Andrea Schwahofer

Learn More
PURPOSE To investigate treatment outcome in patients suffering from sacral chordoma after intensity modulated radiotherapy (IMRT) for primary versus recurrent disease. MATERIAL/METHODS We report on 34 patients with histologically proven sacral chordoma. Seventeen patients were treated at time of initial diagnosis with post-operative IMRT (n=13) or with(More)
To investigate how segmented multileaf modulation-(sMLM-)based intensity-modulated radiotherapy (IMRT) and dynamic helical tomotherapy (ToTh) affect the peripheral dose (PD) outside the treated region. A cuboid Perspex phantom was scanned in a computed tomograph. Different artificial cases were contoured consisting of OARs surrounded by cylindrically shaped(More)
The aim of this study has been the experimental determination of the energy dependent dose-to-water response of TLD600 and TLD700 thermoluminescent detectors (Harshaw) in X-ray beams with mean photon energies from about 20 to 200keV in comparison with 60Co gamma rays and 6MV X-rays. Experiments were carried out in collaboration with the German secondary(More)
Metal artifacts in computed tomography CT images are one of the main problems in radiation oncology as they introduce uncertainties to target and organ at risk delineation as well as dose calculation. This study is devoted to metal artifact reduction (MAR) based on the monoenergetic extrapolation of a dual energy CT (DECT) dataset. In a phantom study the CT(More)
The goal of this work was to compare different methods of incorporating the additional dose of mega-voltage cone-beam CT (MV-CBCT) for image-guided intensity modulated radiotherapy (IMRT) of different tumor entities. The absolute dose delivered by the MV-CBCT was calculated and considered by creating a scaled IMRT plan (scIMRT) by renormalizing the(More)
PURPOSE To present a modified Winston-Lutz-Test procedure able to measure beam and laser angles. METHODS Room lasers have not only to indicate the isocenter spot but should also be aligned to the central beam axis. Therefore a modified WL test, based on a cube phantom made of low density foam material was developed. The classical steel sphere in the(More)
BACKGROUND To report our long-term results with postoperative intensity-modulated radiation therapy (IMRT) in patients suffering from squamous-cell carcinoma (SCC) of the oral cavity or oropharynx. METHODS Seventy five patients were retrospectively analyzed. Median age was 58 years and 84 % were male. 76 % of the primaries were located in the oropharynx.(More)
  • 1