ESTRO 36 Abstract Book

S307 ESTRO 36 _______________________________________________________________________________________________

as previous abdominal/pelvic surgery and pre-existing disease of the colon. Although much has still to be explored, bowel dose-volume effects were better quantified in recent studies showing correlation between the bowel DVH in pelvic IMRT and acute loose stools/diarrhea. The long-term effects of the inflammatory response of the bowel after RT are the object of a number of on-going trials with a careful evaluation of their impact on quality-of-life, largely underestimated in the past. The assessment of reliable predictive models of urinary toxicity is challenging, and this reflected in a heavy lack of knowledge of bladder dose-volume effects, well described by Quantec. Fortunately, major advances occurred in the last years thanks to few prospective trials, including patient- reported scoring of urinary symptoms. One of the most outstanding findings is the assessment of the existence of a dose-volume effect for several urinary symptoms typically occurring after RT for PCa. Predominantly, reducing the bladder volume receiving >75-78Gy or >8- 12Gy/week (in the case of acute toxicity) may reduce acute and/or late urinary toxicity. Importantly, the impact of the (prescribed and/or maximum) dose was also confirmed in several studies both in radical and post- prostatectomy settings. Few studies also reported that the bladder trigone is more sensitive: based on these results, a value for trigone Dmax<78-80 Gy may be suggested. Many studies identified clinical factors that are correlated with urinary toxicity: the most important one is the baseline urinary functionality, which clearly modulates the response of the bladder and urethra to RT. Other major predictors are vascular problems, use of anti- hypertensives, previous transurethral resection of the prostate; interestingly, neo-adjuvant/adjuvant hormone therapy was found to be protective with respect to the onset of severe acute patient-reported symptoms: this remarkable result surely needs to be confirmed. Confirmations regarding the consequential nature of late urinary toxicity appeared, suggesting that a fraction of the late events are a “consequence” of the exuberant repair process subsequent to the acute inflammatory phase. Then, any effort to reduce acute toxicity may impact the occurrence of late events. NTCP models for haematological toxicity including dose-volume patterns of pelvic marrow were recently reported for both pts treated with radio-chemotherapy for rectal/gynecological cancer and for pts treated for PCa with RT only. NTCP models regarding sexual dysfunctions remain scarce, although the increased use of patient-reported and/or objective scores promises to get new results in the near future. As an example, the evidence that the sparing of penile bulb and the baseline erectile functionality are correlated with the insurgence of impotence in hormone-naïve pts, potent before RT for PCa, was recently reported. The continuous improvement of NTCP models in the pelvic area includes the impact of hypo-fractionation, especially for bladder: a much higher sensitivity to fractionation compared to what expected if applying the LQ-model (and alpha/beta values between 3 and 5) has been reported and modeled for several late end-points. Although relevant progresses occurred in the field, much remains to be investigated. Interestingly, the need of integrating dose-volume effects into multi-variable models including clinical (and genetic) parameters is nowadays very clear, showing that the dose distribution is only one (highly relevant) piece of the picture. Particular attention should be dedicated to the generalizability of integrated NTCP models through external validations, testing models on new data/pts/situations. First validations of NTCP models of rectal and urinary toxicity appeared in the last years, opening a pioneering, relevant field of investigation for NTCP modeling.

Symposium: RT is technology driven. How to keep the patient involved?

SP-0580 Patient education – tools to improve patient positioning H. Hansen 1 1 Aarhus University Hospital, The Danish Centre for Particle Therapy, Aarhus N, Denmark It is well-known that informing patients with cancer about treatment can help relieve anxiety. Studies in radiotherapy have focused on the use of tools in patient education. This includes the use of visual aids and exercises to facilitate knowledge about radiotherapy treatments. Use of visual aids includes the use of videos, virtual reality programmes as well as other computer programmes. A combination of virtual reality programmes and exercises has been tested in different areas as tools in rehabilitation and treatment. In our radiotherapy department, we tested a combination of exercises and 3D as means to teach patients about positioning. We hoped to reduce the residual rotational set-up errors and the number of repositions. We also wanted to improve patients sense of control by increasing self-efficacy and thus reducing distress. Bandura describes self-efficacy as believing in own capability to react to specific conditions in the environment. Knowledge of and believe in being able to control a given situation can, according to Bandura, increase belief in self-efficacy. Self-efficacy has been linked to quality of life and mood in cancer care. In our study patients were randomised to either standard care (control group) or standard care and a teaching session combining practical exercises and 3D images (intervention group). Off-line evaluation of daily images showed a reduction of residual rotational set-up errors in the intervention group compared to the control group. No differences were found in number of repositionings, distress score or self-efficacy. It was concluded that it is possible to use teaching sessions as a method to improve positioning in patients undergoing radiotherapy. Furthermore, it was concluded that teaching the patients did not seem to affect distress score or self-efficacy neither at baseline nor at the end of treatment. SP-0581 Public knowledge of RT saves lives: the case for RT awareness E. Naessens Dublin, Ireland There can be little doubt that well-structured communications between patients and healthcare professionals save time, cost, reduce risk, increase patient confidence in treatment, uncover false beliefs and misconceptions, and offer valuable insights and data into health services. Drawing upon his experience as an oncology patient, role as a patient advocate, and academic training in Mental and Moral Science, Eddie Naessens makes the case that robust healthcare communications strategies are pragmatic and essential to best practice. Oncology patients rely significantly on the quality of information and communications offered. He sets out psychological and cognitive science approaches to communications that should be considered in the design of PROMs in the RT setting. SP-0582 PROMs analysis to improve communication and enhance practice A. Lemanska 1 1 University of Surrey, School of Health Sciences, Guildford, United Kingdom PROMs add an important dimension to the information gathered by professional assessments or clinical tests. The