Choreographing couch and collimator in volumetric modulated arc therapy.
Purpose: To design and optimize trajectory-based, noncoplanar subarcs for volumetric modulated arc therapy (VMAT) deliverable on both Varian TrueBEAM system and traditional accelerators; and to investigate their potential advantages for treating central nervous system (CNS) tumors.Methods and Materi...
| Publicado en: | International Journal of Radiation Oncology, Biology, Physics Vol. 80; no. 4; pp. 1238 - 1248 |
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| Autores principales: | , , , , , , , , , , , , , , , , , |
| Formato: | research Journal Article |
| Publicado: |
Pergamon Press - An Imprint of Elsevier Science
Jul2011
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=104672400&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 104672400 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 03603016 1ZQ jtl: International Journal of Radiation Oncology, Biology, Physics issn: 03603016 maglogo: N pubinfo: dt: Jul2011 vid: 80 iid: 4 pid: 2410 pub: Pergamon Press - An Imprint of Elsevier Science artinfo: ui: 104672400 NLM21377811 2011237480 10.1016/j.ijrobp.2010.10.016 NLM21377811 104672400 ppf: 1238 ppct: 10 formats: tig: atl: Choreographing couch and collimator in volumetric modulated arc therapy. aug: au: Yang Y Zhang P Happersett L Xiong J Yang J Chan M Beal K Mageras G Hunt M Yang, Yingli Zhang, Pengpeng Happersett, Laura Xiong, Jianping Yang, Jie Chan, Maria Beal, Kathryn Mageras, Gig Hunt, Margie affil: Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA sug: subj: Central Nervous System Neoplasms Radiotherapy Body Regions Radiography Particle Accelerators Equipment and Supplies Radiotherapy, Computer-Assisted Equipment and Supplies Radiotherapy, Conformal Equipment and Supplies Central Nervous System Neoplasms Radiography Physical Sciences Factor Analysis Radiotherapy, Computer-Assisted Methods Radiotherapy, Conformal Methods Retrospective Design ab: Purpose: To design and optimize trajectory-based, noncoplanar subarcs for volumetric modulated arc therapy (VMAT) deliverable on both Varian TrueBEAM system and traditional accelerators; and to investigate their potential advantages for treating central nervous system (CNS) tumors.Methods and Materials: To guide the computerized selection of beam trajectories consisting of simultaneous couch, gantry, and collimator motion, a score function was implemented to estimate the geometric overlap between targets and organs at risk for each couch/gantry angle combination. An initial set of beam orientations is obtained as a function of couch and gantry angle, according to a minimum search of the score function excluding zones of collision. This set is grouped into multiple continuous and extended subarcs subject to mechanical limitations using a hierarchical clustering algorithm. After determination of couch/gantry trajectories, a principal component analysis finds the collimator angle at each beam orientation that minimizes residual target-organ at risk overlaps. An in-house VMAT optimization algorithm determines the optimal multileaf collimator position and monitor units for control points within each subarc. A retrospective study of 10 CNS patients compares the proposed method of VMAT trajectory with dynamic gantry, leaves, couch, and collimator motion (Tra-VMAT); a standard noncoplanar VMAT with no couch/collimator motion within subarcs (Std-VMAT); and noncoplanar intensity-modulated radiotherapy (IMRT) plans that were clinically used.Results: Tra-VMAT provided improved target dose conformality and lowered maximum dose to brainstem, optic nerves, and chiasm by 7.7%, 1.1%, 2.3%, and 1.7%, respectively, compared with Std-VMAT. Tra-VMAT provided higher planning target volume minimum dose and reduced maximum dose to chiasm, optic nerves, and cochlea by 6.2%, 1.3%, 6.3%, and 8.4%, respectively, and reduced cochlea mean dose by 8.7%, compared with IMRT. Tra-VMAT averaged beam-on time was comparable to Std-VMAT but significantly (45%) less than IMRT.Conclusion: Optimized couch, gantry, and collimator trajectories may be integrated into VMAT with improved mechanical flexibility and may provide better dosimetric properties and improved efficiency in the treatment of CNS tumors. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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