Particle beam treatment allows accurate dose delivery ontocarcinogen tissue. The reachable accuracy is limited by patient alignmenterrors relative to the beam source. Errors can be corrected manuallyor byautomatic comparison of two X-ray images to a CT-scan but correctionmostly does not cover all degrees of freedom (DoF). In this contributionwe present a solution that makes use of one X-ray image and computesfull 6 DoF alignment correction by gray value based comparison toaCT. By using regions of interest, we are able to increase performanceand reliability.s
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