Permanent prostate brachytherapy postimplant magnetic resonance imaging dosimetry using positive contrast magnetic resonance imaging markers
Autor: | Jihong Wang, Pierre Blanchard, Geoffrey V. Martin, Rajat J. Kudchadker, Teresa L. Bruno, Usama Mahmood, Thomas J. Pugh, Steven J. Frank, Tharakeswara K. Bathala |
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Rok vydání: | 2017 |
Předmět: |
medicine.medical_specialty
medicine.diagnostic_test Dose calculation business.industry medicine.medical_treatment Brachytherapy Permanent prostate brachytherapy Magnetic resonance imaging 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine medicine.anatomical_structure Oncology Positive contrast Prostate 030220 oncology & carcinogenesis Medicine Dosimetry Radiology Nuclear Medicine and imaging Radiology business Nuclear medicine Postimplant dosimetry |
Zdroj: | Brachytherapy. 16:761-769 |
ISSN: | 1538-4721 |
Popis: | Purpose Permanent prostate brachytherapy dosimetry using computed tomography-magnetic resonance imaging (CT-MRI) fusion combines the anatomic detail of MRI with seed localization on CT but requires multimodality imaging acquisition and fusion. The purpose of this study was to compare the utility of MRI only postimplant dosimetry to standard CT-MRI fusion-based dosimetry. Methods and Materials Twenty-three patients undergoing permanent prostate brachytherapy with use of positive contrast MRI markers were included in this study. Dose calculation to the whole prostate, apex, mid-gland, and base was performed via standard CT-MRI fusion and MRI only dosimetry with prostate delineated on the same T2 MRI sequence. The 3-dimensional (3D) distances between seed positions of these two methods were also evaluated. Wilcoxon-matched-pair signed-rank test compared the D90 and V100 of the prostate and its sectors between methods. Results The day 0 D90 and V100 for the prostate were 98% versus 94% and 88% versus 86% for CT-MRI fusion and MRI only dosimetry. There were no differences in the D90 or V100 of the whole prostate, mid-gland, or base between dosimetric methods ( p > 0.19), but prostate apex D90 was high by 13% with MRI dosimetry ( p = 0.034). The average distance between seeds on CT-MRI fusion and MRI alone was 5.5 mm. After additional automated rigid registration of 3D seed positions, the average distance between seeds was 0.3 mm, and the previously observed differences in apex dose between methods was eliminated ( p > 0.11). Conclusions Permanent prostate brachytherapy dosimetry based only on MRI using positive contrast MRI markers is feasible, accurate, and reduces the uncertainties arising from CT-MRI fusion abating the need for postimplant multimodality imaging. |
Databáze: | OpenAIRE |
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