Proton beam radiotherapy (PBRT) is widely regarded as the optimal radiation treatment for a wide variety of cancers because of its significant clinical advantages compared to conventional high energy x-rays.
The goal of radiotherapy
The goal of radiotherapy, which is used to treat more than half of all cancer patients, is to deposit as much energy (or dose) in a cancer tumor as possible while minimizing the dose that reaches the surrounding normal tissue. This is because the beams of high energy used in radiotherapy can damage the DNA of cancerous cells as well as non-cancerous ones. Thus the more focused and accurate the beam is, the higher the dose that can be delivered to the tumor while minimizing the potential for collateral damage.
Radiotherapy techniques that minimize side effects
Conventional high-energy x-rays (photon radiotherapy) deposit dose along the entire energy beam path to the tumor as well as beyond the depth of the tumor. Radiation oncologists employ several techniques to minimize collateral damage to adjacent tissue: targeting the tumor from different angles, tailoring the beam to conform to the shape of the tumor, and modulating the intensity of the radiation delivered to different parts of the tumor.
How is proton radiotherapy different?
Proton radiotherapy deposits most of its energy at a specific depth and then stops entirely. This allows the physician to tailor the deposition of dose to the specific depth and shape of the tumor while simultaneously reducing the damage to surrounding normal tissue. The advantages of proton radiotherapy over conventional radiotherapy are emphasized in areas of the body with critical adjacent structures (e.g. eye, brain, base of the skull, spine, and prostate) as well as in pediatric tumors.
History of proton radiotherapy
Proton radiotherapy was first proposed in 1946 and by 1954 the first patient had been treated. From the early 1960's until the late 1980's, proton therapy was investigated for clinical efficacy at small research facilities. The first hospital based proton facility opened at the Loma Linda University Medical Center in California in 1990. About twenty institutions around the world have since installed proton therapy systems and treated over 50,000 patients. Still River Systems is dedicated to dramatically increasing the availability of this form of therapy to cancer centers, physicians and patients around the world.