Journal article
Rapid emission angle selection for rotating-shield brachytherapy
Medical physics (Lancaster), Vol.40(5), pp.051720-n/a
05/2013
DOI: 10.1118/1.4802750
PMCID: PMC3656952
PMID: 23635268
Abstract
Purpose:
The authors present a rapid emission angle selection (REAS) method that enables the efficient selection of the azimuthal shield angle for rotating shield brachytherapy (RSBT). The REAS method produces a Pareto curve from which a potential RSBT user can select a treatment plan that balances the tradeoff between delivery time and tumor dose conformity.
Methods:
Two cervical cancer patients were considered as test cases for the REAS method. The RSBT source considered was a Xoft AxxentTM electronic brachytherapy source, partially shielded with 0.5 mm of tungsten, which traveled inside a tandem intrauterine applicator. Three anchor RSBT plans were generated for each case using dose-volume optimization, with azimuthal shield emission angles of 90°, 180°, and 270°. The REAS method converts the anchor plans to treatment plans for all possible emission angles by combining neighboring beamlets to form beamlets for larger emission angles. Treatment plans based on exhaustive dose-volume optimization (ERVO) and exhaustive surface optimization (ERSO) were also generated for both cases. Uniform dwell-time scaling was applied to all plans such that that high-risk clinical target volume D
90 was maximized without violating the D
2cc tolerances of the rectum, bladder, and sigmoid colon.
Results:
By choosing three azimuthal emission angles out of 32 potential angles, the REAS method performs about 10 times faster than the ERVO method. By settingD
90 to 85–100 Gy10, the delivery times used by REAS generated plans are 21.0% and 19.5% less than exhaustive surface optimized plans used by the two clinical cases. By setting the delivery time budget to 5–25 and 10–30 min/fx, respectively, for two the cases, the D
90 contributions for REAS are improved by 5.8% and 5.1% compared to the ERSO plans. The ranges used in this comparison were selected in order to keep both D
90 and the delivery time within acceptable limits.
Conclusions:
The REAS method enables efficient RSBT treatment planning and delivery and provides treatment plans with comparable quality to those generated by exhaustive replanning with dose-volume optimization.
Details
- Title: Subtitle
- Rapid emission angle selection for rotating-shield brachytherapy
- Creators
- Yunlong Liu - Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242Ryan T Flynn - Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242Wenjun Yang - Department of Biomedical Engineering, University of Iowa, 1402 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242Yusung Kim - Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242Sudershan K Bhatia - Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242Wenqing Sun - Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242Xiaodong Wu - Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242
- Resource Type
- Journal article
- Publication Details
- Medical physics (Lancaster), Vol.40(5), pp.051720-n/a
- DOI
- 10.1118/1.4802750
- PMID
- 23635268
- PMCID
- PMC3656952
- NLM abbreviation
- Med Phys
- ISSN
- 0094-2405
- eISSN
- 2473-4209
- Number of pages
- 12
- Grant note
- CCF-0844765 / NSF K25-CA123112 / NIH
- Language
- English
- Date published
- 05/2013
- Academic Unit
- Electrical and Computer Engineering; Radiation Oncology
- Record Identifier
- 9984046933502771
Metrics
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