IU’s Midwest Proton Radiation Institute proton beam to treat cancers with advanced forms of radiation therapy

By Susan Williams

Proton therapy has become widely accepted and used in the treatment of head and neck tumors, prostate cancer, ocular melanoma and neurosurgery, said Cameron. And clinical studies are under way for lung and rectal cancer, as well as macular degeneration.

Efforts to develop a plan for finding the financial support to treat cancers with advanced forms of radiation therapy using proton beam from IUCF began as early as 1990. But it wasn’t until 1996 that a consortium of physicians and scientists collaborated to form the MPRI, an independent radiation therapy center.

While physical structures—which also will include an adjacent 14,800-square-foot building to house up to 20 families that come to the institute seeking treatment and a hospital-like clinical facility—are well on the way, the staff for the facility is complete for now.

Dr. Allan F. Thornton comes to IU from the Harvard Cyclotron Laboratory and Massachusetts General Hospital, where he specialized in proton therapy for advanced head and neck tumors, as well as stereotactic proton and photon radiosurgery for brain lesions. As medical director of MPRI, his responsibilities include development and recruitment of resources, coordination of architectural, engineering and systems designs, patient care (validation of diagnosis, treatment delivery and follow-up), and management of staff.

With 12 years of experience in treating more than 1,500 patients in South Africa at the National Accelerator Centre, Andries (Niek) Schreuder is head medical physicist. He will handle all aspects of medical physics at MPRI, including the design and construction of the medical beam lines and beam delivery systems, treatment planning and patient positioning.

IUCF radiation biologist Susan Klein has been involved in the formation of a medical facility since the beginning. She is clinical, pre-clinical and radiobiological researcher and coordinator, and manager for MPRI clinic design. In addition, Klein has two ongoing research projects, one of which involves evaluating therapy for choroidal neurovascular membrane in age-related macular degeneration in collaboration with the Department of Ophthalmology at the IU School of Medicine, the IU School of Optometry, and radiation oncologists from Methodist and IU Hospitals.

The cyclotron facility, itself, receives funding from IU, the National Science Foundation and the U.S Department of Energy. It is a national research center where the process of accelerating, scattering and detecting subatomic particles is carried out on a large scale with approximately 200 scientists, technical staff and students from around the world involved with experiments there each year.

At the laboratory’s center is the accelerator itself, which consists of an ion source, a small synchrotron ring that accumulates and accelerates subatomic particles from the source, and an electron-cooled storage ring that can increase particle energy as it prepares the beam of particles for experimental use.

The cyclotron system provides protons with energies up to 200 million electron volts (MeV), while the synchrotron-cooler ring can increase this to greater than 500 MeV. At this energy, protons are moving at about 140,000 miles per second, just over three-quarters of the speed of light.

Most medical advancements are met with criticism, and proton therapy has been no exception, but the medical staff are believers. “The physics and radiobiology of particle therapy indicate that we have explored only the tip of the iceberg,” said Klein.

Proton therapy has become widely accepted and used in the treatment of head and neck tumors, prostate cancer, ocular melanoma and neurosurgery, said Cameron. And clinical studies are under way for lung and rectal cancer, as well as macular degeneration.

But the bottom line is found in successful treatment.

“With the use of proton therapy, 10-year cure rates for patients with tumors at the base of the skull have increased from 35 percent to 75 percent,” said Thornton. “Additionally, the five-year control rate for patients with paranasal sinus tumors have increased from 25 percent to 85 percent. Just today, I received a follow-up note on a gentleman treated in 1992 with an advanced sinus tumor, conventionally thought to be cured only 25 percent of the time, now without disease almost 10 years later.”