Indian Journal of Oncology and Radiation Biology

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Effect of Applicator Reconstruction Shifting on Dosimetric Dose-Volume Histogram Parameters during Magnetic Resonance Imaging in Brachytherapy for Cervical Cancer Patients


Affiliations
1 Department of Radiology, King Chulalongkorn Memorial Hospital, 1873, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
2 Department of Radiology, Chulalongkorn University, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
 

Objective: This study observed the dose-volume histogram (DVH) parameter changes caused by applicator shifting that result from patient movement during image acquisition for magnetic resonance imaging guided brachytherapy for cervical cancer patients.

Materials and Methods: Nine cervical cancer plans with insertion of a Fletcher computed tomography (CT)/magnetic resonance (MR) applicator were retrospectively studied. The MR sequences were T2 fast spin echo on parasagittal, para-axial, and para-coronal planes, respectively. The applicator library was used for applicator reconstruction in each image data set. The tip of the applicator (2 ovoids + 1 tandem) was identified, and the difference from the reference image (axial view) was recorded. The DVH parameters were as follows: D90 of high-risk clinical target volume (HR-CTV) and D2cc of the bladder and rectum for each image data set were compared with the reference image.

Results: The tandem showed less applicator shift on the coronal plane than the reference image. The applicator shifts for tandem were 0.0 ± 0.4, 0.0 ± 1.0, and -0.5 ± 1.0 mm in the left-right, superior-inferior, and anterior-posterior directions, respectively. The mean percentage dose differences in DVH parameters on the coronal and sagittal planes were 3.04% and 1.23% for D90 of HR-CTV, 2.73% and 3.88% for D2cc of the bladder, and 2.60% and 3.49% for D2cc of the rectum, respectively.

Conclusion: An image acquisition time of approximately 15 minutes for three-dimensional MR brachytherapy provided a mean applicator reconstruction shift within 1.3 mm, with minor effects on the DVH parameter of approximately 3%.


Keywords

Applicator Reconstruction, MRI-Brachytherapy, Uncertainty, Applicator Library.
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  • Source: annual survey 2013-2014. http://www.thastro.org/index.php/2014-03-27-01-07-52. Date accessed: 01/02/2016.

  • ICRU Report 38. Dose and volume specification for reporting intracavitary therapy in gynecology. International Commission on Radiation Units and Measurement. Bethesda, Maryland, 1985.

  • R. Potter, E.V. Limbergen, N. Gerstner, A. Wambersie. Survey of the use of the ICRU 38 in recording and reporting cervical cancer brachytherapy. Radiotherapy and Oncology. 2001; 58(1), 11-18.

  • J. Dimopoulos, P. Petrow, K. Tanderup, P. Petric, D. Berger, C. Kirisits . Recommendations from gynecological (GYN) GEC-ESTRO working group (IV): Basic principles and parameters for MR imaging within the frame of image based adaptive cervix cancer brachytherapy. Radiotherapy and Oncology. 2012; 103(1), 113-122.

  • T.P. Hellebust, C. Kirisits, D. Berger, Perez-Calatayud, M. Brabandere, A.A. Leeuw. Recommendations from gynaecological (GYN) GEC-ESTRO working group: Considerations and pitfalls in commissioning and applicator reconstruction in 3D image-based treatment planning of cervix cancer brachytherapy. Radiotherapy and Oncology. 2010; 96(2), 153-160.

  • E.M. Kerkhof, R.W. van der Put, B.W. Raaymakers, U.A. van der Heide, I.M. Jurgenliemk-Schulz, J.J.W. Lagendijk. Intrafraction of the primary CTV in patients with cervical cancer: an assessment by repeated MR imaging. Radiotherapy and Oncology. 2008; 88, S108.

  • J. Schindel, W. Zhang, S.K. Bhatia, W. Sun, Y. Kim. Dosimetric impacts of applicator displacements and applicator reconstruction-uncertainties on 3D image-guided brachytherapy for cervical cancer. Journal of Contemporary Brachytherapy. 2013; 5(4), 250-257.

  • K. Tanderup, T.P. Hellebust, S. Lang, J. Granfeldt, R. Potter, J.C. Lindegaard. Consequences of random and systematic reconstruction uncertainties in 3D image based brachytherapy in cervical cancer. Radiotherapy and Oncology. 2008; 89, 156-163.

  • K. Tenderup, N. Nesvacil, R. Potter, C. Kirisits. Uncertainty in image guided adaptive cervix cancer brachytherapy: Impact on planning and prescription. Radiotherapy and Oncology. 2013; 107, 1-5.

  • A.A.C. De Leeuw, M.A. Moerland, C. Nomden, R.H.A. Tersteeg, J.M. Roesink, I.M. Jurgenliemk-Schulz. Applicator reconstruction and applicator shifts in 3D-MR-based PDR brachytherapy of cervical cancer. Radiotherapy and Oncology. 2009; 93(2), 341-346.


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  • Effect of Applicator Reconstruction Shifting on Dosimetric Dose-Volume Histogram Parameters during Magnetic Resonance Imaging in Brachytherapy for Cervical Cancer Patients

Abstract Views: 570  |  PDF Views: 218

Authors

P. Oonsiri
Department of Radiology, King Chulalongkorn Memorial Hospital, 1873, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
P. Alisanant
Department of Radiology, King Chulalongkorn Memorial Hospital, 1873, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
W. Mephiew
Department of Radiology, King Chulalongkorn Memorial Hospital, 1873, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
S. Suriyapee
Department of Radiology, Chulalongkorn University, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
N. Amornwichet
Department of Radiology, Chulalongkorn University, Rama IV Road, Pathumwan, Bangkok 10330, Thailand

Abstract


Objective: This study observed the dose-volume histogram (DVH) parameter changes caused by applicator shifting that result from patient movement during image acquisition for magnetic resonance imaging guided brachytherapy for cervical cancer patients.

Materials and Methods: Nine cervical cancer plans with insertion of a Fletcher computed tomography (CT)/magnetic resonance (MR) applicator were retrospectively studied. The MR sequences were T2 fast spin echo on parasagittal, para-axial, and para-coronal planes, respectively. The applicator library was used for applicator reconstruction in each image data set. The tip of the applicator (2 ovoids + 1 tandem) was identified, and the difference from the reference image (axial view) was recorded. The DVH parameters were as follows: D90 of high-risk clinical target volume (HR-CTV) and D2cc of the bladder and rectum for each image data set were compared with the reference image.

Results: The tandem showed less applicator shift on the coronal plane than the reference image. The applicator shifts for tandem were 0.0 ± 0.4, 0.0 ± 1.0, and -0.5 ± 1.0 mm in the left-right, superior-inferior, and anterior-posterior directions, respectively. The mean percentage dose differences in DVH parameters on the coronal and sagittal planes were 3.04% and 1.23% for D90 of HR-CTV, 2.73% and 3.88% for D2cc of the bladder, and 2.60% and 3.49% for D2cc of the rectum, respectively.

Conclusion: An image acquisition time of approximately 15 minutes for three-dimensional MR brachytherapy provided a mean applicator reconstruction shift within 1.3 mm, with minor effects on the DVH parameter of approximately 3%.


Keywords


Applicator Reconstruction, MRI-Brachytherapy, Uncertainty, Applicator Library.

References