Proton-Beam Radiotherapy

When S. Lee Kling, the late chairman of the Barnes-Jewish Hospital Foundation Board and a well-known St. Louis philanthropist, was diagnosed with a tumor near his eye, he was determined to save his sight, recounts Dr. Jeff Bradley, a radiation oncologist with Washington University Physicians.

    “One option was to have surgery and treatments that would likely have cost him his eye,” Bradley continues. “Instead, Mr. Kling underwent proton beam radiotherapy, which targeted the tumor while sparing the eye. But he had to go to Boston for the treatment. Subsequently, he felt it was important to offer proton radiotherapy in St. Louis. His generosity is helping to make that possible.”

    Bradley will serve as medical director of the Kling Center for Proton Therapy, part of the Siteman Cancer Center. Before Kling’s death in July 2008, he led an effort that raised $2.3 million to fund research and use of the proton facility. Bradley anticipates the Kling Center will open late next year or early in 2011.

    The Kling Center will be the first single-vault proton therapy center in the country, and the equipment will be assembled and given its first trial at Siteman Cancer Center. Currently, there are six proton radiotherapy facilities in the United States, but the system being designed and tested for the Kling Center will cost about one-fifth of the standard $100 million or more and will fit in a much smaller area.

        “Proton radiotherapy allows us to very precisely target the treatment beam to the tumor while limiting radiation exposure to nearby tissue,” Bradley explains. “But the cost of building a full-scale center like the ones operating today, which house a large cyclotron and several treatment rooms, has been prohibitive. Our hope is that this more affordable type of proton facility will allow for more facilities to open and more people to have access to this treatment option.”

    Radiation therapy is a standard treatment for many types of cancers, often along with chemotherapy and surgery. High-energy radiation kills cancer cells or prevents them from multiplying. However, some healthy cells also are exposed to radiation during the therapeutic process. Minimizing this exposure is one of the advantages to proton radiotherapy.

    “Most radiation therapy uses photons, which are particles that penetrate all the way through the body, like X-rays,” explains Dr. Peter Johnstone, president of the Midwest Proton Radiotherapy Institute (MPRI), a program within the Indiana University Simon Cancer Center, in Bloomington, Ind. Proton beams, unlike X-rays, can stop at various depths in the body, sparing more healthy tissue from radiation exposure.

    The proton beam provides a lower dose of radiation to the tissues in front of the targeted tumor, a high dose to the tumor itself, and no dose at all beyond the tumor. “This precise targeting ability makes proton therapy valuable for treating tumors in children and near vital organs, especially the brain,” he says.

    Minimizing radiation exposure in children is important because of the risk of secondary cancers later in life due to the irradiation of healthy cells. And because proton radiotherapy may result in fewer side effects than traditional radiation, children may tolerate it better. Cancers of the eye, head, neck, bladder, prostate, pancreas, spinal cord and lungs are among those that have been treated with protons.

    Seventy percent of the patients seen at MPRI come from outside Indiana, and 250 patients were treated at the facility last year, says Richard Helsper, MPRI’s chief operating officer. He adds that most insurance plans and Medicare cover proton radiotherapy treatments.

    “People should explore all their options,” Helsper says. “Proton therapy is not for everyone, but it’s one tool in the cancer-fighting arsenal, and it’s available in the Midwest.”