Graphene is an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in an hexagonal lattice. It is the basic structural element of many other allotropes of carbon, such as graphite, charcoal, carbon nanotubes and fullerenes.
In cases where surgery and radiation are combined, proton therapy is an ideal part of brain cancer treatment. Different brain tumors require different doses of radiation for control and eradication. Like any other organ in the body, the brain can only tolerate a limited amount of radiation.
External-beam radiation therapy is most often delivered in the form of photon beams (either x-rays or gamma rays) . A photon is the basic unit of light and other forms of electromagnetic radiation. It can be thought of as a bundle of energy. The amount of energy in a photon can vary. For example, the photons in gamma rays have the highest energy, followed by the photons in x-rays. Linear Accelerator Used for External-beam Radiation Therapy. Many types of external-beam radiation therapy are delivered using a machine called a linear accelerator (also called a LINAC).