Gamma Knife Tomosurgery

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Track Code CWRU001 ​Abstract The current worldwide standard-of-care for radiosurgical treatment of intracranial lesions utilizes a step-and-shoot dose delivery mechanism. This mechanism requires repositioning the patient outside of the irradiation field. Accordingly, the treatment team faces a significant challenge in planning the treatment of a large and/or complexly shaped lesion in close proximity to vascular structures. The standard manual planning approach is very time consuming and does not necessarily guarantee the identification of an increasingly optimal treatment plan. The subject technology is a new radiosurgery paradigm referred to as "Tomosurgery". The Tomosurgery paradigm begins with the division of the target volume into a series of adjacent treatment slices, each with a carefully determined optical thickness. The use of a continuously moving disk-shaped radiation shot that moves through the lesion in a raster-scanning pattern improves overall radiation dose conformality and homogeneity. The Tomosurgery treatment planning algorithm recruits a two-stage optimization strategy, which first plans each treatment slice as a simplified 2D problem. Secondly, the 2D treatment plans are optimally assembled into the final 3D treatment plan. Tested on 11 clinical cases, the automated Tomosurgery treatment plans performed as well or better than the neurosurgeon's manually created treatment plans across all criteria, including (a) dose volume histograms, (b) dose homogeneity, (c) dose conformality, and (d) critical structure damage. The development of this technology was funded in part by the Coulter-Case Translational Research Partnership.