title: A Simulation Study of a Radiofrequency Localization System for Tracking Patient Motion in Radiotherapy.
abstract: One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a localization estimate and angular resolution of sensors (signal receivers) in a simulated room. The results indicate that the external sensor needs an angular resolution of about 0.03 degrees to achieve millimeter-level localization accuracy in a treatment room. This fundamental study of a novel RF localization system offers the groundwork to design a radiotherapy-compatible patient positioning system for active motion compensation.
authors.affiliation: Radiation Oncology, Medical Physics Graduate Program, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA. ostynmr@vcu.edu.|Department of Mechanical and Nuclear Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA. ostynmr@vcu.edu.
authors.forename: Mark
authors.initials: M
authors.lastname: Ostyn
authors.affiliation: Radiation Oncology, Medical Physics Graduate Program, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA. siyong.kim@vcuhealth.org.
authors.forename: Siyong
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Mechanical and Nuclear Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA. whyeo@vcu.edu.|Center for Rehabilitation Science and Engineering, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA. whyeo@vcu.edu.
authors.forename: Woon-Hong
authors.initials: WH
authors.lastname: Yeo
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006801:Humans; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009068:Movement / Q000502:physiology / Q000528:radiation effects*; D009369:Neoplasms / Q000503:physiopathology / Q000532:radiotherapy*; D019047:Phantoms, Imaging; D000078702:Radiofrequency Therapy; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage
keywords: Monte Carlo simulation; angulation; direction of arrival; intrafraction motion; localization; radiotherapy