Has anyone tried cyberknife treatment? My husband has a single cancerous lymph node that has already been radiated and he's done chemo also. It's come back again.

It certainly sounds attractive.... imagine you only need one treatment. The (single) radiation dose is big enough to kill the cells.
From what I glean cyberknife is good for well defined and (smallers) tumors while IMRT is for larger and more irregular tumors... Cyberknife could potentially be used for reirradiation (lower dose)

Anyway, here is some info for you:
http://www.oralcancerfoundation.org/news/news.asp?offset=420
http://patienteducation.upmc.com/Pdf/CyberKnifeNeck.pdf

Markus