Proton Therapy

Radiation Therapy

Overview

Radiation therapy used for cancer treatment works by depositing energy in tissues containing cancerous cells. If the dose of radiation is high enough, the resulting DNA damage will be sufficient to cause the death of the malignant cells. Unfortunately, radiation has a destructive effect on healthy cells as well. If the dose of radiation to healthy tissue is too high, the damage to structures near the tumor will result in serious treatment induced side effects. The task of the physician is to prescribe a treatment regimen that gives the patient the best chance of a cure with the least amount of complications. Unfortunately, an optimal dose frequently cannot be administered because of the high probability of healthy tissue damage, which can lead to major complications compromising the quality of life of the patient and, in some cases, resulting in secondary tumors.

Proton Therapy

In 1946, Dr. Robert Wilson, a particle physics pioneer, suggested that protons could be used as a form of radiation therapy in the treatment of cancer because of the sharp drop-off that occurs on the distal edge of the radiation dose. Soon after, researchers confirmed that high-energy protons were particularly suitable for treating tumors near critical structures, such as the heart and spinal column. The precision with which protons can be delivered means that more radiation can be deposited into the tumor while the surrounding healthy tissue receives substantially less or, in some cases, no radiation.

Particle accelerators — the devices that deliver proton beams — have been used in cancer therapy for over 50 years, first at the University of California at Berkeley in 1954 and in Uppsala, Sweden in 1957. Today, new facilities specifically designed for proton therapy are being built in many countries. To date, over 80,000 patients worldwide — more than 24,000 in the U.S. — have been treated with protons.

Currently, there are nine proton radiation therapy facilities operating in the United States: CDH Proton Center, A ProCure Center in suburban Chicago; Francis H. Burr Proton Therapy Center at Massachusetts General Hospital; Hampton University Proton Therapy Institute; the James M. Slater, M.D. Proton Treatment and Research Center at Loma Linda University Medical Center; Midwest Proton Radiotherapy Institute; ProCure Proton Therapy Center in Oklahoma City; the Proton Therapy Center at the University of Texas M.D. Anderson Cancer Center; University of Florida Proton Therapy Institute; and the University of Pennsylvania Roberts Proton Therapy Center. Several others are scheduled to open during the next few years.