This difficulty can be circumvented by the use of radioisotope plaques, but this technique involves surgical implantation, hospitalization and surgical removal of the plaque. External proton beam radiotherapy is another alternative which has the capability of treating microscopic targets without affecting the surrounding healthy tissue. Because proton beam therapy is an external beam radiation, surgery and hospitalization are not required. Proton Radiation Therapy for AMD Protons are subatomic particles that can be accelerated and focused by electromagnetic fields. Unlike X-rays, which are high energy forms of visible light, protons have mass and charge, and therefore behave in a fundamentally different way.
Protons release most of their energy when they stop.
The distance protons travel through tissue can be determined by their initial energy. Healthy tissues beyond the Bragg peak receive no radiation. It is therefore possible to deliver relatively large doses of radiation to the CNV while sparing the retina, lens, optic nerve, healthy vascular tissue, and other critical neurological tissues. Patients were recruited into the the trial between June of 1998 and March of 2000. Proton radiation was delivered by the Midwest Proton Radiation Institute at the Indiana University Cyclotron Facility in Bloomington, Indiana.