Scientific Presentations at 2011 AAPM/COMP Meeting Highlight TrueBeam™ and RapidArc® Radiotherapy Systems From Varian Medical Systems | Varian

Scientific Presentations at 2011 AAPM/COMP Meeting Highlight TrueBeam™ and RapidArc® Radiotherapy Systems From Varian Medical Systems

VANCOUVER, British Columbia, Aug. 9, 2011 /fr/PRNewswire/fr/ -- Medical physicists researching RapidArc® radiotherapy technology from Varian Medical Systems (NYSE: VAR) have reported that, compared with conventional approaches to radiotherapy, RapidArc treatment plans for lung, abdominal and spinal tumors do a better job of sparing healthy tissues and organs.

Presenting at a professional conference of medical physicists last week, a team from Mount Sinai Medical Center in New York reported that a RapidArc treatment plan for treating a single complex case of lung cancer spared more healthy tissues and critical organs than a treatment plan for IMRT or 3-D conformal radiotherapy.  In this treatment plan comparison study, the average dose to healthy lung tissues was 8 Gy lower for the RapidArc plan as compared with the other two treatment approaches. The amount of healthy tissue receiving 10-20% of the prescribed dose—a common way of measuring how much healthy tissue is being impacted—was 45% to 50% lower for the RapidArc plan, compared to the other two plan types.  In addition, the investigators found the RapidArc plan offered better tumor coverage than the 3-D conformal radiotherapy plan.(1)

"RapidArc for whole abdominal irradiation in patients offers better homogeneity with the same level of kidney sparing while providing more sparing of organs at risk, such as the bone marrow," concluded a team of researchers from North Shore Long Island Jewish Health System, in a poster presentation comparing RapidArc with a more conventional 2-beam approach to whole abdominal radiotherapy for a single patient.  For example, the amount of healthy bone marrow receiving up to 90% of the prescribed dose went from 95.13% with the conventional treatment plan down to 18.4% in the RapidArc plan.(2) Whole abdominal radiotherapy is often prescribed for some gynecological and gastrointestinal cancers.

Clinicians from St. Luke's Hospital in Bethlehem, Pennsylvania, described an approach to RapidArc treatment planning that enabled them to achieve superior dose distributions for treating spine tumors with stereotactic radiosurgery.  Their poster presentation studied the dosimetry characteristics of 11 RapidArc treatment plans for spinal tumors, and concluded that their RapidArc plans "allow for extremely rapid dose fall off," which means that outside the target area, the dose levels drop very quickly to help protect surrounding healthy tissues.(3)

RapidArc delivers a precise and efficient treatment in a single or multiple arcs of the treatment machine around the patient and makes it possible to deliver image-guided radiotherapy treatments two to eight times faster than is possible with conventional approaches such as fixed-field IMRT or 3-D conformal radiotherapy.

The scientific program at the 2011 joint meeting of the American Association of Physicists in Medicine (AAPM) and the Canadian Organization of Medical Physicists (COMP) included other notable presentations and posters: