Study of RapidArc radiosurgery published in Neurosurgery - Varian

The RapidArc Radiosurgery system, from Varian Systems, can be used to deliver treatments for multiple Brain Metastases that are substantially less time consuming and comparable in quality to Gamma Knife (GK) treatments, according to a study slated for publication in the October issue of the journal Neurosurgery. The research team found that the RapidArc Radiosurgery treatment plans for treating multiple tumors in a single fraction are comparable to Gamma Knife plans in terms of how precisely they can conform high doses to match the shape of the targeted tumors, as well as the extent to which RapidArc plans can minimize exposure of normal brain tissue outside the treatment area. A clinical team took 28 previously treated GK cases involving a total of 112 lesions and re-planned them using single fraction RapidArc Radiosurgery. They used a special approach to RapidArc planning that calls for the beam to be delivered using non-coplanar arcs or rotations of the treatment machine around the patient, to maximize the number of treatment angles and enhance precision.

In addition, the approach incorporates key optimization criteria that minimize the amount of low dose "spill" reaching normal brain tissues during treatment. It found that RapidArc Radiosurgery treatments are faster than Gamma Knife treatments for a variety of reasons, including a dose delivery rate that is at least six times faster as well as the ability to treat multiple metastases simultaneously, rather than sequentially. RapidArc Radiosurgery treatments at UAB are completed using frameless immobilization, without affixing the patient's skull to an immobilization frame as required for most Gamma Knife treatments. See: "Comparison of Plan Quality and Delivery Time between Volumetric Arc Therapy (RapidArc) and Gamma Knife Radiosurgery for Multiple Cranial Metastases." Thomas EM et al. Neurosurgery, [Epub ahead of print] October 2014. http://www.ncbi.nlm.nih.gov/pubmed/24871143