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Evaluating diffusion‐weighted magnetic resonance imaging for target volume delineation in head and neck radiotherapy
Author(s) -
Cardoso Michael,
Min Myo,
Jameson Michael,
Tang Simon,
Rumley Christopher,
Fowler Allan,
Estall Vanessa,
Pogson Elise,
Holloway Lois,
Forstner Dion
Publication year - 2019
Publication title -
journal of medical imaging and radiation oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.31
H-Index - 43
eISSN - 1754-9485
pISSN - 1754-9477
DOI - 10.1111/1754-9485.12866
Subject(s) - medicine , nuclear medicine , magnetic resonance imaging , radiation therapy , positron emission tomography , head and neck cancer , head and neck , diffusion mri , effective diffusion coefficient , contouring , radiology , fluorodeoxyglucose , computer science , surgery , computer graphics (images)
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)cm 3 was shown to be different to the mean GTV of 10.92 (8.32–13.51)cm 3 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 GTV s 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.