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Title: TU-FG-BRB-11: Design and Evaluation of a Robotic C-Arm CBCT System for Image-Guided Proton Therapy

Abstract

Purpose: To describe the design and performance of a ceiling-mounted robotic C-arm CBCT system for image-guided proton therapy. Methods: Uniquely different from traditional C-arm CBCT used in interventional radiology, the imaging system was designed to provide volumetric image guidance for patients treated on a 190-degree proton gantry system and a 6 degree-of-freedom (DOF) robotic patient positioner. The mounting of robotic arms to the ceiling rails, rather than gantry or nozzle, provides the flexibility in imaging locations (isocenter, iso+27cm in X, iso+100cm in Y) in the room and easier upgrade as technology advances. A kV X-ray tube and a 43×43cm flat panel imager were mounted to a rotating C-ring (87cm diameter), which is coupled to the C-arm concentrically. Both C-arm and the robotic arm remain stationary during imaging to maintain high position accuracy. Source-to-axis distance and source-to-imager distance are 100 and 150cm, respectively. A 14:1 focused anti-scatter grid and a bowtie filer are used for image acquisition. A unique automatic collimator device of 4 independent blades for adjusting field of view and reducing patient dose has also been developed. Results: Sub-millimeter position accuracy and repeatability of the robotic C-arm were measured with a laser tracker. High quality CBCT images for positioningmore » can be acquired with a weighted CTDI of 3.6mGy (head in 200° full fan mode: 100kV, 20mA, 20ms, 10fps)-8.7 mGy (pelvis in 360° half fan mode: 125kV, 42mA, 20ms, 10fps). Image guidance accuracy achieved <1mm (3D vector) with automatic 3D-3D registration for anthropomorphic head and pelvis phantoms. Since November 2015, 22 proton therapy patients have undergone daily CBCT imaging for 6 DOF positioning. Conclusion: Decoupled from gantry and nozzle, this CBCT system provides a unique solution for volumetric image guidance with half/partial proton gantry systems. We demonstrated that daily CBCT can be integrated into proton therapy for pre-treatment position verification.« less

Authors:
; ; ;  [1]; ; ; ; ; ;  [2]
  1. St. Jude Children’s Research Hospital, Memphis, TN (United States)
  2. Hitachi, Ltd., Hitachi-shi, Ibaraki-ken (Japan)
Publication Date:
OSTI Identifier:
22654004
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 43; Journal Issue: 6; Other Information: (c) 2016 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 61 RADIATION PROTECTION AND DOSIMETRY; ACCURACY; BIOMEDICAL RADIOGRAPHY; COMPUTERIZED TOMOGRAPHY; DESIGN; IMAGES; PATIENTS; POSITIONING; PROTON BEAMS; RADIOTHERAPY; X RADIATION; X-RAY TUBES

Citation Formats

Hua, C, Yao, W, Farr, J, Merchant, T, Kidani, T, Tomida, K, Ozawa, S, Nishimura, T, Fujusawa, T, and Shinagawa, R. TU-FG-BRB-11: Design and Evaluation of a Robotic C-Arm CBCT System for Image-Guided Proton Therapy. United States: N. p., 2016. Web. doi:10.1118/1.4957551.
Hua, C, Yao, W, Farr, J, Merchant, T, Kidani, T, Tomida, K, Ozawa, S, Nishimura, T, Fujusawa, T, & Shinagawa, R. TU-FG-BRB-11: Design and Evaluation of a Robotic C-Arm CBCT System for Image-Guided Proton Therapy. United States. doi:10.1118/1.4957551.
Hua, C, Yao, W, Farr, J, Merchant, T, Kidani, T, Tomida, K, Ozawa, S, Nishimura, T, Fujusawa, T, and Shinagawa, R. Wed . "TU-FG-BRB-11: Design and Evaluation of a Robotic C-Arm CBCT System for Image-Guided Proton Therapy". United States. doi:10.1118/1.4957551.
@article{osti_22654004,
title = {TU-FG-BRB-11: Design and Evaluation of a Robotic C-Arm CBCT System for Image-Guided Proton Therapy},
author = {Hua, C and Yao, W and Farr, J and Merchant, T and Kidani, T and Tomida, K and Ozawa, S and Nishimura, T and Fujusawa, T and Shinagawa, R},
abstractNote = {Purpose: To describe the design and performance of a ceiling-mounted robotic C-arm CBCT system for image-guided proton therapy. Methods: Uniquely different from traditional C-arm CBCT used in interventional radiology, the imaging system was designed to provide volumetric image guidance for patients treated on a 190-degree proton gantry system and a 6 degree-of-freedom (DOF) robotic patient positioner. The mounting of robotic arms to the ceiling rails, rather than gantry or nozzle, provides the flexibility in imaging locations (isocenter, iso+27cm in X, iso+100cm in Y) in the room and easier upgrade as technology advances. A kV X-ray tube and a 43×43cm flat panel imager were mounted to a rotating C-ring (87cm diameter), which is coupled to the C-arm concentrically. Both C-arm and the robotic arm remain stationary during imaging to maintain high position accuracy. Source-to-axis distance and source-to-imager distance are 100 and 150cm, respectively. A 14:1 focused anti-scatter grid and a bowtie filer are used for image acquisition. A unique automatic collimator device of 4 independent blades for adjusting field of view and reducing patient dose has also been developed. Results: Sub-millimeter position accuracy and repeatability of the robotic C-arm were measured with a laser tracker. High quality CBCT images for positioning can be acquired with a weighted CTDI of 3.6mGy (head in 200° full fan mode: 100kV, 20mA, 20ms, 10fps)-8.7 mGy (pelvis in 360° half fan mode: 125kV, 42mA, 20ms, 10fps). Image guidance accuracy achieved <1mm (3D vector) with automatic 3D-3D registration for anthropomorphic head and pelvis phantoms. Since November 2015, 22 proton therapy patients have undergone daily CBCT imaging for 6 DOF positioning. Conclusion: Decoupled from gantry and nozzle, this CBCT system provides a unique solution for volumetric image guidance with half/partial proton gantry systems. We demonstrated that daily CBCT can be integrated into proton therapy for pre-treatment position verification.},
doi = {10.1118/1.4957551},
journal = {Medical Physics},
number = 6,
volume = 43,
place = {United States},
year = {Wed Jun 15 00:00:00 EDT 2016},
month = {Wed Jun 15 00:00:00 EDT 2016}
}