Michael Cardoso1,2,3, Myo Min1,3,4,5,6,7, Michael Jameson1,3,4, Simon Tang1,4, Christopher Rumley1,8, Allan Fowler1, Vanessa Estall1, Elise Pogson1,2,4, Lois Holloway1,2,3,4,9, Dion Forstner1,3,4. 1. Cancer Therapy Centre, Liverpool Hospital, Liverpool, New South Wales, Australia. 2. Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia. 3. South Western Sydney Clinical School, University of New South Wales, Liverpool, New South Wales, Australia. 4. Ingham Institute of Applied Medical Research, Liverpool, New South Wales, Australia. 5. Sunshine Coast University Hospital, Birtinya, Queensland, Australia. 6. Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia. 7. School of Medicine, Griffith University, Gold Coast, Queensland, Australia. 8. Northern Territory Radiation Oncology, Royal Darwin Hospital, Darwin, Northern Territory, Australia. 9. Institute of Medical Physics, School of Physics, The University of Sydney, Sydney, New South Wales, Australia.
Abstract
INTRODUCTION: Inter-observer variability (IOV) in target volume delineation is a source of error in head and neck radiotherapy. Diffusion-weighted imaging (DWI) has been shown to be useful in detecting recurrent head and neck cancer. This study aims to determine whether DWI improves target volume delineation and IOV. METHODS: Four radiation oncologists delineated the gross tumour volume (GTV) for ten head and neck cancer patients. Delineation was performed on CT alone as well as fused image sets which incorporated fluorodeoxyglucose (FDG)-positron emission tomography (PET) and magnetic resonance imaging (MRI) in the form of CT/PET, CT/PET/T2W and CT/PET/T2W/DWI image sets. Analysis of the variability of contour volumes was completed by comparison to the simultaneous truth and performance level estimation (STAPLE) volumes. The DICE Similarity Coefficient (DSC) and other IOV metrics for each observer's contour were compared to the STAPLE for each patient and image dataset. A DWI usability scoresheet for delineation was completed. RESULTS: The CT/PET/T2W/DWI mean GTV volume of 13.37 (10.35-16.39)cm3 was shown to be different to the mean GTV of 10.92 (8.32-13.51)cm3 when using CT alone (P < 0.001). The GTV DSC amongst observers for CT alone was 0.72 (0.65-0.79), CT/PET was 0.73 (0.67-0.80), CT/PET/T2W was 0.71 (0.64-0.77) and CT/PET/T2W/DWI was 0.69 (0.61-0.75). CONCLUSION: Mean GTVs with the addition of DWI had slightly larger volumes compared to standard CT and CT/PET volumes. DWI may add supplemental visual information for GTV delineation while having a small impact on IOV, therefore potentially improving target volume delineation.
INTRODUCTION: Inter-observer variability (IOV) in target volume delineation is a source of error in head and neck radiotherapy. Diffusion-weighted imaging (DWI) has been shown to be useful in detecting recurrent head and neck cancer. This study aims to determine whether DWI improves target volume delineation and IOV. METHODS: Four radiation oncologists delineated the gross tumour volume (GTV) for ten head and neck cancerpatients. Delineation was performed on CT alone as well as fused image sets which incorporated fluorodeoxyglucose (FDG)-positron emission tomography (PET) and magnetic resonance imaging (MRI) in the form of CT/PET, CT/PET/T2W and CT/PET/T2W/DWI image sets. Analysis of the variability of contour volumes was completed by comparison to the simultaneous truth and performance level estimation (STAPLE) volumes. The DICE Similarity Coefficient (DSC) and other IOV metrics for each observer's contour were compared to the STAPLE for each patient and image dataset. A DWI usability scoresheet for delineation was completed. RESULTS: The CT/PET/T2W/DWI mean GTV volume of 13.37 (10.35-16.39)cm3 was shown to be different to the mean GTV of 10.92 (8.32-13.51)cm3 when using CT alone (P < 0.001). The GTV DSC amongst observers for CT alone was 0.72 (0.65-0.79), CT/PET was 0.73 (0.67-0.80), CT/PET/T2W was 0.71 (0.64-0.77) and CT/PET/T2W/DWI was 0.69 (0.61-0.75). CONCLUSION: Mean GTVs with the addition of DWI had slightly larger volumes compared to standard CT and CT/PET volumes. DWI may add supplemental visual information for GTV delineation while having a small impact on IOV, therefore potentially improving target volume delineation.
Authors: Jens P E Schouten; Samantha Noteboom; Roland M Martens; Steven W Mes; C René Leemans; Pim de Graaf; Martijn D Steenwijk Journal: Cancer Imaging Date: 2022-01-15 Impact factor: 3.909
Authors: Ruta Zukauskaite; Christopher N Rumley; Christian R Hansen; Michael G Jameson; Yuvnik Trada; Jørgen Johansen; Niels Gyldenkerne; Jesper G Eriksen; Farhannah Aly; Rasmus L Christensen; Mark Lee; Carsten Brink; Lois Holloway Journal: Clin Transl Radiat Oncol Date: 2022-08-06