A technique for achieving submillimeter accuracy of volume-staged stereotactic radiosurgery
Iijun Ma, Shannon Fogh, Nalin Gupta, Andrew Hwang, Diilni Pinnaduwage, Jean Nakamura, Igor Barani, Michael McDermott, Penny K. Sneed, David A. Larson and Arjun Sahgai
A technique for delivering high-precision volume staged stereotactic radiosurgery has been developed with Leksell Gamma Knife Perfexion for treating large arteriorvenous malformations (AVMs). The technique employs a hybrid method of combining landmark registration and voxel-based 3D image registration to enable multiple staged partial-volume treatments that accommodate repeated stereotactic frame placements. The technique was clinically implemented at our institution and the results were analyzed for a series (n=14) of large AVM cases treated since 2007. Overall, an averaged 0.34±0.09 mm in matching procedural accuracy versus standard single-fraction radiosurgery was found for these treatments. Such a result is a factor of 3-4 times lower than those previously reported, and it approaches the physical accuracy of the latest Leksell Gamma Knife Perfexion system. In conclusion, volume staged radiosurgery has been demonstrated to be deliverable with the same level of accuracy as standard single-fraction radiosurgery.
Keywords: Stereotactic Radiosurgery, Gamma Knife, Treatment Planning, Volume Staging, Arteriovenous Malformation