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Title: Reproducibility of Tumor Motion Probability Distribution Function in Stereotactic Body Radiation Therapy of Lung Cancer

Abstract

Purpose: To evaluate the reproducibility of tumor motion probability distribution function (PDF) in stereotactic body radiation therapy (SBRT) of lung cancer using cine megavoltage (MV) images. Methods and Materials: Cine MV images of 20 patients acquired during three-dimensional conformal (6-11 beams) SBRT treatments were retrospectively analyzed to extract tumor motion trajectories. For each patient, tumor motion PDFs were generated per fraction (PDF{sub n}) using three selected 'usable' beams. Patients without at least three usable beams were excluded from the study. Fractional PDF reproducibility (R{sub n}) was calculated as the Dice similarity coefficient between PDF{sub n} to a 'ground-truth' PDF (PDF{sub g}), which was generated using the selected beams of all fractions. The mean of R{sub n}, labeled as R{sub m}, was calculated for each patient and correlated to the patient's mean tumor motion rang (A{sub m}). Change of R{sub m} during the course of SBRT treatments was also evaluated. Intra- and intersubject coefficient of variation (CV) of R{sub m} and A{sub m} were determined. Results: Thirteen patients had at least three usable beams and were analyzed. The mean of R{sub m} was 0.87 (range, 0.84-0.95). The mean of A{sub m} was 3.18 mm (range, 0.46-7.80 mm). R{sub m} was foundmore » to decrease as A{sub m} increases following an equation of R{sub m} = 0.17e{sup -0.9Am} + 0.84. R{sub m} also decreased slightly throughout the course of treatments. Intersubject CV of R{sub m} (0.05) was comparable to intrasubject CV of R{sub m} (range, 0.02-0.09); intersubject CV of A{sub m} (0.73) was significantly greater than intrasubject CV of A{sub m} (range, 0.09-0.24). Conclusions: Tumor motion PDF can be determined using cine MV images acquired during the treatments. The reproducibility of lung tumor motion PDF decreased exponentially as the tumor motion range increased and decreased slightly throughout the course of the treatments.« less

Authors:
 [1];  [2];  [3]; ;  [1];  [1];  [2];  [1];  [2]
  1. Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)
  2. (United States)
  3. Department of Radiation Oncology, National Cancer Centre (Singapore)
Publication Date:
OSTI Identifier:
22149613
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 84; Journal Issue: 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; DISTRIBUTION FUNCTIONS; LUNGS; NEOPLASMS; PATIENTS; PROBABILITY; RADIOTHERAPY; VARIATIONS

Citation Formats

Zhang Fan, Medical Physics Graduate Program, Duke University, Durham, North Carolina, Hu Jing, Kelsey, Chris R., Yoo, David, Yin Fangfang, Medical Physics Graduate Program, Duke University, Durham, North Carolina, Cai Jing, E-mail: jing.cai@duke.edu, and Medical Physics Graduate Program, Duke University, Durham, North Carolina. Reproducibility of Tumor Motion Probability Distribution Function in Stereotactic Body Radiation Therapy of Lung Cancer. United States: N. p., 2012. Web. doi:10.1016/J.IJROBP.2012.01.037.
Zhang Fan, Medical Physics Graduate Program, Duke University, Durham, North Carolina, Hu Jing, Kelsey, Chris R., Yoo, David, Yin Fangfang, Medical Physics Graduate Program, Duke University, Durham, North Carolina, Cai Jing, E-mail: jing.cai@duke.edu, & Medical Physics Graduate Program, Duke University, Durham, North Carolina. Reproducibility of Tumor Motion Probability Distribution Function in Stereotactic Body Radiation Therapy of Lung Cancer. United States. doi:10.1016/J.IJROBP.2012.01.037.
Zhang Fan, Medical Physics Graduate Program, Duke University, Durham, North Carolina, Hu Jing, Kelsey, Chris R., Yoo, David, Yin Fangfang, Medical Physics Graduate Program, Duke University, Durham, North Carolina, Cai Jing, E-mail: jing.cai@duke.edu, and Medical Physics Graduate Program, Duke University, Durham, North Carolina. Thu . "Reproducibility of Tumor Motion Probability Distribution Function in Stereotactic Body Radiation Therapy of Lung Cancer". United States. doi:10.1016/J.IJROBP.2012.01.037.
@article{osti_22149613,
title = {Reproducibility of Tumor Motion Probability Distribution Function in Stereotactic Body Radiation Therapy of Lung Cancer},
author = {Zhang Fan and Medical Physics Graduate Program, Duke University, Durham, North Carolina and Hu Jing and Kelsey, Chris R. and Yoo, David and Yin Fangfang and Medical Physics Graduate Program, Duke University, Durham, North Carolina and Cai Jing, E-mail: jing.cai@duke.edu and Medical Physics Graduate Program, Duke University, Durham, North Carolina},
abstractNote = {Purpose: To evaluate the reproducibility of tumor motion probability distribution function (PDF) in stereotactic body radiation therapy (SBRT) of lung cancer using cine megavoltage (MV) images. Methods and Materials: Cine MV images of 20 patients acquired during three-dimensional conformal (6-11 beams) SBRT treatments were retrospectively analyzed to extract tumor motion trajectories. For each patient, tumor motion PDFs were generated per fraction (PDF{sub n}) using three selected 'usable' beams. Patients without at least three usable beams were excluded from the study. Fractional PDF reproducibility (R{sub n}) was calculated as the Dice similarity coefficient between PDF{sub n} to a 'ground-truth' PDF (PDF{sub g}), which was generated using the selected beams of all fractions. The mean of R{sub n}, labeled as R{sub m}, was calculated for each patient and correlated to the patient's mean tumor motion rang (A{sub m}). Change of R{sub m} during the course of SBRT treatments was also evaluated. Intra- and intersubject coefficient of variation (CV) of R{sub m} and A{sub m} were determined. Results: Thirteen patients had at least three usable beams and were analyzed. The mean of R{sub m} was 0.87 (range, 0.84-0.95). The mean of A{sub m} was 3.18 mm (range, 0.46-7.80 mm). R{sub m} was found to decrease as A{sub m} increases following an equation of R{sub m} = 0.17e{sup -0.9Am} + 0.84. R{sub m} also decreased slightly throughout the course of treatments. Intersubject CV of R{sub m} (0.05) was comparable to intrasubject CV of R{sub m} (range, 0.02-0.09); intersubject CV of A{sub m} (0.73) was significantly greater than intrasubject CV of A{sub m} (range, 0.09-0.24). Conclusions: Tumor motion PDF can be determined using cine MV images acquired during the treatments. The reproducibility of lung tumor motion PDF decreased exponentially as the tumor motion range increased and decreased slightly throughout the course of the treatments.},
doi = {10.1016/J.IJROBP.2012.01.037},
journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 3,
volume = 84,
place = {United States},
year = {2012},
month = {11}
}