Synthetic computed tomography for low-field magnetic resonance-guided radiotherapy in the abdomen.
Phys Imaging Radiat Oncol
; 24: 173-179, 2022 Oct.
Article
em En
| MEDLINE
| ID: mdl-36478992
ABSTRACT
Background and purpose:
The requirement of computed tomography (CT) for radiotherapy planning may be bypassed by synthetic CT (sCT) generated from magnetic resonance (MR), which has recently led to the clinical introduction of MR-only radiotherapy for specific sites. Further developments are required for abdominal sCT, mostly due to the presence of mobile air pockets affecting the dose calculation. In this study we aimed to overcome this limitation for abdominal sCT at a low field (0.35â¯T) hybrid MR-Linac. Materials andmethods:
A retrospective analysis was conducted enrolling 168 patients corresponding to 215 MR-CT pairs. After the exclusion criteria, 152 volumetric images were used to train the cycle-consistent generative adversarial network (CycleGAN) and 34 to test the sCT. Image similarity metrics and dose recalculation analysis were performed.Results:
The generated sCT faithfully reproduced the original CT and the location of the air pockets agreed with the MR scan. The dose calculation did not require manual bulk density overrides and the mean deviations of the dose-volume histogram dosimetric points were within 1â¯% of the CT, without any outlier above 2â¯%. The mean gamma passing rates were above 99â¯% for the 2â¯%/â¯2â¯mm analysis and no cases below 95â¯% were observed.Conclusions:
This study presented the implementation of CycleGAN to perform sCT generation in the abdominal region for a low field hybrid MR-Linac. The sCT was shown to correctly allocate the electron density for the mobile air pockets and the dosimetric analysis demonstrated the potential for future implementation of MR-only radiotherapy in the abdomen.
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Base de dados:
MEDLINE
Tipo de estudo:
Guideline
Idioma:
En
Revista:
Phys Imaging Radiat Oncol
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Suíça