ESTRO 36 Abstract Book

S101 ESTRO 36 _______________________________________________________________________________________________

management system itself can be introduced. Therefore, registering and analysing errors is an efficient way to improve safety.

NTCP models can be improved by incorporating clinical risk factors into model formulation. Overview of published results will be presented. A further important step is the inclusion of molecular/genetic predictors into NTCP models. This issue is still at a very primitive stage and should be elucidated because, given the same set of clinical/dosimetric factors, patient-to patient variability in normal tissue response to radiation has been widely recognized in clinical practice, suggesting that this phenomenon might be, at least in part, genetically driven. In this presentation data on molecular/genetic markers influencing radio-induced toxicity are presented, together with the first findings supporting the hypothesis that a genetically determined dose–response relationship is possible and could be used to predict the probability of side effects associated with radiotherapy and serve as a rational basis for individualized radiation dose prescriptions. The future lies in these multi-factorial prediction models: a great effort has to be done to collect reliable detailed prospective data for the development of NTCP models with the inclusion of predisposing clinical/genetic features for normal tissues involved in radiotherapy. SP-0198 Particle therapy – how to start up and carry out daily clinical practice H. Hentschel 1 1 EBG MedAustron GmbH, Medical Department, Wiener Neustadt, Austria The MedAustron Center for ionbeam radiotherapy and research started clinical operation, i.e. patient treatment in December 2016. MedAustron does not use any turn-key solutions for beam acceleration, beam delivery, patient positioning and positioning-verification but refined existing products and teamed up with industrial and scientific partners to develop novel solutions. The decision to use non off-the shelf technology and to CE-certify the Synchrotron and affiliated components as medical devices is an opportunity to maximize the usability of the given technical conditions as well as to optimize the efficiency of patient treatment. The team of RTTs which was already integrated in the project phase faced new challenges and demands off the beaten path of existing and settled structures of hospital based radiotherapy departments. The approach of sequentially taking individual beam lines and particle species in operation involves constant change and demands a team of flexible and innovative radiotherapists. MedAustron is an autonomous outpatient clinic which is not affiliated with a hospital. As a consequence RTTs are also involved in regulatory affairs, quality management, risk management, purchase, maintenance and documentation of inspections of medical products and supplies. Teaching Lecture: Particle therapy – how to start up and carry out daily clinical practice

Teaching Lecture: Automated planning, knowledge- based planning and other novel developments in treatment planning - how do they work and perform?

SP-0196 Automated planning, knowledge-based planning and other novelties in treatment planning - how do they work and perform? B. Heijmen 1 , P. Voet 2 , L. Rossi 1 , A. Sharfo 1 , Y. Wang 1 , S. Breedveld 1 1 Erasmus MC Cancer Institute, Radiation Oncology, Rotterdam, The Netherlands 2 Elekta AB, Elekta AB, Stockholm, Sweden This lecture will give an overview of latest developments in treatment planning, both including principles of novel approaches, and applications. More specifically, the following topics will be discussed: - Treatment plan generation as a formal multi-criterial optimization problem - difference between Pareto- optimal plan and clinically optimal plan - Overview of algorithms for automated and knowledge- based plan generation - Validation of the quality of automatically generated plans: how + results - Automated planning for bias-free treatment technique comparisons - Automated planning for adaptive radiotherapy - Future role of planners in the era of automated plan generation - Real-time planning - Beam angle optimization for non-coplanar treatment - Individualized automated plan QA: is the generated plan optimal for the given patient anatomy? - From PTV/PRV towards probabilistic or robust planning SP-0197 Building of NTCP models that contain non- dosimetric parameters T. Rancati 1 1 Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy It is well known that the risk of radio-induced toxicity increases when higher doses and larger volumes are involved in the irradiation and, in the last years, some consistent results have been published on the possible estimation of normal tissue complication probability (NTCP) for a number of organs-at-risk. The widespread method used for such calculations is based on a sigmoid dose-response curve coupled to reduction of the whole dose-volume histogram into one parameter (such as the equivalent uniform dose). NTCP models with their prediction based only on dosimetric variables can be used in treatment planning and can act as a baseline reference. On the other hand, it is becoming clearer that radiation-related side effects are also correlated to a number of patient-related factors. With the advent of newer radiotherapy technologies, which allow steep gradients and minimization of doses to normal tissues, there is an increased interest in understanding clinical/genetic risk factors that might enhance patient radio-sensitivity and to develop NTCP models which might include these variables in order to achieve better normal tissue complication predictions. A number of published studies have shown that current Teaching Lecture: Building of NTCP models that contain non-dosimetric parameters

Teaching Lecture: Three-dimensional cell culture systems

SP-0199 Three-dimensional cell culture systems N. Cordes 1 1 OncoRay - Center for Radiation Research in Oncology, Dresden, Germany 3D cell cultures appear in many different self-made and commercially available facets. A common denominator for some of them is that they enable cell growth in a more