Items needing resolution

"Before the Clinac 4, only a very small fraction of all cancer patients could be effectively treated with radiation. Today that number has risen over 600,000 patients per year in the U.S." (from Levy talk)
- Citation for number?
- Patients treated just by Varian machines? Or by any machine?
- What is a Clinac 4? Wasn't the first Clinac the Clinac I? —Preceding unsigned comment added by Randomandy (talk • contribs) 06:26, 21 September 2010 (UTC)[reply]