Pencil beam scanning is the practice of steering a beam of radiation or charged particles across an object. It is often used in
proton therapy
In medicine, proton therapy, or proton radiotherapy, is a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often to treat cancer. The chief advantage of proton therapy over other types of external beam ra ...
, to reduce unnecessary radiation exposure to surrounding non-cancerous cells.
Ionizing radiation
Ionizing radiation
Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel ...
photons or
x-rays (
IMRT) use pencil beam scanning to precisely target a tumor. Photon pencil beam scans are defined as crossing of two beams to a fine point.
Charged particles
Several
charged particles devices used with
Proton therapy
In medicine, proton therapy, or proton radiotherapy, is a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often to treat cancer. The chief advantage of proton therapy over other types of external beam ra ...
cancer centers use pencil beam scanning. The newer proton therapy machines use a pencil beam scanning technology.
This technique is also called spot scanning. The
Paul Scherrer Institute was the developer of spot beam.
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Intensity Modulated Proton Therapy
Varian's IMPT system uses all pencil-beam controlled protons where the beam intensity can also be controlled at this small level. This can be done by going back and forth over a previously radiated area during the same radiation session.
See also
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Pencil (mathematics)
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Pencil (optics)
In optics, a pencil or pencil of rays is a geometric construct used to describe a beam or portion of a beam of electromagnetic radiation or charged particles, typically in the form of a narrow beam (conical or cylindrical).
Antennas which strong ...
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