Susan Mercieca1, José S A Belderbos2, Katrien De Jaeger3, Dominic A X Schinagl4, Noëlle van der Voort Van Zijp5, Jacqueline Pomp6, Jacqueline Theuws3, Jonathan Khalifa7, Paul van de Vaart5, Marcel van Herk8. 1. Faculty of Health Science, University of Malta, Malta. Electronic address: susan.mercieca@um.edu.mt. 2. Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands. 3. Department of Radiotherapy, Catharina Hospital, Eindhoven, The Netherlands. 4. Radboud University Medical Centre, Department of Radiation Oncology, Nijmegen, The Netherlands. 5. Department of Radiation Oncology, MC Haaglanden, The Hague, The Netherlands. 6. Department of Radiotherapy, MST, Dept. of Radiotherapy Enschede, The Netherlands. 7. Department of Radiation Oncology, Institut Universitaire du Cancer de Toulouse - Oncopole, France. 8. University of Manchester, Manchester Academic Health Centre, The Christie NHS Foundation Trust, United Kingdom.
Abstract
PURPOSE: The study compared interobserver variation in the delineation of the primary tumour (GTVp) and lymph nodes (GTVln) between three different 4DCT reconstruction types; Maximum Intensity Projection (MIP), Mid-Ventilation (Mid-V) and Mid-Position (Mid-P). MATERIAL AND METHODS: Seven radiation oncologists delineated the GTVp and GTVln on the MIP, Mid-V and Mid-P 4DCT image reconstructions of 10 lung cancer patients. The volumes, the mean standard deviation (SD) and distribution of SD (SD/area) over the median surface contour were compared for different tumour regions. RESULTS: The overall mean delineated volume on the MIP was significantly larger (p < 0.001) than the Mid-V and Mid-P. For the GTVp the Mid-P had the lowest interobserver variation (SD = 0.261 cm), followed by Mid-V (SD = 0.314 cm) and MIP (SD = 0.330 cm) For GTVln the Mid-V had the lowest interobserver variation (SD = 0.425 cm) followed by the MIP (SD = 0.477 cm) and Mid-P (SD = 0.543 cm). The SD/area distribution showed a statistically significant difference between the MIP versus Mid-P and Mid-P versus Mid-V for both GTVp and GTVln (p < 0.001), with outliers indicating interpretation differences for GTVp located close to the mediastinum and GTVln. CONCLUSION: The Mid-P reduced the interobserver variation for the GTVp. Delineation protocols must be improved to benefit from the improved image quality of Mid-P for the GTVln.
PURPOSE: The study compared interobserver variation in the delineation of the primary tumour (GTVp) and lymph nodes (GTVln) between three different 4DCT reconstruction types; Maximum Intensity Projection (MIP), Mid-Ventilation (Mid-V) and Mid-Position (Mid-P). MATERIAL AND METHODS: Seven radiation oncologists delineated the GTVp and GTVln on the MIP, Mid-V and Mid-P 4DCT image reconstructions of 10 lung cancerpatients. The volumes, the mean standard deviation (SD) and distribution of SD (SD/area) over the median surface contour were compared for different tumour regions. RESULTS: The overall mean delineated volume on the MIP was significantly larger (p < 0.001) than the Mid-V and Mid-P. For the GTVp the Mid-P had the lowest interobserver variation (SD = 0.261 cm), followed by Mid-V (SD = 0.314 cm) and MIP (SD = 0.330 cm) For GTVln the Mid-V had the lowest interobserver variation (SD = 0.425 cm) followed by the MIP (SD = 0.477 cm) and Mid-P (SD = 0.543 cm). The SD/area distribution showed a statistically significant difference between the MIP versus Mid-P and Mid-P versus Mid-V for both GTVp and GTVln (p < 0.001), with outliers indicating interpretation differences for GTVp located close to the mediastinum and GTVln. CONCLUSION: The Mid-P reduced the interobserver variation for the GTVp. Delineation protocols must be improved to benefit from the improved image quality of Mid-P for the GTVln.
Authors: Lydia A den Otter; Renske M Anakotta; Menkedina Weessies; Catharina T G Roos; Nanna M Sijtsema; Christina T Muijs; Margriet Dieters; Robin Wijsman; Esther G C Troost; Christian Richter; Arturs Meijers; Johannes A Langendijk; Stefan Both; Antje-Christin Knopf Journal: Med Phys Date: 2020-07-09 Impact factor: 4.071
Authors: Hans Ligtenberg; Sara L Hackett; Laura G Merckel; Louk Snoeren; Charis Kontaxis; Cornel Zachiu; Gijsbert H Bol; Joost J C Verhoeff; Martin F Fast Journal: Phys Imaging Radiat Oncol Date: 2022-05-24