Weekly contouring rounds and education movies to improve organ at risk delineation in neuro-oncology
David Hofstede,
The Netherlands
OC-0013
Abstract
Weekly contouring rounds and education movies to improve organ at risk delineation in neuro-oncology
Authors: Dario Di Perri1, David Hofstede1, Alida Postma2, Catharina ML Zegers1, Lieke In’t Ven1, Frank Hoebers1, Wouter van Elmpt1, Lindsey Verheesen1, Hilde Beurskens1, Esther GC Troost3, Inge Compter1, Danielle BP Eekers1
1Department of Radiation Oncology (Maastro), Maastricht University Medical Center+, GROW School for Oncology, Maastricht, the Netherlands., -, Maastricht, The Netherlands; 2Department of Radiology and Nuclear Medicine MUMC+, Maastricht, The Netherlands , -, Maastricht, The Netherlands; 3Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany , -, Dresden, Germany
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Purpose or Objective
Accurate and uniform contouring of organs at risk (OARs) is essential to optimise the radiation treatment (RT) plan and to minimise the risk of toxicity. Furthermore, accurate contouring in clinical practice on a large scale would allow more accurate dose estimation as input for normal tissue complication probability models.
In this context, 10 OARs were introduced in the updated European Particle Therapy Network (EPTN) neurological contouring atlas (i.e., amygdala, caudate nucleus, corpus callosum, fornix, macula, optic tract, orbitofrontal cortex, periventricular space, pineal gland, and thalamus).
Despite the use of this atlas, inter-individual variations in contouring may persist. To further facilitate accurate contouring of these OARs and training of new delineation professionals, educational movies were developed based on experience gathered during multidisciplinary contouring training sessions.
Material and Methods
Weekly contouring training sessions designed for members of different disciplines involved in contouring [i.e. radiation oncologist (RTO), radiation technologist (RTT), clinical scientist, and medical student] were organised in our RT department. During each weekly session, 1 of the 10 new OARs was introduced. Before the session, participants were asked to perform the contouring on a patient image set (CT/MR scans) based on the updated EPTN atlas. Then, during each session, inter-individual delineation differences were discussed with an experienced neuroradiologist. This OAR was subsequently delineated again during the next weekly sessions on new patient study sets until visual contouring agreement was reached.
Results
The sessions lead to a clear reduction in inter-individual contouring variability (Fig. 1). Based on the observations made during the training sessions, educational movies describing the OARs were developed in order to be used by the different professionals involved in contouring. These movies show the anatomical boundaries of the OARs and provide tips and tricks to help with common difficulties and errors experienced during contouring. The movies were reviewed by an experienced neuroradiologist, two RTTs, two RTOs who did not participate to the meetings, as well as by an external RTO expert in neuro-oncology.
Figure 1.
A clear reduction in inter-individual contouring variability was observed when comparing the delineations of the participants during the first training session (m1) and the second one (m2), as illustrated for the corpus callosum, amygdala, and thalamus.
Conclusion
Explanatory movies were developed with the aim of reducing inter- and intra-individual variability in the delineation of the 10 OARs introduced in the updated EPTN atlas. These movies will be made available on www.cancerdata.org.