Proton Therapy
Proton Therapy has come about out of issues with the use of X-rays. Essentially the benefit is added precision and dosage of radiation. X-rays disperse from the line of fire and also continue through the tumour therefore striking surrounding, healthy, cells. Protons however, (when excited, accelerated and focused into a beam) can be fired precisely with very little deviance from the original set path. Essentially it is like using a rifle to hit a tumor as a pose to a shotgun.
Energized charged particles are used during radiation treatments as high doses prove to damage cell tissue, specifically in the DNA, which serves to stop cancerous cells from uncontrollably dividing and kills the cell. The removal of an electron from a proton (ionisation) causes the proton to attract other electrons from atoms within the cell, therefore altering the characteristics of that atom and subsequently, the cell as a whole. The cyclotron achieves this by using enourmously powerful magnets to strip electrons from hydrogen in water molecules before accelerating them and firing them.
The ability to focus the beam and change its cross sectional shape to that of the tumour's is achieved using a mulitleaf collimator. This mathing of the apertures shape to that of the tumour's shape is what makes the treatment so precise and reduces the amount of radiation damaging tissues elsewhere in the body. The reason X-rays travel further into the body is down to their reduced size and energy comparing to protons, causing them to be deposited at shallower distances than desired, or pass straight through and continue on to areas "behind" the tumour. This process can be carried out in multiple planes and is therefore very precise.
The use of higher dosages of radiation and decreased number of healthy cells being unnecessarily exposed to radiation are what make proton therapy a more attractive treatment option to some.