scholarly journals Delayed-enhancement magnetic resonance simulation imaging for prone radiotherapy after breast-conserving surgery: Assessing its application in lumpectomy cavity delineation based on deformable image registration

2021 ◽  
Author(s):  
changhui Zhao ◽  
Jianbin Li ◽  
Wei Wang ◽  
Guanzhong Gong ◽  
Liang Xu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Registration ◽  
Center Of Mass ◽  
Deformable Image Registration ◽  
Breast Conserving Surgery ◽  
Observer Variation ◽  
Delayed Enhancement ◽  
Conformity Index ◽  
Surgical Clips ◽  
Lumpectomy Cavity

Abstract Background The application of delayed-enhancement magnetic resonance (DE-MR) simulation imaging in lumpectomy cavity (LC) delineation for prone radiotherapy in patients with an invisible seroma or a low seroma clarity score (SCS) after breast-conserving surgery (BCS) based on deformable image registration (DIR) was assessed. Methods Twenty-six patients who were suitable for radiotherapy in prone positions after BCS were enrolled, and both computed tomography (CT) and DE-MR simulation scans were acquired. The LC delineated based on titanium surgical clips on CT images was denoted as LCCT. The LC delineated based on the signal of cavity boundaries on fat-suppressed T2-weighted imaging (T2WI) and multiphase delayed-enhancement T1-weighted imaging (DE-T1WI), which was performed at 2 min, 5 min and 10 min postinjection, were denoted as LCT2, LC2T1, LC5T1 and LC10T1, respectively. Afterwards, DIR was performed to compare the volumes and locations of the LCs with MIM software. The generalized conformity index (CIgen) of inter (intra) observer (Inter-CIgen and Intra-CIgen) was also used to explore the inter(intra) observer variation for LC delineation on each image modality. Results LCCT-LC10T1 provided the best conformal index (CI) and degree of inclusion (DI), increasing by 2.08% and 4.48% compared to LCCT-LCT2, 11.36% and 2.94% for LCCT-LC2T1, and 8.89% and 7.69% for LC5T1-LCCT, respectively. The center of mass (COM) of LCCT-LC10T1 decreased by 17.86%, 6.12% and 13.21% compared with that of LCCT-LCT2, LCCT-LC2T1 and LCCT-LC5T1, respectively. The agreement of LC delineation was strongest for 10th min DE-TIWI (coefficient of variation, COV = 2.30%, Inter-CIgen = 87.06%, Intra-CIgen = 92.64%). Conclusion For patients with a low SCS (SCS ≤ 2) after BCS, it is feasible to contour the LC based on prone DE-MR simulation images. Furthermore, the LC derived from prone DE-T1WI at 10 min was found to be most similar to that derived from prone CT simulation scans using titanium surgical clips regardless of the volume and location of the LC. Inter(intra)variability was minimal for the delineation of the LC based on 10th min DE-TIWI.

scholarly journals DE-MR simulation imaging for prone radiotherapy after breast-conserving surgery: assessing its application in lumpectomy cavity delineation based on deformable image registration

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Changhui Zhao ◽  
Jianbin Li ◽  
Wei Wang ◽  
Guanzhong Gong ◽  
Liang Xu ◽  
...  
Keyword(s):  
Image Registration ◽  
Center Of Mass ◽  
Deformable Image Registration ◽  
Breast Conserving Surgery ◽  
Observer Variation ◽  
Delayed Enhancement ◽  
Conformity Index ◽  
Surgical Clips ◽  
Lumpectomy Cavity ◽  
Ct Simulation

Abstract Background The application of delayed-enhancement magnetic resonance (DE-MR) simulation imaging in lumpectomy cavity (LC) delineation for prone radiotherapy in patients with an invisible seroma or a low seroma clarity score (SCS) after breast-conserving surgery (BCS) based on deformable image registration (DIR) was assessed. Methods Twenty-six patients who were suitable for radiotherapy in prone positions after BCS were enrolled, and both computed tomography (CT) and DE-MR simulation scans were acquired. The LC delineated based on titanium surgical clips on CT images was denoted as LCCT. The LC delineated based on the signal of cavity boundaries on fat-suppressed T2-weighted imaging (T2WI) and multiphase delayed-enhancement T1-weighted imaging (DE-T1WI), which was performed at 2 min, 5 min and 10 min postinjection, were denoted as LCT2, LC2T1, LC5T1 and LC10T1, respectively. Afterwards, DIR was performed to compare the volumes and locations of the LCs with MIM software. The generalized conformity index (CIgen) of inter (intra) observer (Inter-CIgen and Intra-CIgen) was also used to explore the inter(intra) observer variation for LC delineation on each image modality. Results LCCT–LC10T1 provided the best conformal index (CI) and degree of inclusion (DI), increasing by 2.08% and 4.48% compared to LCCT–LCT2, 11.36% and 2.94% for LCCT–LC2T1, and 8.89% and 7.69% for LC5T1–LCCT, respectively. The center of mass (COM) of LCCT–LC10T1 decreased by 17.86%, 6.12% and 13.21% compared with that of LCCT–LCT2, LCCT–LC2T1 and LCCT–LC5T1, respectively. The agreement of LC delineation was strongest for 10th min DE-TIWI (coefficient of variation, COV = 2.30%, Inter-CIgen = 87.06%, Intra-CIgen = 92.64%). Conclusion For patients with a low SCS (SCS ≤ 2) after BCS, it is feasible to contour the LC based on prone DE-MR simulation images. Furthermore, the LC derived from prone DE-T1WI at 10 min was found to be most similar to that derived from prone CT simulation scans using titanium surgical clips regardless of the volume and location of the LC. Inter (intra) variability was minimal for the delineation of the LC based on 10th min DE-TIWI.

scholarly journals A Comparative Evaluation of 3 Different Free-Form Deformable Image Registration and Contour Propagation Methods for Head and Neck MRI: The Case of Parotid Changes During Radiotherapy

2017 ◽  
Vol 16 (3) ◽  
pp. 373-381 ◽  
Author(s):  
Sara Broggi ◽  
Elisa Scalco ◽  
Maria Luisa Belli ◽  
Gerlinde Logghe ◽  
Dirk Verellen ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Registration ◽  
Head And Neck ◽  
Deformable Image Registration ◽  
Similarity Coefficient ◽  
Free Form ◽  
Dice Similarity Coefficient ◽  
Contour Propagation ◽  
Free Form Deformation ◽  
Symmetric Distance

Purpose: To validate and compare the deformable image registration and parotid contour propagation process for head and neck magnetic resonance imaging in patients treated with radiotherapy using 3 different approaches—the commercial MIM, the open-source Elastix software, and an optimized version of it. Materials and Methods: Twelve patients with head and neck cancer previously treated with radiotherapy were considered. Deformable image registration and parotid contour propagation were evaluated by considering the magnetic resonance images acquired before and after the end of the treatment. Deformable image registration, based on free-form deformation method, and contour propagation available on MIM were compared to Elastix. Two different contour propagation approaches were implemented for Elastix software, a conventional one (DIR_Trx) and an optimized homemade version, based on mesh deformation (DIR_Mesh). The accuracy of these 3 approaches was estimated by comparing propagated to manual contours in terms of average symmetric distance, maximum symmetric distance, Dice similarity coefficient, sensitivity, and inclusiveness. Results: A good agreement was generally found between the manual contours and the propagated ones, without differences among the 3 methods; in few critical cases with complex deformations, DIR_Mesh proved to be more accurate, having the lowest values of average symmetric distance and maximum symmetric distance and the highest value of Dice similarity coefficient, although nonsignificant. The average propagation errors with respect to the reference contours are lower than the voxel diagonal (2 mm), and Dice similarity coefficient is around 0.8 for all 3 methods. Conclusion: The 3 free-form deformation approaches were not significantly different in terms of deformable image registration accuracy and can be safely adopted for the registration and parotid contour propagation during radiotherapy on magnetic resonance imaging. More optimized approaches (as DIR_Mesh) could be preferable for critical deformations.

scholarly journals Accuracy of deformable image registration on magnetic resonance images in digital and physical phantoms

2017 ◽  
Vol 44 (10) ◽  
pp. 5153-5161 ◽  
Author(s):  
Rachel B. Ger ◽  
Jinzhong Yang ◽  
Yao Ding ◽  
Megan C. Jacobsen ◽  
Clifton D. Fuller ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Registration ◽  
Deformable Image Registration ◽  
Magnetic Resonance Images
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