Sci—Fri AM: Mountain — 05: Unified Optimization and Delivery of Intensity-modulated Radiation Therapy and Volume-modulated Arc Therapy

Journal Article · Fri Aug 15 04:00:00 EDT 2014 · Medical Physics

DOI:https://doi.org/10.1118/1.4894945· OSTI ID:22407702

Chen, J; Hoover, D ^[1]; MacFarlane, M ^[2]; Wong, E ^[3]

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1. Department of Oncology, Department of Medical Biophysics, London Health Science Centre, London, ON (Canada)
2. London Health Science Centre, London, ON (Canada)
3. Department of Oncology, Department of Medical Biophysics, Department of Physics and Astronomy, University of Western Ontario (Canada)

Purpose: To study the feasibility of a unified intensity-modulated arc therapy (UIMAT) that combines IMRT and VMAT optimization and delivery in order to produce efficient and superior radiation treatment plans. Methods: Inverse planning for UIMAT was prototyped on the Pinnacle treatment planning system (Philips Medical Systems). UIMAT integrates IMRT and VMAT delivery in the same arc where IMRT was delivered with gantry speed close to zero. Optimal gantry angles for the IMRT phases were selected automatically by the inverse optimization algorithm. Optimization of the VMAT phases and IMRT phases were done simultaneously using Pinnacle's direct machine parameter optimization algorithm. Five treatment plans each for prostate, head and neck, and lung were generated using our unified technique and compared with clinical VMAT or IMRT plans. Delivery verification was performed on an ArcCheck phantom (Sun Nuclear) and delivered in clinical mode on a Varian TrueBeam linear accelerator. Results: In this prototype implementation, compared to the VMAT or IMRT plans, with the plans normalized to the same dose coverage to the planning target volumes, the UIMAT plans produced improved OAR sparing for head and neck cases, while for lung and prostate cases, the dosimetric improvements for OARs were not as significant. In this proof-of-concept work, we demonstrated that a novel radiation therapy delivery technique combining VMAT and IMRT delivery in the same arc is feasible. Initial results showed UIMAT has the potential to be superior to either standard IMRT or VMAT.

• OSTI ID: 22407702
• Journal Information: Medical Physics, Journal Name: Medical Physics Journal Issue: 8 Vol. 41; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ALGORITHMS
HEAD
LINEAR ACCELERATORS
LUNGS
NECK
OPTIMIZATION
PHANTOMS
PLANNING
PROSTATE
RADIOTHERAPY