PALO ALTO, Calif., Aug. 8, 2011 /PRNewswire/ -- RapidArc® radiotherapy from Varian Medical Systems (NYSE: VAR ) can be used to treat patients with blood cancers by quickly and accurately delivering "clinically favorable" total marrow irradiation (TMI), according to a team of noted cancer treatment experts who spoke at the 2011 joint meeting of the American Association of Physicists in Medicine (AAPM) and the Canadian Organization of Medical Physicists (COMP) in Vancouver last week. Their recent study  on this topic, which is available online as an article in press ahead of publication, is slated to appear in an upcoming issue of the International Journal of Radiation Oncology*Biology*Physics.(1)
"Compared to conventional IMRT and tomotherapy, RapidArc appears to improve on the dose distribution, in terms of normal tissue sparing, as well as on the efficiency of treatment," said Bulent Aydogan, PhD, associate professor of medical physics at the University of Chicago and the director of medical physics at the University of Illinois at Chicago.
Aydogan and his collaborators planned and delivered, in their recent dosimetric feasibility study, RapidArc TMI treatments for six patients, and subsequently compared the treatment plan parameters, including median dose, mean dose, and maximum dose, to fixed-gantry and tomotherapy plans for the same cases. They found that RapidArc produces dose distributions that are comparable to conventional intensity-modulated radiotherapy (IMRT) in terms of target coverage, but with improved normal tissue sparing.
The RapidArc treatments could also be delivered much more efficiently, requiring approximately 18 minutes once a patient was positioned for treatment. By comparison, treatment times of 45 to 50 minutes have be