Variable circular collimator in robotic radiosurgery: a time-efficient alternative to a mini-multileaf collimator?
Purpose: Compared with many small circular beams used in CyberKnife treatments, beam's eye view-shaped fields are generally more time-efficient for dose delivery. However, beam's eye view-shaping devices, such as a mini-multileaf collimator (mMLC), are not presently available for CyberKnife, althoug...
| Publicado en: | International Journal of Radiation Oncology, Biology, Physics Vol. 81; no. 3; pp. 863 - 871 |
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| Autores principales: | , , , , , , , , , , , |
| Formato: | Journal Article |
| Publicado: |
Pergamon Press - An Imprint of Elsevier Science
Nov2011
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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=104587101&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 104587101 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: Nov2011 vid: 81 iid: 3 pid: 2410 pub: Pergamon Press - An Imprint of Elsevier Science artinfo: ui: 104587101 NLM21377286 2011311674 10.1016/j.ijrobp.2010.12.052 NLM21377286 104587101 ppf: 863 ppct: 8 formats: tig: atl: Variable circular collimator in robotic radiosurgery: a time-efficient alternative to a mini-multileaf collimator? aug: au: van de Water S Hoogeman MS Breedveld S Nuyttens JJ Schaart DR Heijmen BJ van de Water, Steven Hoogeman, Mischa S Breedveld, Sebastiaan Nuyttens, Joost J M E Schaart, Dennis R Heijmen, Ben J M affil: Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands sug: subj: Algorithms Lung Neoplasms Surgery Radiosurgery Methods Radiotherapy, Computer-Assisted Methods Robotics Methods Equipment Design Lung Neoplasms Radiography Middle Age Body Regions Radiography Radiosurgery Equipment and Supplies Radiosurgery Standards Radiation Dosage Radiotherapy, Computer-Assisted Standards Radiotherapy Methods Robotics Equipment and Supplies Robotics Standards Therapy, Computer Assisted Equipment and Supplies Therapy, Computer Assisted Methods Therapy, Computer Assisted Standards Time Factors Middle Aged: 45-64 years ab: Purpose: Compared with many small circular beams used in CyberKnife treatments, beam's eye view-shaped fields are generally more time-efficient for dose delivery. However, beam's eye view-shaping devices, such as a mini-multileaf collimator (mMLC), are not presently available for CyberKnife, although a variable-aperture collimator (Iris, 12 field diameters; 5-60 mm) is available. We investigated whether the Iris can mimic noncoplanar mMLC treatments using a limited set of principal beam orientations (nodes) to produce time-efficient treatment plans. Methods and Materials: The data from 10 lung cancer patients and the beam-orientation optimization algorithm "Cycle" were used to generate stereotactic treatment plans (3 × 20 Gy) for a CyberKnife virtually equipped with a mMLC. Typically, 10-16 favorable beam orientations were selected from 117 available robot node positions using beam's eye view-shaped fields with uniform fluence. Second, intensity-modulated Iris plans were generated by inverse optimization of nonisocentric circular candidate beams targeted from the same nodes selected in the mMLC plans. The plans were evaluated using the mean lung dose, lung volume receiving ≥20 Gy, conformality index, number of nodes, beams, and monitor units, and estimated treatment time. Results: The mMLC plans contained an average of 12 nodes and 11,690 monitor units. For a comparable mean lung dose, the Iris plans contained 12 nodes, 64 beams, and 21,990 monitor units. The estimated fraction duration was 12.2 min (range, 10.8-13.5) for the mMLC plans and 18.4 min (range, 12.9-28.5) for the Iris plans. In contrast to the mMLC plans, the treatment time for the Iris plans increased with an increasing target volume. The Iris plans were, on average, 40% longer than the corresponding mMLC plans for small targets (<80 cm(3)) and ≤121% longer for larger targets. For a comparable conformality index, similar results were obtained. Conclusion: For stereotactic lung irradiation, time-efficient and high-quality plans were obtained for robotic-controlled noncoplanar treatments using a mMLC. Iris is a time-efficient alternative for small targets, with similar or better plan quality. pubtype: Academic Journal doctype: Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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