The investigated patients are expected to benefit from this study, since in case of detected deviations between planned and actual treatment delivery a proper correction could be applied in the next irradiation fraction, assuring an overall better treatment than without any monitoring. Moreover, site-specific patient-population information on the ion range precision at HIT might enable improvement of the CT-range calibration curve as well as safe reduction of the treatment margins to promote enhanced treatment plan conformality for full clinical exploitation of the promises of ion beam therapy.