Christina Hague1, William Beasley2, Lynne Dixon3, Simona Gaito4, Kate Garcez5, Andrew Green6, Lip W Lee7, Massimo Maranzano8, Andrew McPartlin9, Hitesh Mistry10, Damian Mullan11, Andrew J Sykes12, David Thomson13, Marcel Van Herk14, Catharine M West15, Nick Slevin16. 1. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: Christina.hague@christie.nhs.uk. 2. Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Heath, University of Manchester, Manchester Academic Health Science Centre, UK. Electronic address: William.beasley@christie.nhs.uk. 3. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: lynne.dixon3@nhs.net. 4. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: simona.gaito@christie.nhs.uk. 5. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: Kate.garcez@christie.nhs.uk. 6. Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Heath, University of Manchester, Manchester Academic Health Science Centre, UK; Department of Radiotherapy Related Research, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: Andrew.green-2@manchester.ac.uk. 7. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: lipwai.lee@christie.nhs.uk. 8. Department of Oral-Maxillo-Facial and Plastic Reconstructive Surgery, Central Manchester University Hospitals, UK. Electronic address: massimo.maranzano@postgrad.manchester.ac.uk. 9. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: Andrew.mcpartlin@christie.nhs.uk. 10. Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Heath, University of Manchester, Manchester Academic Health Science Centre, UK. Electronic address: hitesh.mistry@manchester.ac.uk. 11. Department of Radiology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: damian.mullan@christie.nhs.uk. 12. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: Andrew.sykes@christie.nhs.uk. 13. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: david.thomson@christie.nhs.uk. 14. Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Heath, University of Manchester, Manchester Academic Health Science Centre, UK; Department of Radiotherapy Related Research, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: marcel.vanherk@manchester.ac.uk. 15. Translational Radiobiology Group, Division of Cancer Sciences, Manchester Academic Health Science Centre, University of Manchester, The Christie NHS Foundation Trust, UK. Electronic address: Catharine.west@manchester.ac.uk. 16. Department of Head and Neck Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK. Electronic address: nick.slevin@christie.nhs.uk.
Abstract
PURPOSE/OBJECTIVE(S): Trismus is caused by injury to the masticatory muscles resulting from cancer or its treatment. Contouring these muscles to reduce dose and radiation related trismus can be problematic due to interobserver variability. This study aimed to evaluate the reduction in interobserver variability achievable with a new contouring atlas. MATERIALS/ METHODS: The atlas included: medial and lateral pterygoids (MP, LP), masseter (M) and temporalis (T) muscles, and the temporo-mandibular joint (TMJ). Seven clinicians delineated five paired structures on CT scans from 5 patients without the atlas. After ≥5 weeks, contouring was repeated using the atlas. Using contours generated by the clinicians on the same 5 CT scans as reference, dice similarity coefficient (DSC), mean distance-to-agreement (DTA) and centre of mass (COM) difference were compared with and without the atlas. Comparison was also performed split by training grade. Mean and standard deviation (SD) values were measured. RESULTS: The atlas reduced interobserver variability for all structures. Mean DTA significantly improved for MP (p = 0.01), M (p < 0.01), T (p < 0.01) and TMJ (p < 0.01). Mean DTA improved using the atlas for the trainees across all muscles, with the largest reduction in variability observed for the T (4.3 ± 7.1 v 1.2 ± 0.4 mm, p = 0.06) and TMJ (2.1 ± 0.7 v 0.8 ± 0.3 mm, p < 0.01). Distance between the COM and interobserver variability reduced in all directions for MP and T. CONCLUSION: A new atlas for contouring masticatory muscles during radiotherapy planning for head and neck cancer reduces interobserver variability and could be used as an educational tool.
PURPOSE/OBJECTIVE(S): Trismus is caused by injury to the masticatory muscles resulting from cancer or its treatment. Contouring these muscles to reduce dose and radiation related trismus can be problematic due to interobserver variability. This study aimed to evaluate the reduction in interobserver variability achievable with a new contouring atlas. MATERIALS/ METHODS: The atlas included: medial and lateral pterygoids (MP, LP), masseter (M) and temporalis (T) muscles, and the temporo-mandibular joint (TMJ). Seven clinicians delineated five paired structures on CT scans from 5 patients without the atlas. After ≥5 weeks, contouring was repeated using the atlas. Using contours generated by the clinicians on the same 5 CT scans as reference, dice similarity coefficient (DSC), mean distance-to-agreement (DTA) and centre of mass (COM) difference were compared with and without the atlas. Comparison was also performed split by training grade. Mean and standard deviation (SD) values were measured. RESULTS: The atlas reduced interobserver variability for all structures. Mean DTA significantly improved for MP (p = 0.01), M (p < 0.01), T (p < 0.01) and TMJ (p < 0.01). Mean DTA improved using the atlas for the trainees across all muscles, with the largest reduction in variability observed for the T (4.3 ± 7.1 v 1.2 ± 0.4 mm, p = 0.06) and TMJ (2.1 ± 0.7 v 0.8 ± 0.3 mm, p < 0.01). Distance between the COM and interobserver variability reduced in all directions for MP and T. CONCLUSION: A new atlas for contouring masticatory muscles during radiotherapy planning for head and neck cancer reduces interobserver variability and could be used as an educational tool.
Authors: Dario Di Perri; David Hofstede; Alida Postma; Catharina M L Zegers; Lieke In't Ven; Frank Hoebers; Wouter van Elmpt; Lindsey Verheesen; Hilde Beurskens; Esther G C Troost; Inge Compter; Danielle B P Eekers Journal: Clin Transl Radiat Oncol Date: 2022-02-15
Authors: Wen Chen; Yimin Li; Brandon A Dyer; Xue Feng; Shyam Rao; Stanley H Benedict; Quan Chen; Yi Rong Journal: Radiat Oncol Date: 2020-07-20 Impact factor: 3.481
Authors: Xiangguo Zhang; Haihui Chen; Wen Chen; Brandon A Dyer; Quan Chen; Stanley H Benedict; Shyam Rao; Yi Rong Journal: J Appl Clin Med Phys Date: 2020-08-25 Impact factor: 2.102