ESTRO 37 Abstract book

S182

ESTRO 37

SP-0360 Our 3 new journals, update after 1 year: ctRO P. Blanchard 1 , D. Zips 2 1 Institut Gustave Roussy, Radiation Oncology, Villejuif, France 2 University of Tuebingen, Radiation Oncology, Tuebingen, Germany Abstract text The first issue of Clinical and Translational Radiation Oncology (ctRO), the newest clinical journal within the ESTRO family, was published in December 2016. It contained an editorial by the editors in chief, and five original articles. Since then, six additional volumes have been compiled and published, representing a total of 52 additional articles and leading to 11,797 articles being downloaded in the first three quarters of 2017. The last published volume contained 14 articles dealing with different aspects of radiation oncology and various tumor sites. Many more articles are being received, reviewed and subsequently published. One of the goals of ctRO, along with its open-access policy, was to have a timely peer-review process and rapid publication, to allow fast and broad dissemination of science. The mean turnaround time between submission and first editorial decision based on the reviewers’ recommendations for research articles is currently close to three weeks. After receiving the revised version, the final decision is reached in less than two days. This shows the efficiency of the reviewing process in place and the dedication of our excellent reviewer community. It is now time to reflect on the first year of ctRO, in terms of achievements, but also and more importantly with respect to the direction we want the journal to follow. SP-0361 Our 3 new journals, update after 1 year: phiRO L. Muren Aarhus University Hospital, Aarhus, Denmark SP-0362 Our 3 new journals, update after 1 year: tipsRO Writing for medical publication: increasing your impact S. Faithfull 1 1 University of Surrey, Faculty of Health and Medical Sciences, Guildford, United Kingdom Abstract text Medical publishing is about communication of research with the aim of changing practice or informing future medical research. Writing for impact is essential to good scientific communication which increases citations and the reading of your paper. Impact occurs when the research generates benefits for health care; radiotherapy treatments, health services or provide economic benefits. Knowledge is intertwined with persuasion and how you write influences impact. Researchers are increasingly expected to be accountable for how their research is used therefore publication is not the end goal, but how that publication informs and changes radiotherapy practice. This presentation explores how best to increase the impact of your writing for the TipsRO journal through use of techniques that increase readership, improve search terms but also help the reader understand how to take forward your ideas. Examples will be presented from the journal to demonstrate how to improve writing for the journal. Abstract not received

PV-0363 The effect of the use of CPAP on set-up errors in SBRT treatments in the thorax T. Katzman 1 , Z. Symon 1 , I. Weiss 1 , Y. Lawrence 2 1 Sheba Medical Center, radiation Oncology, Ramat-Gan, Israel 2 Sheba Medical Center, Center for Translational Research in Radiation Oncology, Ramat-Gan, Israel Purpose or Objective Over the last few years our centre has pioneered the use of continuous positive airway pressure (CPAP) for the treatment of thoracic tumours. We previously demonstrated that, compared with free-breathing, the use of CPAP increased total lung volume, while decreasing tumour movement leading to a considerable dosimetric advantage. A constant PTV expansion was applied to all cases. The decision of whether to use CPAP or standard free-breathing was based upon physician preference, but was the preferred option for lower lung tumours and those with multiple intrathoracic targets. The purpose of this study is to analyse whether the use of CPAP impacted upon the reproducibility of patient set- up. We hypothesised that the systematic and random errors would be reduced through use of CPAP, permitting use of a smaller PTV margin. Material and Methods 30 courses of SBRT treatments in the thorax were selected – 15 treated with CPAP, and 15 treated without CPAP. All patients were positioned similarly with a chest- board, and knee immobilization. Abdominal pressure was used when it was found to be effective for patients treated without CPAP. Altogether, 130 cone-beam CT (CBCT) scans performed prior to each treatment were analysed. Translational moves in the RL, AP, and SI planes were recorded. The systematic and random errors for each plane were evaluated, and the resulting PTV margin size using van Herk's recipe was calculated. Resulting PTV volumes were calculated using the standard ellipsoid formula. Results The mean (±standard deviation) of the set-up translational movements for the non-CPAP treatments were 0.4(±0.4) cm, 0.6(±0.4) cm, 0.7(±0.3) cm in the RL, AP and SI planes respectively. The mean (±standard deviation) of the set-ups for the CPAP treatments were 0.5(±0.4) cm, 0.4(±0.4) cm, 0.5(±0.5) cm in the RL, AP and SI planes respectively (all NS for comparison with CPAP). The PTV margins required in the non-CPAP arm were 1.3, 1.8 and 2 cm in the RL, AP and SI planes respectively. The margins required in the CPAP arm were 1.4, 1.3 and 1.6 cm in the RL, AP and SI planes respectively. The resultant CPAP PTV for a 1cm diameter target was 30% smaller than that obtainable without CPAP. Conclusion The use of CPAP increases the set-up reproducibility in the AP and SI directions, and slightly decreases the set-up reproducibility in the RL direction, although these differences were not statistically significant. Although the differences in each dimension were small, the overall difference in PTV volume was considerable, further improving the dosimetric advantages of CPAP use in thoracic tumours. PV-0364 The correlation between rotations of the pelvis and geometrical inaccuracy of the para-aortic region E. Ajanovic 1 , M. Kamphuis 1 , M.A.J. De Jong 1 , G.H. Westerveld 1 , J. Visser 1 , N. Van Wieringen 1 1 Academic Medical Center, Radiotherapie, Amsterdam, The Netherlands

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