ESTRO 36 Abstract Book

S303

ESTRO 36 2017

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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

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

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

patient's perspective provides a holistic and a more

comprehensive assessment of treatment, and PROMs are

increasingly being seen as a way to improve practice by

enhancing communication, improving management of

symptoms associated with disease or treatments, as well