3. Proton therapy is a type of radiation treatment that uses protons to treat cancer. At
high energy, protons can destroy cancer cells.
The first suggestion that energetic protons could be an effective treatment method
was made by Robert R. Wilson in a paper published in 1946.
The first treatments were performed with particle accelerators built for physics
research.
In 1961, a collaboration began between Harvard Cyclotron Laboratory (HCL) and
the Massachusetts General Hospital (MGH) to pursue proton therapy.
As of April 2017, there are over 74 particle therapy facilities worldwide, with at least 42
others under construction. As of the end of 2015 more than 154,203 patients had been
treated.
6. The proton center uses a Protheus
230 cyclotron, a cyclic high frequency
accelerator, which accelerates protons
up to an extremely high speed -
thereby producing a beam of high
energy (E = 230 MeV).
CYCLOTRON-
7. The Beam Transport System is a
system that transports proton beams
from the cyclotron through a vacuum
tube - leading to the irradiation
nozzles of each treatment room.
BEAM
TRANSPORTATION
SYSYTEM
8. A proton beam that is produced in a cyclotron has a specific level of energy that can be
adjusted using an Energy Selection System.
The energy of a proton beam is determined by the depth of the tumour within the body
of the patient (e.g. a proton beam with an energy level of 230 MeV acts at approximately
a depth of 30 cm of tissue).
Materials such as graphite, with a low number of protons , are used for reducing the
energy of the beam.
Secondary adverse radiation is produced during this process, such as neutrons, scattered
protons, gamma radiation, etc.
Energy selection system is also designed to completely filter out these types of adverse
radiation .
ENERGY SELECTION SYSTEM
10. PENCIL BEAM SCANNING
Proton beam delicately and precisely
moves a beam of pencil point sharpness
back and forth across each layer of the
tumor’s thickness with radiation in three
dimensions.
It is an ideal treatment for irregularly
shaped tumors that are located next to
critical tissues and organs such as brain
or eye.
11. The ability of the proton dose to
increase at a specified area is called
the Bragg Peak.
The depth of the Bragg Peak in
tissue is dependent on the energy
of the beam; the higher the energy,
the deeper the Bragg Peak and
therefore, the deeper the dose.
BRAGG PEAK-
17. PROTON CT
An international team of scientists has
produced the world's first computerised
tomography (CT) images of biological tissue
using protons to more accurately target the
tumour.
Currently in Proton Therapy, there is a
significant degree of uncertainty of 3-5% in
terms of where the proton beam hits
destroying cells . With proton CT images, this
uncertainty is reduced to less than 1%.