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Title: Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer

Abstract

Purpose: The development of synthetic computed tomography (CT) (synCT) derived from magnetic resonance (MR) images supports MR-only treatment planning. We evaluated the accuracy of synCT and synCT-generated digitally reconstructed radiographs (DRRs) relative to CT and determined their performance for image guided radiation therapy (IGRT). Methods and Materials: Magnetic resonance simulation (MR-SIM) and CT simulation (CT-SIM) images were acquired of an anthropomorphic skull phantom and 12 patient brain cancer cases. SynCTs were generated using fluid attenuation inversion recovery, ultrashort echo time, and Dixon data sets through a voxel-based weighted summation of 5 tissue classifications. The DRRs were generated from the phantom synCT, and geometric fidelity was assessed relative to CT-generated DRRs through bounding box and landmark analysis. An offline retrospective analysis was conducted to register cone beam CTs (n=34) to synCTs and CTs using automated rigid registration in the treatment planning system. Planar MV and KV images (n=37) were rigidly registered to synCT and CT DRRs using an in-house script. Planar and volumetric registration reproducibility was assessed and margin differences were characterized by the van Herk formalism. Results: Bounding box and landmark analysis of phantom synCT DRRs were within 1 mm of CT DRRs. Absolute planar registration shift differences ranged from 0.0more » to 0.7 mm for phantom DRRs on all treatment platforms and from 0.0 to 0.4 mm for volumetric registrations. For patient planar registrations, the mean shift differences were 0.4 ± 0.5 mm (range, −0.6 to 1.6 mm), 0.0 ± 0.5 mm (range, −0.9 to 1.2 mm), and 0.1 ± 0.3 mm (range, −0.7 to 0.6 mm) for the superior-inferior (S-I), left-right (L-R), and anterior-posterior (A-P) axes, respectively. The mean shift differences in volumetric registrations were 0.6 ± 0.4 mm (range, −0.2 to 1.6 mm), 0.2 ± 0.4 mm (range, −0.3 to 1.2 mm), and 0.2 ± 0.3 mm (range, −0.2 to 1.2 mm) for the S-I, L-R, and A-P axes, respectively. The CT-SIM and synCT derived margins were <0.3 mm different. Conclusion: DRRs generated by synCT were in close agreement with CT-SIM. Planar and volumetric image registrations to synCT-derived targets were comparable with CT for phantom and patients. This validation is the next step toward MR-only planning for the brain.« less

Authors:
 [1];  [2]; ;  [1];  [1];  [2];  [1];  [2]
  1. Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22648747
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 95; Journal Issue: 4; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BRAIN; COMPUTERIZED TOMOGRAPHY; IMAGES; MAGNETIC MATERIALS; NEOPLASMS; PATIENTS; PHANTOMS; RADIOTHERAPY

Citation Formats

Price, Ryan G., Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, Kim, Joshua P., Zheng, Weili, Chetty, Indrin J., Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, Glide-Hurst, Carri, E-mail: churst2@hfhs.org, and Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan. Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer. United States: N. p., 2016. Web. doi:10.1016/J.IJROBP.2016.03.002.
Price, Ryan G., Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, Kim, Joshua P., Zheng, Weili, Chetty, Indrin J., Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, Glide-Hurst, Carri, E-mail: churst2@hfhs.org, & Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan. Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer. United States. doi:10.1016/J.IJROBP.2016.03.002.
Price, Ryan G., Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, Kim, Joshua P., Zheng, Weili, Chetty, Indrin J., Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan, Glide-Hurst, Carri, E-mail: churst2@hfhs.org, and Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan. Fri . "Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer". United States. doi:10.1016/J.IJROBP.2016.03.002.
@article{osti_22648747,
title = {Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer},
author = {Price, Ryan G. and Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan and Kim, Joshua P. and Zheng, Weili and Chetty, Indrin J. and Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan and Glide-Hurst, Carri, E-mail: churst2@hfhs.org and Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan},
abstractNote = {Purpose: The development of synthetic computed tomography (CT) (synCT) derived from magnetic resonance (MR) images supports MR-only treatment planning. We evaluated the accuracy of synCT and synCT-generated digitally reconstructed radiographs (DRRs) relative to CT and determined their performance for image guided radiation therapy (IGRT). Methods and Materials: Magnetic resonance simulation (MR-SIM) and CT simulation (CT-SIM) images were acquired of an anthropomorphic skull phantom and 12 patient brain cancer cases. SynCTs were generated using fluid attenuation inversion recovery, ultrashort echo time, and Dixon data sets through a voxel-based weighted summation of 5 tissue classifications. The DRRs were generated from the phantom synCT, and geometric fidelity was assessed relative to CT-generated DRRs through bounding box and landmark analysis. An offline retrospective analysis was conducted to register cone beam CTs (n=34) to synCTs and CTs using automated rigid registration in the treatment planning system. Planar MV and KV images (n=37) were rigidly registered to synCT and CT DRRs using an in-house script. Planar and volumetric registration reproducibility was assessed and margin differences were characterized by the van Herk formalism. Results: Bounding box and landmark analysis of phantom synCT DRRs were within 1 mm of CT DRRs. Absolute planar registration shift differences ranged from 0.0 to 0.7 mm for phantom DRRs on all treatment platforms and from 0.0 to 0.4 mm for volumetric registrations. For patient planar registrations, the mean shift differences were 0.4 ± 0.5 mm (range, −0.6 to 1.6 mm), 0.0 ± 0.5 mm (range, −0.9 to 1.2 mm), and 0.1 ± 0.3 mm (range, −0.7 to 0.6 mm) for the superior-inferior (S-I), left-right (L-R), and anterior-posterior (A-P) axes, respectively. The mean shift differences in volumetric registrations were 0.6 ± 0.4 mm (range, −0.2 to 1.6 mm), 0.2 ± 0.4 mm (range, −0.3 to 1.2 mm), and 0.2 ± 0.3 mm (range, −0.2 to 1.2 mm) for the S-I, L-R, and A-P axes, respectively. The CT-SIM and synCT derived margins were <0.3 mm different. Conclusion: DRRs generated by synCT were in close agreement with CT-SIM. Planar and volumetric image registrations to synCT-derived targets were comparable with CT for phantom and patients. This validation is the next step toward MR-only planning for the brain.},
doi = {10.1016/J.IJROBP.2016.03.002},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 4,
volume = 95,
place = {United States},
year = {Fri Jul 15 00:00:00 EDT 2016},
month = {Fri Jul 15 00:00:00 EDT 2016}
}