Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization
<p>Abstract</p> <p>Background</p> <p>2-step intensity modulated arc therapy (IMAT) is a simplified IMAT technique which delivers the treatment over typically two continuous gantry rotations. The aim of this work was to implement the technique into a computerized treatme...
| Huvudupphovsmän: | , , |
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| Materialtyp: | Artikel |
| Språk: | English |
| Publicerad: |
BMC
2011-06-01
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| Serie: | Radiation Oncology |
| Länkar: | http://www.ro-journal.com/content/6/1/57 |
| _version_ | 1831833918526980096 |
|---|---|
| author | Meyer Juergen Chew Theam Sun Jidi |
| author_facet | Meyer Juergen Chew Theam Sun Jidi |
| author_sort | Meyer Juergen |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>2-step intensity modulated arc therapy (IMAT) is a simplified IMAT technique which delivers the treatment over typically two continuous gantry rotations. The aim of this work was to implement the technique into a computerized treatment planning system and to develop an approach to optimize the segment weights and widths.</p> <p>Methods</p> <p>2-step IMAT was implemented into the Prism treatment planning system. A graphical user interface was developed to generate the plan segments automatically based on the anatomy in the beam's-eye-view. The segment weights and widths of 2-step IMAT plans were subsequently determined in Matlab using a dose-volume based optimization process. The implementation was tested on a geometric phantom with a horseshoe shaped target volume and then applied to a clinical paraspinal tumour case.</p> <p>Results</p> <p>The phantom study verified the correctness of the implementation and showed a considerable improvement over a non-modulated arc. Further improvements in the target dose uniformity after the optimization of 2-step IMAT plans were observed for both the phantom and clinical cases. For the clinical case, optimizing the segment weights and widths reduced the maximum dose from 114% of the prescribed dose to 107% and increased the minimum dose from 87% to 97%. This resulted in an improvement in the homogeneity index of the target dose for the clinical case from 1.31 to 1.11. Additionally, the high dose volume V<sub>105 </sub>was reduced from 57% to 7% while the maximum dose in the organ-at-risk was decreased by 2%.</p> <p>Conclusions</p> <p>The intuitive and automatic planning process implemented in this study increases the prospect of the practical use of 2-step IMAT. This work has shown that 2-step IMAT is a viable technique able to achieve highly conformal plans for concave target volumes with the optimization of the segment weights and widths. Future work will include planning comparisons of the 2-step IMAT implementation with fixed gantry intensity modulated radiotherapy (IMRT) and commercial IMAT implementations.</p> |
| first_indexed | 2024-12-23T04:02:21Z |
| format | Article |
| id | doaj.art-a538af20fda14a6bb6b74b15e74b45b4 |
| institution | Directory Open Access Journal |
| issn | 1748-717X |
| language | English |
| last_indexed | 2024-12-23T04:02:21Z |
| publishDate | 2011-06-01 |
| publisher | BMC |
| record_format | Article |
| series | Radiation Oncology |
| spelling | doaj.art-a538af20fda14a6bb6b74b15e74b45b42022-12-21T18:00:42ZengBMCRadiation Oncology1748-717X2011-06-01615710.1186/1748-717X-6-57Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimizationMeyer JuergenChew TheamSun Jidi<p>Abstract</p> <p>Background</p> <p>2-step intensity modulated arc therapy (IMAT) is a simplified IMAT technique which delivers the treatment over typically two continuous gantry rotations. The aim of this work was to implement the technique into a computerized treatment planning system and to develop an approach to optimize the segment weights and widths.</p> <p>Methods</p> <p>2-step IMAT was implemented into the Prism treatment planning system. A graphical user interface was developed to generate the plan segments automatically based on the anatomy in the beam's-eye-view. The segment weights and widths of 2-step IMAT plans were subsequently determined in Matlab using a dose-volume based optimization process. The implementation was tested on a geometric phantom with a horseshoe shaped target volume and then applied to a clinical paraspinal tumour case.</p> <p>Results</p> <p>The phantom study verified the correctness of the implementation and showed a considerable improvement over a non-modulated arc. Further improvements in the target dose uniformity after the optimization of 2-step IMAT plans were observed for both the phantom and clinical cases. For the clinical case, optimizing the segment weights and widths reduced the maximum dose from 114% of the prescribed dose to 107% and increased the minimum dose from 87% to 97%. This resulted in an improvement in the homogeneity index of the target dose for the clinical case from 1.31 to 1.11. Additionally, the high dose volume V<sub>105 </sub>was reduced from 57% to 7% while the maximum dose in the organ-at-risk was decreased by 2%.</p> <p>Conclusions</p> <p>The intuitive and automatic planning process implemented in this study increases the prospect of the practical use of 2-step IMAT. This work has shown that 2-step IMAT is a viable technique able to achieve highly conformal plans for concave target volumes with the optimization of the segment weights and widths. Future work will include planning comparisons of the 2-step IMAT implementation with fixed gantry intensity modulated radiotherapy (IMRT) and commercial IMAT implementations.</p>http://www.ro-journal.com/content/6/1/57 |
| spellingShingle | Meyer Juergen Chew Theam Sun Jidi Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization Radiation Oncology |
| title | Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization |
| title_full | Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization |
| title_fullStr | Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization |
| title_full_unstemmed | Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization |
| title_short | Two-step intensity modulated arc therapy (2-step IMAT) with segment weight and width optimization |
| title_sort | two step intensity modulated arc therapy 2 step imat with segment weight and width optimization |
| url | http://www.ro-journal.com/content/6/1/57 |
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