PALO ALTO, Calif., Jan. 10, 2011 -- Varian Medical Systems (NYSE: VAR) has received FDA 510(k) clearance for the Varian Proton Therapy System which generates protons for precision radiotherapy of lesions, tumors, and conditions anywhere where radiation treatment is indicated. It is the first working system capable of delivering precise intensity modulated proton therapy (IMPT) using pencil beam scanning technology.