ESTRO 2020 Abstract Book

S358 ESTRO 2020

SP-0645 How to become a department head - RTT perspective I. Lobato 1 1 Hospital Espirito Santo, Radiation Oncology, Évora, Portugal Abstract text Becoming a Radiation oncology department head is the result of perseverance, willingness, and investment. It is mandatory that education plays the main role in your profession, so you can be prepared to face daily challenges you have never been faced with, as a "junior" RTT. One must understand that it is mandatory to spend personal time and economic investment in order to make a difference in a team and that the results will always be for the patients and their caregivers. We must know that we lead a team in a kind of "airline" where we all depend on each other and that our observations, actions and checks are fundamental. Being a head of department is a result of clinical experience and the desire and conviction that one can raise and create new paradigms in approaching the department's treatment performance and organization techniques. It is learning daily and having the ability to listen, envisioning various solutions. It is a "jump" to the unknown responsibility, where you have to work multidisciplinarily, standing, several times, in the crossroad of what is right and what is fair. SP-0646 How to become a department head - Radiobiology perspective A. Chalmers 1 1 Inst. of Cancer Sciences-Univ. Glasgow, Department of Clinical Oncology, Glasgow, United Kingdom Abstract text Disclaimer: I’m a Clinical Oncologist masquerading as a radiobiologist and will mainly be talking about my own experiences, so not all of it will be applicable to ‘true’ radiobiologists. However, I am delighted to have this opportunity to talk to the ESTRO community about the trials, tribulations, joy, heartache, successes, failures and generally rich experience of establishing a radiation biology team at the University of Glasgow. Without giving too much away, the strategies and approaches that have helped have included:

Astronomy - Faculty of Science and Engineering, Manchester, United Kingdom ; 2 The University of Manchester, Division of Molecular & Clinical Cancer Studies- School of Medical Sciences- Faculty of Biology- Medicine and Health, Manchester, United Kingdom Purpose or Objective Contouring variation is one of the largest systematic uncertainties in modern radiotherapy. Many studies have evaluated inter-observer variation in small patient cohorts, yet its effect on clinical outcomes has never been analysed quantitatively. We propose a novel framework to analyse the effect of contouring variation on clinical outcome for a large cohort of patients. Material and Methods Planning CTs and contours of 232 intermediate- and high- risk prostate cancer patients, treated with 19x3Gy, were used in this study. For each patient, we compared the manually delineated CTV (prostate gland without seminal vesicles), to an automatically generated CTV contour created using the Deep Learning segmentation tool in ADMIRE v3.0 (Elekta AB, Sweden). This automatic contour can be seen as a consistent (yet imperfect) reference contour created by a virtual observer. Local contour deviation was measured from the reference to the manual contour using spherical coordinates. We sampled the coronal and transverse angles every 3 o , and created contour deviation maps of 60x120 pixels for each patient (Fig. 1). For each pixel, time to biochemical recurrence was modelled using a Cox proportional hazards model accounting for contour deviation, patient age, Gleason score and treated CTV volume (the last three variables were constant for all pixels for a single patient). By assembling the hazard ratios (HR) of the 7200 Cox models in the 60x120 grid, HR maps for each variable were created, and regions of significance were found using permutation testing (permuting contour deviation maps 10^5 times, using the extreme -value as summary statistic).

1) Collaboration 2) Collaboration 3) Collaboration 4) Teamwork 5) Persistence 6) Staying calm 7) Staying focused

I’ll also talk about some other things that have helped, and some things that I wish I hadn’t done.

Poster Highlights: Poster highlights 21 PH: Predictive modelling

PH-0647 The effect of contouring variation on biochemical recurrence following prostate radiotherapy T. Soares Mullen 1 , A. Jenkins 1 , C. Johnson-Hart 2 , A. Green 2 , A. McWilliam 2 , M. Aznar 2 , M. Van Herk 2 , E.M. Vasquez Osorio 2 1 The University of Manchester, School of Physics &

Results Fig. 2 shows the HR map for contour deviation and high significance regions (p<0.001). There is a reduced risk of