Therapeutic dose application by highly tumor-conformal scanned ion beam radiation therapy is currently in most cases not possible for indications which exhibit tumor motion. Due to interference effects, the dose application is likely to be distorted so that treatment is not safely possible. Distorted dose profiles can be improved by means of statistical averaging - the corresponding technique is known as re-scanning and was investigated in this work. Carbon ion treatment planning studies for five lung cancer cases and six different re-scanning flavors were performed. The data show that at least the techniques breath-sampled and random-time- delay re-scanning should be able to compensate dose inhomogeneities sufficiently as to enable patient treatment. Re-scanning was technically implemented in a research version. Experiments were performed to test the implementation, to verify the dose application and to investigate the motion mitigation efficiency. The corresponding dose levels showed only small deviations compared to the therapy delivery mode for stationary targets. The experimental data for motion mitigation strengthened the findings of the simulations. Over- and underdosage can be efficiently reduced using re-scanning.