Prostate cancers
• Sarcomas
• Patients who have already had conventional radiation treatment

Having proton beam therapy available at University Hospitals gives surgeons another tool in their arsenal to treat tumors, Dr. Sloan said. The short-term side effects of proton beam therapy are similar to traditional X-ray treatment. However, the long-term edge that proton beam therapy offers includes potentially decreasing the risk for malignancies that are radiation-induced.

Proton beam therapy was only available at three centers in the U.S. in the mid 2000s, and even today, only a couple dozen centers offer it. The availability of proton beam therapy at the UH Seidman Cancer Center offers this unique treatment option not only to Cleveland residents but also geographical areas such as Pittsburgh; Rochester, NY; and Detroit. University Hospitals Cleveland Medical Center is the first hospital to bring this technologically advanced therapy to Ohio.

For more information about the UH Proton Therapy Center, please call 216-286-PROT or visit UHhospitals.org/Proton.