ESTRO 37 Abstract book

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ESTRO 37

Personalised treatment and shared decision making in lung SBRT Follow-up and recurrence detection after lung SBRT

of the EU directive 2013/59/EURATOM on BSS clearly states that the members’ states have to guarantee, for radiotherapy practices, that a risk analysis has to be part of the Quality Management System. This EU directive has to be implemented in EU national legislations on the 6 th February 2018. Most of us will face the need to perform risk management of all Radiotherapy processes in the years to come. Risk management has three main steps; risk analysis, risk evaluation and risk control. On this talk we will focus on prospective risk analysis and evaluation methodologies. Risk analysis will seek for specific potential faults that can cause harm. Then the risk(s) associated with these identified hazardous situations are estimated by giving at least a qualitative scale to the two components of risk: probability and severity. The prospective risk analysis methodologies that have been applied to Radiation Therapy are Failure Mode and Effects Analysis (FMEA) and Risk Matrices. Differences and similarities of both methods will be presented. SEVRRA the software application developed by Foro Iberoamericano de Protección Radiológica is being used by different departments in Spain to perform prospective risk analysis. Examples on the use of this software will also be included in this presentation. Abstract text Intra-cranial radiosurgery (SRS) has quite a long history, and it is a very well-established treatment option for brain metastases from various tumors (as well as for a wide spectrum of benign diseases). Its clinical indications progressively expanded, together with technological improvements and validation in clinical trials. The management of brain metastases is now more challenging than ever, due to the extended survival achievable with systemic therapies for a variety of malignancies, and SRS offers the unique opportunity to treat multiple lesions with negligible toxicity in combination with targeted agents and immunotherapy. In the mid-1990s, SRS concepts were firstly transferred to extra-cranial tumor sites, especially the lung. This so-called stereotactic “body” radiotherapy (SBRT) approach, also known as stereotactic ablative radiotherapy (SABR), was then further developed by several centers worldwide. SBRT can be currently defined as a technique for delivering external beam radiotherapy with a high degree of accuracy to an extra-cranial target, using high doses of irradiation, in 1-8 treatment fractions. Its clinical use for treating lung nodules, starting from small peripheral lesions to larger tumors, and lately close to critical structures, progressively increased hand in hand with technology. Many international scientific societies and networks now consider SBRT as the first line non-surgical treatment option for medically inoperable patients affected with stage I NSCLC, and its indications are rapidly expanding also for lung metastases. SBRT has also been used for treating liver, adrenal, bone and lymph- nodal metastases, with the potential of combining systemic therapies with a multiple-site low-toxicity local therapy approach for oligometastatic patients. Retrospective and few prospective data are in favor of its use with potential benefit on survival, for example for lung and breast cancer, and a window of opportunity is open for the combination with immunomodulatory Teaching Lecture: SBRT/SRS: Indications, side effects, outcomes SP-0442 SBRT/SRS: Indications, side effects, outcomes A.R. Filippi 1 1 University of Torino, Radiation Oncology Department, Torino, Italy

Salvage surgery after lung SBRT Future improvements in lung SBRT

Teaching Lecture: Testis

SP-0439 Testis G. De Meerler KU Leuven, Leuven, Belgium

Abstract not received

Teaching Lecture: The state of affairs with ion RBE models

SP-0440 The state of affairs with ion RBE models A. Mairani 1 1 Heidelberg Ion Therapy Center, Other, Heidelberg, Germany Abstract text The relative biological effectiveness (RBE) for ion beams depends on many factors such as dose level, linear- energy transfer (LET)/energy spectrum, tissue radio- sensitivity, oxygen concentration and biological end- point, etc… In clinical practice, however, for proton beams a general RBE of 1.1 is assumed while for carbon ions two biological models are clinically employed, the Local Effect Model and, more recently, the Microdosimetric Kinetic Model but without differentiating, in general, tumor and healthy normal tissues. Research-oriented phenomenological and biophysical models are additionally available for describing the main RBE dependencies. In this lecture, the general features of these models will be introduced emphasizing the similarities, the peculiarities and the limitations of the various models. SP-0441 Prospective risk analysis: basics and applications to treatment QA N. Jornet 1 1 Hospital de la Santa Creu i Sant Pau, Medical Physics, Barcelona, Spain Abstract text The major advances during the last decade in Radiation Therapy techniques and technologies have changed our working procedures and challenged the current QA paradigm. The current QA paradigm methodology based on a comprehensive set of prescriptive tests on the devices does not any longer address completely the needs of a modern Radiotherapy Department. To reinforce this statement, incident and accident registries show that process failures and not device failures are responsible for around 75% of the reported minor/major incident notifications. Therefore, it is time to work on a new Quality Management Paradigm which should be: Holistic and process-centred, team based, risk based, customized to the clinic workflows and that should aim to rationalise QA efforts to mitigate catastrophic events and monitor and improve quality continuously.Furthermore, Article 63 Teaching Lecture: Prospective risk analysis: basics and applications to treatment QA