How different is proton therapy from x-ray therapy?

X-ray therapy and proton therapy are both radiation therapy techniques but the former uses photons to irradiate diseased tissues while the latter uses beams of energetic protons, which have very different physical properties.

The concept of photon has been developed by Einstein and is based on its behavior as both a particle   and an electromagnetic wave. This defines the nature of light. Electromagnetic waves widely exceed the visible spectrum. Radio waves, micro-waves, infrared rays, UV, x-rays are all invisible light occurrences, some of which are able to interact with matter and ionize it. This explains how ultraviolet radiation from sunlight causes sunburns (UV photons interact with skin) and why x-ray radiotherapy uses photons to irradiate tumors and destroy bad cells.

Protons, on the other hand, are subatomic particles with a positive electric charge that coexist with neutrons in the nucleus of each atom, around which the electrons revolve. Those charged particles, when isolated and highly accelerated (by a particle accelerator such as a cyclotron), are also able to ionize our cells, which constitutes the operating principle of proton therapy.

Photons have no mass and no charge, whereas protons are considered as “heavy” particles (1,67 x 10-27 kg) and are positively charged. Consequently, they interact very differently with matter and human living cells, and that is precisely where the chief advantage of proton therapy relies.

Information sources:

X-ray therapy and proton therapy are both radiation therapy techniques but the former uses photons to irradiate diseased tissues while the latter uses beams of energetic protons, which have very different physical properties.

 

The concept of photon has been developed by Einstein and is based on its behavior as both a particle   and an electromagnetic wave. This defines the nature of light. Electromagnetic waves widely exceed the visible spectrum. Radio waves, micro-waves, infrared rays, UV, x-rays are all invisible light occurrences, some of which are able to interact with matter and ionize it. This explains how ultraviolet radiation from sunlight causes sunburns (UV photons interact with skin) and why x-ray radiotherapy uses photons to irradiate tumors and destroy bad cells.

 

Protons, on the other hand, are subatomic particles with a positive electric charge that coexist with neutrons in the nucleus of each atom, around which the electrons revolve. Those charged particles, when isolated and highly accelerated (by a particle accelerator such as a cyclotron), are also able to ionize our cells, which constitutes the operating principle of proton therapy.

 

Photons have no mass and no charge, whereas protons are considered as “heavy” particles (1,67 x 10-27 kg) and are positively charged. Consequently, they interact very differently with matter and human living cells, and that is precisely where the chief advantage of proton therapy relies.

 

Information sources:

·         http://en.wikipedia.org/wiki/Proton_therapy