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Clinical relevance of metal artefact reduction in computed tomography ( iMAR ) in the pelvic and head and neck region: Multi‐institutional contouring study of gross tumour volumes and organs at risk on clinical cases
Author(s) -
Hagen Marius,
Kretschmer Matthias,
Würschmidt Florian,
Gauer Tobias,
Giro Christian,
Karsten Elias,
Lorenzen Jörn
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 - 10.1111/1754-9485.12924
Subject(s) - contouring , medicine , computed tomography , head and neck , nuclear medicine , radiology , surgery , computer science , computer graphics (images)
Artefacts caused by dental implants and hip replacements may impede target volume definition and dose calculation accuracy. The iterative metal artefact reduction ( iMAR ) algorithm can provide a solution for this problem. The present study compares delineation of gross tumour volumes ( GTV s) and organs at risk ( OAR s) in the pelvic and the head and neck (H & N) regions using computed tomography ( CT ) with and without iMAR , and thus the practical applicability of iMAR for routine clinical use. Methods The native planning CT and CT ‐ iMAR data of two typical clinical cases with image‐distorting artefacts were used for multi‐institutional contouring and analysis using the Dice similarity coefficient ( DSC ). GTV / OAR contours were compared with an intraobserver approach and compared to predefined reference structures. Results Mean volume for GTV prostate in the intraobserver approach decreased from 87 ± 44 cm 3 (native CT ) to 75 ± 22 cm 3 ( CT ‐ iMAR ) ( P = 0.168). Compared to the reference, DSC values for GTV P rostate increased from 0.68 ± 0.15 to 0.78 ± 0.07 ( CT vs. iMAR ) ( P < 0.05). In the H & N region, the reference for GTV T ongue (34 cm 3 ) was underestimated on both data sets. No significant improvement in DSC values (0.83 ± 0.06 (native CT ) versus 0.86 ± 0.06 ( CT ‐ iMAR )) was observed. Conclusion The use of iMAR improves the anatomical delineation at the transition of prostate and bladder in cases of bilateral hip replacement. In the H & N region, anatomical residual structures and experience were apparently sufficient for precise contouring.