Abstract Book

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has to be made. Secondly, the clinician should explain which options are available; thirdly, the clinician should try to elicit patient preferences and values, and finally patient and clinician’s preferences should be integrated into a shared decision. Unfortunately, even clinicians aware of SDM, usually do apply steps 1 and 2, but often omit step 3 and 4, leaving the patient alone with a difficult choice. Next to the teaching of clinicians, tools such as patient decision aids (PtDA) can be very helpful, to stimulate that each patient receives the same objective information. To build a good PtDA, it is recommended to follow the IPDAS roadmap [www.ipdas.ohri.ca, Elwyn et al, 2009]. One of the most important aspects in this roadmap is to involve patients at almost each step. Most PtDAs in radiotherapy will contain information on both side effects and effects on local control and survival. Patients should be involved e.g. to decide which side effects are most important to mention, and to choose how to visualize difficult terms as percentages etc. Until now, PtDAs are fairly general, and do not yet contain very individualized information. Therefore, in the current area of big data, several initiatives are ongoing to develop prognostic models to estimate the effect of a certain treatment on outcome, and to incorporate these models in the patient decision aids. Most clinicians are only willing to change their current clinical practice if 1) the is clinical evidence that SDM really is beneficial, and 2) if it fits the clinical care path. Therefore, clinicians should be involved early in projects aimed to implement SDM. Conclusion There is an increasing amount of evidence that SDM improves quality of care. Since implementation is still quite scarce, several strategies are currently being developed to increase implementation of SDM. SP-0009 Evidence for partial organ treatments R. Laing 1 1 Royal Surrey NHS Trust, Oncology, Guildford, United Kingdom Abstract text Partial organ treatment has been extensively investigated in breast cancer with over 18,000 patients randomised in 8 large trials. Whilst different techniques and patient selection were employed encouraging early results have been reported using different treatment techniques. The evidence in Prostate Cancer is much more limited with relatively little data with small patient numbers using a range of methods ranging from hemi-gland brachytherapy to ultra-focal treatments. This talk will describe the definitions used in partial organ treatments and the emerging data in Prostate Cancer as well as a brief summary of the current situation in Breast Cancer. SP-0010 Variation in dose distribution by different radiation modalities D. Georg 1 1 Medizinische Universität Wien, Division Medical Radiation Physics- Department of Radiation Oncology, Vienna, Austria Abstract text Partial organ irradiation has the potential to minimize late radiation effects, especially in light of the enormous technological progress made during the last decades. More specifically, computerized treatment plan optimi- zation and image guided beam delivery of external beam Symposium: Partial organ treatments to minimise late radiation effects

Teaching Lecture: Patient involvement and shared decision making

SP-0008 Patient involvement and shared decision making Abstract by: L. Boersma 1 1 MAASTRO Clinic, Radiation Oncology, Maastricht, The Netherlands

Speaker: C. Van Audenhove KU Leuve, Leuven, Belgium

Introduction After the introduction of evidence based medicine, patient involvement in decision-making is becoming increasingly important. The problem is that this development suffers from lack of implementation. Shared Decision Making (SDM) is the approach that most patients desire, and although clinicians may feel that they are already sharing decisions, evidence shows that they are not [Coulter 2011, Légaré 2012, Mulley 2012]. What is SDM, why, and how to measure its effect? SDM is about the health care provider eliciting patients’ needs and preferences, and deliberating together with the patient in order to make a decision about management. SDM is important in so-called preference- sensitive decisions where trade-offs exist between options that depend on patient preferences. Individuals may value treatment options differently in terms of effect sizes, treatment burden or side effects. The ultimate goal is that the patient undergoes that treatment that suits his or her preferences and values best. It is however extremely difficult to measure this goal. Therefore, quite often the decisional conflict scale is used to measure SDM. Other approaches to quantify SDM aim at measuring the process of SDM, such as the SDM-Q-9 or the OPTION scale. In spite of these measure- problems, evidence for beneficial effects of SDM is cumulating. There is e.g. level I evidence that patient decision aids (ptDAs)– either used within or outside the medical consultation - reduce decisional conflict and improve users’ knowledge and accuracy of perceived risks. This results in realistic expectations and satisfaction with their decision and the decision making process [Stacey 2014]. It also reveals that patients show a tendency to choose more conservatively compared to doctors, especially in case of elective surgery. There is insufficient evidence, yet, that this leads to overall cost savings [Walsh 2014]. For the time being PtDAs can be looked upon as effective approaches that improve the outcomes of patient encounters with their clinicians at acceptable costs [Katz 2014]. Facilitators and barriers One of the most often quoted barriers for SDM is that many clinicians think that patients are not able to make these difficult decisions, or do not want to be involved. Another often-mentioned barrier is that it increases consultation time, for which no reimbursement is foreseen. Moreover, if SDM indeed leads to less treatment, the clinician will lose revenues. Lack of skills to to perform SDM in clinical practice is another potential barrier. Higher patient satisfaction is the most natural facilitator; in addition, to stimulate implementation of SDM in daily clinical practice, it is essential that the whole SDM process nicely fits into the standard clinical care-path. How to improve implementation of SDM in clinical practice? A pre-requisite for implementation of SDM in clinical practice, is that clinicians are skilled to apply SDM. For this purpose, training modules are currently being developed. In short, four steps can be discriminated: The first step in SDM is to make patients aware that a choice