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BACKGROUND The purpose of the study was the clinical implementation of a kV cone beam CT (CBCT) for setup correction in radiotherapy. PATIENTS AND METHODS For evaluation of the setup correction workflow, six tumor patients (lung cancer, sacral chordoma, head-and-neck and paraspinal tumor, and two prostate cancer patients) were selected. All patients were(More)
   Intra-procedural acquisition of the patient anatomy is a key technique in the context of computer-assisted interventions (CAI). Ultrasound (US) offers major advantages as an interventional imaging modality because it is real time and low cost and does not expose the patient or physician to harmful radiation. To advance US-related research, the purpose of(More)
One of the main challenges related to electromagnetic tracking in the clinical setting is a placement of the field generator (FG) that optimizes the reliability and accuracy of sensor localization. Recently, a new mobile FG for the NDI Aurora® tracking system has been presented. This Compact FG is the first FG that can be attached directly to an ultrasound(More)
Image registration has many medical applications in diagnosis, therapy planning and therapy. Especially for time-adaptive radiotherapy, an efficient and accurate elastic registration of images acquired for treatment planning, and at the time of the actual treatment, is highly desirable. Therefore, we developed a fully automatic and fast block matching(More)
Modern techniques of radiotherapy like intensity modulated radiation therapy (IMRT) make it possible to deliver high dose to tumors of different irregular shapes at the same time sparing surrounding healthy tissue. However, internal tumor motion makes precise calculation of the delivered dose distribution challenging. This makes analysis of tumor motion(More)
Respiratory motion limits the potential of modern high-precision radiotherapy techniques such as IMRT and particle therapy. Due to the uncertainty of tumour localization, the ability of achieving dose conformation often cannot be exploited sufficiently, especially in the case of lung tumours. Various methods have been proposed to track the position of(More)
The intraoperative shift of neuroanatomical landmarks that serve as reference points is an unsolved problem in current neuronavigation. Monitoring the position of these landmarks requires repeated intraoperative imaging. We analyzed the effectiveness of a 3-D ultrasound system for imaging through a bore-hole trepanation. A tissue-mimicking ultrasound(More)
BACKGROUND AND PURPOSE Proton therapy for uveal melanoma provides high-conformal dose application to the target volume and, thus, an optimal saving of the organs at risk nearby. Treatment planning is done with the model-based treatment-planning system EYEPLAN. Tumor reconstruction is based only on a fundus composite, which often leads to an overestimation(More)