Journal: Journal of Applied Clinical Medical Physics

Article Title: Target localization accuracy in frame‐based stereotactic radiosurgery: Comparison between MR‐only and MR/CT co‐registration approaches

doi: 10.1002/acm2.13580

Figure Lengend Snippet: Screenshots of the GammaPlan treatment planning system depicting a transversal magnetic resonance (MR) slice of the irradiated phantom intersecting five Gamma Knife (GK) shots, after performing the spatial co‐registration to the Leksell stereotactic space (LSS), following the (A,B) MR‐only, (C,D) MR/CT, and (E,F) MR‐corrected workflows. To increase visibility, the central GK shot is enlarged in the bottom row panels (B,D,F). Legend: Green solid line: the 14‐Gy isodose for each GK shot delivered (corresponding centroids serving as reference points); light blue, dark blue, and red lines: contours of the automatically generated target structures, defined using the radiation‐induced polymerization areas, for the assessment of target localization accuracy, following the MR‐only, MC/CT, and MR‐corrected workflows, respectively. All data shown are registered to the LSS coordinate system

Article Snippet: The imaged N‐shaped fiducials are identified by the dedicated ELEKTA GammaPlan (ELEKTA AB, Stockholm, Sweden) treatment planning system (TPS) on the primary image stack and an automatic least‐square fitting process (with the mechanically expected shape and size of the fiducials) is performed to determine the most optimum rigid transformation, linking the imaging and treatment coordinate systems.

Techniques: Irradiation, Generated