Dosimetric evaluation of MRI-to-ultrasound automated image registration algorithms for prostate brachytherapy
Autor: | Chia-Lin Tseng, Hans Chung, Andrew Loblaw, Lucas C. Mendez, Amani Shaaer, Melanie Davidson, Gerard Morton, Moti Paudel, Mark Semple, Ananth Ravi, Alexandru Nicolae |
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Rok vydání: | 2020 |
Předmět: |
Male
Organs at Risk Trus image medicine.medical_treatment Brachytherapy Statistical difference Image registration 030218 nuclear medicine & medical imaging Workflow 03 medical and health sciences 0302 clinical medicine Urethra medicine Image Processing Computer-Assisted Dosimetry Humans Radiology Nuclear Medicine and imaging Radiation treatment planning Radiometry Ultrasonography business.industry Radiotherapy Planning Computer-Assisted Ultrasound Rectum Prostatic Neoplasms Radiotherapy Dosage Magnetic Resonance Imaging Oncology 030220 oncology & carcinogenesis business Algorithm Prostate brachytherapy Algorithms |
Zdroj: | Brachytherapy. 19(5) |
ISSN: | 1873-1449 |
Popis: | Purpose Identifying dominant intraprostatic lesions (DILs) on transrectal ultrasound (TRUS) images during prostate high-dose-rate brachytherapy treatment planning remains a significant challenge. Multiparametric MRI (mpMRI) is the tool of choice for DIL identification; however, the geometry of the prostate on mpMRI and on the TRUS may differ significantly, requiring image registration. This study assesses the dosimetric impact attributed to differences in DIL contours generated using commonly available MRI to TRUS automated registration: rigid, semi-rigid, and deformable image registration, respectively. Methods and Materials Ten patients, each with mpMRI and TRUS data sets, were included in this study. Five radiation oncologists with expertise in TRUS-based high-dose-rate brachytherapy were asked cognitively to transfer the DIL from the mpMRI images of each patient to the TRUS image. The contours were analyzed for concordance using simultaneous truth and performance level estimation (STAPLE) algorithm. The impact of DIL contour differences due to registration variability was evaluated by comparing the STAPLE-DIL dosimetry from the reference (STAPLE) plan with that from the evaluation plans (manual and automated registration) for each patient. The dosimetric impact of the automatic registration approach was also validated using a margin expansion that normalizes the volume of the autoregistered DILs to the volumes of the STAPLE-DILs. Dose metrics including D90, Dmean, V150, and V200 to the prostate and DIL were reported. For urethra and rectum, D10 and V80 were reported. Results Significant differences in DIL coverage between reference and evaluation plans were found regardless of the algorithm methodology. No statistical difference was reported in STAPLE-DIL dosimetry when manual registration was used. A margin of 1.5 ± 0.8 mm, 1.1 ± 0.8 mm, and 2.5 ± 1.6 mm was required to be added for rigid, semi-rigid, and deformable registration, respectively, to mitigate the difference in STAPLE-DIL coverage between the evaluation and reference plans. Conclusion The dosimetric impact of integrating an MRI-delineated DIL into a TRUS-based brachytherapy workflow has been validated in this study. The results show that rigid, semi-rigid, and deformable registration algorithms lead to a significant undercoverage of the DIL D90 and Dmean. A margin of at least 1.5 ± 0.8 mm, 1.1 ± 0.8 mm, and 2.5 ± 1.6 mm is required to be added to the rigid, semi-rigid, and deformable DIL registration to be suitable for DIL-boosting during prostate brachytherapy. |
Databáze: | OpenAIRE |
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