@article{BratengeierHolubyev2016,
  author    = {Bratengeier, Klaus and Holubyev, Kostyantyn},
  title     = {Anisotropy of dose contributions-an instrument to upgrade real time IMRT and VMAT adaptation?},
  series = {Medical Physics},
  volume    = {43},
  journal   = {Medical Physics},
  number    = {11},
  doi       = {10.1118/1.4963806},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186833},
  pages     = {5826-5834},
  year      = {2016},
  abstract  = {Purpose: To suggest a definition of dose deposition anisotropy for the purpose of ad hoc adaptation of intensity modulated arc therapy (IMRT) and volumetric arc therapy (VMAT), particularly in the vicinity of important organs at risk (OAR), also for large deformations. Methods: Beam's-eye-view (BEV) based fluence warping is a standard adaptation method with disadvantages for strongly varying OAR shapes. 2-Step-adaptation overcomes these difficulties by a deeper analysis of the 3D properties of adaptation processes, but requires separate arcs for every OAR to spare, which makes it impractical for cases with multiple OARs. The authors aim to extend the 2-Step method to arbitrary intensity modulated plan by analyzing the anisotropy of dose contributions. Anisotropy was defined as a second term of Fourier transformation of gantry angle dependent dose contributions. For a cylindrical planning target volume (PTV) surrounding an OAR of varying diameter, the anisotropy and the dose-normalized anisotropy were analyzed for several scenarios of optimized fluence distributions. 2-Step adaptation to decreasing and increasing OAR diameter was performed, and compared to a usual fluence based adaptation method. For two clinical cases, prostate and neck, the VMAT was generated and the behavior of anisotropy was qualitatively explored for deformed organs at risk. \# Results: Dose contribution anisotropy in the PTV peaks around nearby OARs. The thickness of the "anisotropy wall" around OAR increases for increasing OAR radius, as also does the width of 2-Step dose saturating fluence peak adjacent to the OAR K. Bratengeier et al., "A comparison between 2-Step IMRT and conventional IMRT planning," Radiother. Oncol. 84, 298-306 (2007)]. Different optimized beam fluence profiles resulted in comparable radial dependence of normalized anisotropy. As predicted, even for patient cases, anisotropy was inflated even more than increasing diameters of OAR. Conclusions: For cylindrically symmetric cases, the dose distribution anisotropy defined in the present work implicitly contains adaptation-relevant information about 3D relationships between PTV and OAR and degree of OAR sparing. For more complex realistic cases, it shows the predicted behavior qualitatively. The authors claim to have found a first component for advancing a 2-Step adaptation to a universal adaptation algorithm based on the BEV projection of the dose anisotropy. Further planning studies to explore the potential of anisotropy for adaptation algorithms using phantoms and clinical cases of differing complexity will follow.},
  language  = {en}
}
@article{RichterPolatLawrenzetal.2016,
  author    = {Richter, Anne and Polat, B{\"u}lent and Lawrenz, Ingulf and Weick, Stefan and Sauer, Otto and Flentje, Michael and Mantel, Frederick},
  title     = {Initial results for patient setup verification using transperineal ultrasound and cone beam CT in external beam radiation therapy of prostate cancer},
  series = {Radiation Oncology},
  volume    = {11},
  journal   = {Radiation Oncology},
  number    = {147},
  doi       = {10.1186/s13014-016-0722-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147677},
  year      = {2016},
  abstract  = {Evaluation of set up error detection by a transperineal ultrasound in comparison with a cone beam CT (CBCT) based system in external beam radiation therapy (EBRT) of prostate cancer. Methods: Setup verification was performed with transperineal ultrasound (TPUS) and CBCT for 10 patients treated with EBRT for prostate cancer. In total, 150 ultrasound and CBCT scans were acquired in rapid succession and analyzed for setup errors. The deviation between setup errors of the two modalities was evaluated separately for each dimension. Results: A moderate correlation in lateral, vertical and longitudinal direction was observed comparing the setup errors. Mean differences between TPUS and CBCT were (-2.7 ± 2.3) mm, (3.0 ± 2.4) mm and (3.2 ± 2.7) mm in lateral, vertical and longitudinal direction, respectively. The mean Euclidean difference between TPUS and CBCT was (6.0 ± 3.1) mm. Differences up to 19.2 mm were observed between the two imaging modalities. Discrepancies between TPUS and CBCT of at least 5 mm occurred in 58 \% of monitored treatment sessions. Conclusion: Setup differences between TPUS and CBCT are 6 mm on average. Although the correlation of the setup errors determined by the two different image modalities is rather week, the combination of setup verification by CBCT and intrafraction motion monitoring by TPUS imaging can use the benefits of both imaging modalities.},
  language  = {en}
}
@article{ToussaintRichterManteletal.2016,
  author    = {Toussaint, Andr{\´e} and Richter, Anne and Mantel, Frederick and Flickinger, John C. and Grills, Inga Siiner and Tyagi, Neelam and Sahgal, Arjun and Letourneau, Daniel and Sheehan, Jason P. and Schlesinger, David J. and Gerszten, Peter Carlos and Guckenberger, Matthias},
  title     = {Variability in spine radiosurgery treatment planning - results of an international multi-institutional study},
  series = {Radiation Oncology},
  volume    = {11},
  journal   = {Radiation Oncology},
  number    = {57},
  doi       = {10.1186/s13014-016-0631-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146687},
  year      = {2016},
  abstract  = {Background The aim of this study was to quantify the variability in spinal radiosurgery (SRS) planning practices between five international institutions, all member of the Elekta Spine Radiosurgery Research Consortium. Methods Four institutions provided one representative patient case each consisting of the medical history, CT and MR imaging. A step-wise planning approach was used where, after each planning step a consensus was generated that formed the basis for the next planning step. This allowed independent analysis of all planning steps of CT-MR image registration, GTV definition, CTV definition, PTV definition and SRS treatment planning. In addition, each institution generated one additional SRS plan for each case based on intra-institutional image registration and contouring, independent of consensus results. Results Averaged over the four cases, image registration variability ranged between translational 1.1 mm and 2.4 mm and rotational 1.1° and 2.0° in all three directions. GTV delineation variability was 1.5 mm in axial and 1.6 mm in longitudinal direction averaged for the four cases. CTV delineation variability was 0.8 mm in axial and 1.2 mm in longitudinal direction. CTV-to-PTV margins ranged between 0 mm and 2 mm according to institutional protocol. Delineation variability was 1 mm in axial directions for the spinal cord. Average PTV coverage for a single fraction18 Gy prescription was 87 ± 5 \%; Dmin to the PTV was 7.5 ± 1.8 Gy averaged over all cases and institutions. Average Dmax to the PRV_SC (spinal cord + 1 mm) was 10.5 ± 1.6 Gy and the average Paddick conformity index was 0.69 ± 0.06. Conclusions Results of this study reflect the variability in current practice of spine radiosurgery in large and highly experienced academic centers. Despite close methodical agreement in the daily workflow, clinically significant variability in all steps of the treatment planning process was demonstrated. This may translate into differences in patient clinical outcome and highlights the need for consensus and established delineation and planning criteria.},
  language  = {en}
}
@article{DjuzenovaFiedlerKatzeretal.2016,
  author    = {Djuzenova, Cholpon S. and Fiedler, Vanessa and Katzer, Astrid and Michel, Konstanze and Deckert, Stefanie and Zimmermann, Heiko and Sukhorukov, Vladimir L. and Flentje, Michael},
  title     = {Dual PI3K-and mTOR-inhibitor PI-103 can either enhance or reduce the radiosensitizing effect of the Hsp90 inhibitor NVP-AUY922 in tumor cells: The role of drug-irradiation schedule},
  series = {Oncotarget},
  volume    = {7},
  journal   = {Oncotarget},
  number    = {25},
  doi       = {10.18632/oncotarget.9501},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177770},
  pages     = {38191-38209},
  year      = {2016},
  abstract  = {Inhibition of Hsp90 can increase the radiosensitivity of tumor cells. However, inhibition of Hsp90 alone induces the anti-apoptotic Hsp70 and thereby decreases radiosensitivity. Therefore, preventing Hsp70 induction can be a promising strategy for radiosensitization. PI-103, an inhibitor of PI3K and mTOR, has previously been shown to suppress the up-regulation of Hsp70. Here, we explore the impact of combining PI-103 with the Hsp90 inhibitor NVP-AUY922 in irradiated glioblastoma and colon carcinoma cells. We analyzed the cellular response to drug-irradiation treatments by colony-forming assay, expression of several marker proteins, cell cycle progression and induction/repair of DNA damage. Although PI-103, given 24 h prior to irradiation, slightly suppressed the NVP-AUY922-mediated up-regulation of Hsp70, it did not cause radiosensitization and even diminished the radiosensitizing effect of NVP-AUY922. This result can be explained by the activation of PI3K and ERK pathways along with G1-arrest at the time of irradiation. In sharp contrast, PI-103 not only exerted a radiosensitizing effect but also strongly enhanced the radiosensitization by NVP-AUY922 when both inhibitors were added 3 h before irradiation and kept in culture for 24 h. Possible reasons for the observed radiosensitization under this drug-irradiation schedule may be a down-regulation of PI3K and ERK pathways during or directly after irradiation, increased residual DNA damage and strong G2/M arrest 24 h thereafter. We conclude that duration of drug treatment before irradiation plays a key role in the concomitant targeting of PI3K/mTOR and Hsp90 in tumor cells.},
  language  = {en}
}
@phdthesis{Sauter2016,
  author    = {Sauter, Cornelia},
  title     = {Ern{\"a}hrungstherapeutische Maßnahmen auf einer Palliativstation},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173939},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {Ern{\"a}hrungsprobleme haben eine hohe Pr{\"a}valenz auf Palliativstationen und ihre Bedeutung f{\"u}r die Lebensqualit{\"a}t ist nicht zu untersch{\"a}tzen. Die Behandlung wird im Rahmen der fr{\"u}hen palliativmedizinischen Betreuung wichtiger. In der vorliegenden Arbeit wurden verschiedene Screeningtools auf ihre Leistungsf{\"a}higkeit im Setting der Palliativstation {\"u}berpr{\"u}ft, sowie der Bedarf und die Auswirkungen ern{\"a}hrungstherapeutischer Interventionen evaluiert. Im Zeitraum Mai 2011 bis Juli 2012 wurden 125 station{\"a}re Patienten in die Studie eingeschlossen (46,9 \% der in diesem Zeitraum station{\"a}r behandelten Patienten). Ern{\"a}hrungsstatus, Ern{\"a}hrungsprobleme und subjektive Bewertung wurden bei Aufnahme und Entlassung erfragt. Das Mangelern{\"a}hrungsrisiko wurde bei Aufnahme mit drei etablierten Screeningb{\"o}gen vergleichend erfasst (NRS 2002, AKE und SGA) und abschließend bewertet. 64 \% der Patienten gaben bei der station{\"a}ren Aufnahme Ern{\"a}hrungs- und Verdauungsprobleme an. Ein Risiko f{\"u}r eine Mangelern{\"a}hrung lag bei ca. 74 \% der Patienten vor, im Wesentlichen {\"u}bereinstimmend nach AKE, SGA und NRS 2002 (73 \%, 75 \%, 74 \%). Gem{\"a}ß Arzteinsch{\"a}tzung nach klinischer Erstuntersuchung zeigten 72 \% der Patienten einen Bedarf an ern{\"a}hrungstherapeutischen Interventionen. Nach dem AKE waren 58 \% der Patienten manifest mangelern{\"a}hrt, nach DGEM-Kriterien 60 \%. Von 94 Patienten liegen Erst- und Zweitbefragung vor Entlassung vor (75,2 \%). Im Vergleich zur Aufnahme zeigte sich eine signifikante Minderung der Appetitlosigkeit und ein Zugewinn an Genuss bei den nach AKE prim{\"a}r mangelern{\"a}hrten und bei den Patienten mit einer oralen Nahrungsaufnahme von weniger als 50 \% im Vergleich zur Nahrungsaufnahme vor Erkrankungsbeginn. Im pr{\"a}-post-Vergleich verbesserte sich die Lebensqualit{\"a}t signifikant.},
  subject      = {Palliativmedizin},
  language  = {de}
}
@article{ColvillBoothNilletal.2016,
  author    = {Colvill, Emma and Booth, Jeremy and Nill, Simeon and Fast, Martin and Bedford, James and Oelfke, Uwe and Nakamura, Mitsuhiro and Poulsen, Per and Worm, Esben and Hansen, Rune and Ravkilde, Thomas and Rydh{\"o}g, Jonas Scherman and Pommer, Tobias and af Rosenschold, Per Munck and Lang, Stephanie and Guckenberger, Matthias and Groh, Christian and Herrmann, Christian and Verellen, Dirk and Poels, Kenneth and Wang, Lei and Hadsell, Michael and Sothmann, Thilo and Blanck, Oliver and Keall, Paul},
  title     = {A dosimetric comparison of real-time adaptive and non-adaptive radiotherapy: a multi-institutional study encompassing robotic, gimbaled, multileaf collimator and couch tracking},
  series = {Radiotherapy and Oncology},
  volume    = {119},
  journal   = {Radiotherapy and Oncology},
  number    = {1},
  doi       = {10.1016/j.radonc.2016.03.006},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189605},
  pages     = {159-165},
  year      = {2016},
  abstract  = {Purpose: A study of real-time adaptive radiotherapy systems was performed to test the hypothesis that, across delivery systems and institutions, the dosimetric accuracy is improved with adaptive treatments over non-adaptive radiotherapy in the presence of patient-measured tumor motion. Methods and materials: Ten institutions with robotic(2), gimbaled(2), MLC(4) or couch tracking(2) used common materials including CT and structure sets, motion traces and planning protocols to create a lung and a prostate plan. For each motion trace, the plan was delivered twice to a moving dosimeter; with and without real-time adaptation. Each measurement was compared to a static measurement and the percentage of failed points for gamma-tests recorded. Results: For all lung traces all measurement sets show improved dose accuracy with a mean 2\%/2 mm gamma-fail rate of 1.6\% with adaptation and 15.2\% without adaptation (p < 0.001). For all prostate the mean 2\%/2 mm gamma-fail rate was 1.4\% with adaptation and 17.3\% without adaptation (p < 0.001). The difference between the four systems was small with an average 2\%/2 mm gamma-fail rate of <3\% for all systems with adaptation for lung and prostate. Conclusions: The investigated systems all accounted for realistic tumor motion accurately and performed to a similar high standard, with real-time adaptation significantly outperforming non-adaptive delivery methods.},
  language  = {en}
}