Back to Search
Start Over
Postimplant Dosimetry of Permanent Prostate Brachytherapy: Comparison of MRI-Only and CT-MRI Fusion-Based Workflows.
- Source :
-
International journal of radiation oncology, biology, physics [Int J Radiat Oncol Biol Phys] 2020 Jan 01; Vol. 106 (1), pp. 206-215. Date of Electronic Publication: 2019 Oct 15. - Publication Year :
- 2020
-
Abstract
- Purpose: The current magnetic resonance imaging-computed tomography (MRI-CT) fusion-based workflow for postimplant dosimetry of low-dose-rate (LDR) prostate brachytherapy takes advantage of the superior soft tissue contrast of MRI, but still relies on CT for seed visualization and detection. Recently an MR-only workflow has been proposed that employs standard MR sequences and visualizes conventional implanted seed with positive contrast solely through MR postprocessing. In this work, the novel MR-only based workflow is compared with the clinical CT-MRI fusion approach.<br />Methods and Materials: Twenty-four prostate patients with a total of 1775 implanted LDR seeds were scanned using a 3-dimensional multiecho gradient echo sequence on a 3 Tesla MR scanner within 30 days after implantation. Quantitative susceptibility mapping was used for seed visualization. Seeds were automatically segmented and localized on the quantitative susceptibility mapping using convolutional neural network and k-means clustering, respectively. To assess the MR-only seed localization error, CT and MR-derived seed positions were coregistered, and ultimately, the resulting dose-volume histograms were compared.<br />Results: The MR-based seed visualization, segmentation, and localization generated comparable results to the CT-MR registration approach. The accuracy of the MRI-only based seed identification was 99.1%. After a rigid registration between the MR and CT-derived seed centroids, the average localization error was 0.8 ± 0.8 mm. The average prostate D <subscript>90</subscript> , V <subscript>100</subscript> , V <subscript>150</subscript> , and V <subscript>200</subscript> for MRI-only and CT-MR fusion based dosimetry were 114.3 ± 12.5% versus 113.9 ± 11.9%, 95.1 ± 3.7% versus 95.3 ± 3.8%, 54.5 ± 14.5% versus 55.0 ± 13.2% and 22.9 ± 6.8% versus 23.2 ± 6.7%, respectively. No significant differences were observed in 3-dimensional seed positions and dosimetric parameters between MR-only and CT-MR fusion-based workflows (P > 0.2).<br />Conclusions: The MRI-only LDR postimplant dosimetry is feasible and has very good potential to eliminate the need for CT-based seed identification.<br /> (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Subjects :
- Algorithms
Brachytherapy instrumentation
Feasibility Studies
Gases
Humans
Iodine Radioisotopes administration & dosage
Male
Prostatic Neoplasms pathology
Radiometry methods
Rectum diagnostic imaging
Time Factors
Brachytherapy methods
Magnetic Resonance Imaging
Multimodal Imaging methods
Prostatic Neoplasms diagnostic imaging
Prostatic Neoplasms radiotherapy
Tomography, X-Ray Computed
Workflow
Subjects
Details
- Language :
- English
- ISSN :
- 1879-355X
- Volume :
- 106
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- International journal of radiation oncology, biology, physics
- Publication Type :
- Academic Journal
- Accession number :
- 31627178
- Full Text :
- https://doi.org/10.1016/j.ijrobp.2019.10.009