PURPOSE: This study aims to determine magnitude, causes and consequences of post-operative breast tumour target volume delineation variation among radiation oncologists in the presence of guidelines. MATERIALS AND METHODS: Excision cavities, CTVs and PTVs of eight breast cancer patients were delineated on CT scans by 13 Dutch radiation oncologists (observers) from 12 Dutch institutes participating in the international Young Boost Trial. Delineated volumes and conformity indices were determined. CTV delineation variation (SD) was determined for anatomically relevant regions. Non-parametric statistics were performed to establish effects of observers, patient characteristics and regions on delineation variation. RESULTS: Even in the presence of delineation guidelines considerable delineation variation is present (0.24<SD<1.22 cm). Presence of clips or seroma reduced interobserver variation (0.24<SD<0.62 cm). Region-specific analysis showed distinct regions of higher variability per patient. This could not always be ascribed to anatomical features, suggesting interobserver variation is not solely due to lack of image quality. CONCLUSIONS: In this study, interobserver delineation variation in breast tumour target volume delineation is larger than, e.g. setup inaccuracies and results from limited reliable visual guidance as well as interpretation differences between observers, despite guidelines. Reduction of delineation variation is essential in view of current developments in planning techniques, particularly for External Partial Breast Irradiation. (c) 2010 Elsevier Ireland Ltd. All rights reserved.
PURPOSE: This study aims to determine magnitude, causes and consequences of post-operative breast tumour target volume delineation variation among radiation oncologists in the presence of guidelines. MATERIALS AND METHODS: Excision cavities, CTVs and PTVs of eight breast cancerpatients were delineated on CT scans by 13 Dutch radiation oncologists (observers) from 12 Dutch institutes participating in the international Young Boost Trial. Delineated volumes and conformity indices were determined. CTV delineation variation (SD) was determined for anatomically relevant regions. Non-parametric statistics were performed to establish effects of observers, patient characteristics and regions on delineation variation. RESULTS: Even in the presence of delineation guidelines considerable delineation variation is present (0.24<SD<1.22 cm). Presence of clips or seroma reduced interobserver variation (0.24<SD<0.62 cm). Region-specific analysis showed distinct regions of higher variability per patient. This could not always be ascribed to anatomical features, suggesting interobserver variation is not solely due to lack of image quality. CONCLUSIONS: In this study, interobserver delineation variation in breast tumour target volume delineation is larger than, e.g. setup inaccuracies and results from limited reliable visual guidance as well as interpretation differences between observers, despite guidelines. Reduction of delineation variation is essential in view of current developments in planning techniques, particularly for External Partial Breast Irradiation. (c) 2010 Elsevier Ireland Ltd. All rights reserved.
Authors: Thomas Mulliez; Akos Gulyban; Tom Vercauteren; Annick van Greveling; Bruno Speleers; Wilfried De Neve; Liv Veldeman Journal: Strahlenther Onkol Date: 2016-02-10 Impact factor: 3.621
Authors: Rawan Allozi; X Allen Li; Julia White; Aditya Apte; An Tai; Jeff M Michalski; Walter R Bosch; Issam El Naqa Journal: Radiother Oncol Date: 2010-08-11 Impact factor: 6.280