Particle physics is awesome enough all by itself. It gets even more awesome when we see the spin off technologies that have been developed over the decades!
The basics of radiation and hadron therapy are summed up quite well on wikipedia:
http://en.wikipedia.org/wiki/External_beam_radiotherapy
http://en.wikipedia.org/wiki/Particle_therapy
http://en.wikipedia.org/wiki/Proton_therapy
Images taken from:
Bragg peak: http://en.wikipedia.org/wiki/File:BraggPeak.png
Paul Scherrer Institut gantry: http://www.psi.ch/history-of-psi
Radiative therapy dose map: http://www.sciencedirect.com/science/article/pii/S0360301607005068
Tags: advent calendar 2012