I have worked in the radiological medical device area for over 30 years, I worked directly for the Siemens applications development department for the nuclear physicist who invented the modern medical LINAC. During the course of my career (I am currently the Vice President of Regulatory Affairs for Direct Medical Systems and consult with other radiological companies on the side) I have met many doctors and PhD's that talk sh*t just so they dont appear stupid. They also tend to use what they have available (and they want the money too). I have personally witnessed patients die on the table during treatment (not H&N mainly lung cancer) while working on LINACS in the field. Many RO's are part owners in the RT treatment centers so a bias may also be present. A typical LINAC will pay for itself in 3 years and has a 6 year span.

Here are some references from the literature - you decide.

http://www.massdevice.com/news/mayo-clinic-gifted-100-million-proton-beam-therapy

http://www.health.state.ny.us/facil...emonstration_project/docs/memorandum.pdf

http://www.hemonctoday.com/article.aspx?rid=33481

http://www.communityoncology.net/journal/articles/0410599.pdf

http://www.astro.org/Research/CommentForm/documents/ProtonReport2010.pdf (scroll down to page 62)

http://www.protons.com/proton-therapy/conditions-treated/head-and-neck.html