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Magnetic resonance imaging-guided brachytherapy for cervical cancer: initiating a program.

Owrangi AM, Prisciandaro JI, Soliman A, Ravi A, Song WY - J Contemp Brachytherapy (2015)

Bottom Line: Over the past decade, the application of magnetic resonance imaging (MRI) has increased, and there is growing evidence to suggest that improvements in accuracy of target delineation in MRI-guided brachytherapy may improve clinical outcomes in cervical cancer.It is imperative to know that the most important source of uncertainty in the treatment process is related to target delineation and therefore, the necessity of training and expertise as well as quality assurance should be emphasized.A short review of concepts and techniques that have been developed for implementation and/or improvement of workflow of a MRI-guided brachytherapy program are provided in this document, so that institutions can use and optimize some of them based on their resources to minimize their procedure times.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada ; Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA ; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.

ABSTRACT
Over the past decade, the application of magnetic resonance imaging (MRI) has increased, and there is growing evidence to suggest that improvements in accuracy of target delineation in MRI-guided brachytherapy may improve clinical outcomes in cervical cancer. To implement a high quality image guided brachytherapy program, a multidisciplinary team is required with appropriate expertise as well as an adequate patient load to ensure a sustainable program. It is imperative to know that the most important source of uncertainty in the treatment process is related to target delineation and therefore, the necessity of training and expertise as well as quality assurance should be emphasized. A short review of concepts and techniques that have been developed for implementation and/or improvement of workflow of a MRI-guided brachytherapy program are provided in this document, so that institutions can use and optimize some of them based on their resources to minimize their procedure times.

No MeSH data available.


Related in: MedlinePlus

Comparison of CT, T1w and T2w images of a patient with a titanium ring and tandem in place. Transverse view of CT (top row), T1w (middle row) and T2w (bottom row) of a patient's pelvis with para-axial view showed in left panel and para-coronal and para-sagittal views showed in middle and right panels, respectively. The volumes are as follows: high-risk CTV (cyan), bladder (yellow), rectum (magenta). A – anterior, P – posterior, H – head, F – feet
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Figure 0002: Comparison of CT, T1w and T2w images of a patient with a titanium ring and tandem in place. Transverse view of CT (top row), T1w (middle row) and T2w (bottom row) of a patient's pelvis with para-axial view showed in left panel and para-coronal and para-sagittal views showed in middle and right panels, respectively. The volumes are as follows: high-risk CTV (cyan), bladder (yellow), rectum (magenta). A – anterior, P – posterior, H – head, F – feet

Mentions: It is imperative to select MR-compatible applicators before starting the simulation process. Current MR-compatible applicators that are commercially available include metallic applicators (i.e., titanium) and non-metallic applicators (i.e., plastic). The use of intracavitary titanium applicators for gynecologic brachytherapy is feasible at field strengths of 3T (shown in Figure 2) and lower [38], and some MRI pulse sequences such as T1w [34], proton-weighted MRI [39] and 3D pulse sequences [40] may improve applicator visualization. Although, source channel digitization has been aided with the use of X-ray markers for CT-based imaging, reliably and reproducibly fabricating MR compatible markers has been challenging [41, 42]. Additionally, the presence of applicators introduces artifacts in MRI images, and while these artifacts are very minimal with plastic applicators, they are pronounced when titanium applicators are in place. There have been several proposed methods for applicator reconstruction using MRI including the use of an MR-compatible marker [34, 43], applicator models, and/or plan libraries [10, 44]. Each of these methods have known limitations, such as the limited availability of commercial MR-compatible markers, difficulties fabricating leak-tight MR markers, and availability of models for commercial applicators [41].


Magnetic resonance imaging-guided brachytherapy for cervical cancer: initiating a program.

Owrangi AM, Prisciandaro JI, Soliman A, Ravi A, Song WY - J Contemp Brachytherapy (2015)

Comparison of CT, T1w and T2w images of a patient with a titanium ring and tandem in place. Transverse view of CT (top row), T1w (middle row) and T2w (bottom row) of a patient's pelvis with para-axial view showed in left panel and para-coronal and para-sagittal views showed in middle and right panels, respectively. The volumes are as follows: high-risk CTV (cyan), bladder (yellow), rectum (magenta). A – anterior, P – posterior, H – head, F – feet
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663219&req=5

Figure 0002: Comparison of CT, T1w and T2w images of a patient with a titanium ring and tandem in place. Transverse view of CT (top row), T1w (middle row) and T2w (bottom row) of a patient's pelvis with para-axial view showed in left panel and para-coronal and para-sagittal views showed in middle and right panels, respectively. The volumes are as follows: high-risk CTV (cyan), bladder (yellow), rectum (magenta). A – anterior, P – posterior, H – head, F – feet
Mentions: It is imperative to select MR-compatible applicators before starting the simulation process. Current MR-compatible applicators that are commercially available include metallic applicators (i.e., titanium) and non-metallic applicators (i.e., plastic). The use of intracavitary titanium applicators for gynecologic brachytherapy is feasible at field strengths of 3T (shown in Figure 2) and lower [38], and some MRI pulse sequences such as T1w [34], proton-weighted MRI [39] and 3D pulse sequences [40] may improve applicator visualization. Although, source channel digitization has been aided with the use of X-ray markers for CT-based imaging, reliably and reproducibly fabricating MR compatible markers has been challenging [41, 42]. Additionally, the presence of applicators introduces artifacts in MRI images, and while these artifacts are very minimal with plastic applicators, they are pronounced when titanium applicators are in place. There have been several proposed methods for applicator reconstruction using MRI including the use of an MR-compatible marker [34, 43], applicator models, and/or plan libraries [10, 44]. Each of these methods have known limitations, such as the limited availability of commercial MR-compatible markers, difficulties fabricating leak-tight MR markers, and availability of models for commercial applicators [41].

Bottom Line: Over the past decade, the application of magnetic resonance imaging (MRI) has increased, and there is growing evidence to suggest that improvements in accuracy of target delineation in MRI-guided brachytherapy may improve clinical outcomes in cervical cancer.It is imperative to know that the most important source of uncertainty in the treatment process is related to target delineation and therefore, the necessity of training and expertise as well as quality assurance should be emphasized.A short review of concepts and techniques that have been developed for implementation and/or improvement of workflow of a MRI-guided brachytherapy program are provided in this document, so that institutions can use and optimize some of them based on their resources to minimize their procedure times.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada ; Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA ; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.

ABSTRACT
Over the past decade, the application of magnetic resonance imaging (MRI) has increased, and there is growing evidence to suggest that improvements in accuracy of target delineation in MRI-guided brachytherapy may improve clinical outcomes in cervical cancer. To implement a high quality image guided brachytherapy program, a multidisciplinary team is required with appropriate expertise as well as an adequate patient load to ensure a sustainable program. It is imperative to know that the most important source of uncertainty in the treatment process is related to target delineation and therefore, the necessity of training and expertise as well as quality assurance should be emphasized. A short review of concepts and techniques that have been developed for implementation and/or improvement of workflow of a MRI-guided brachytherapy program are provided in this document, so that institutions can use and optimize some of them based on their resources to minimize their procedure times.

No MeSH data available.


Related in: MedlinePlus