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Title: Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring

Abstract

Purpose: To develop a new approach for interobserver variability analysis. Methods and Materials: Eight radiation oncologists specializing in breast cancer radiation therapy delineated a patient's left breast “from scratch” and from a template that was generated using deformable image registration. Three of the radiation oncologists had previously received training in Radiation Therapy Oncology Group consensus contouring for breast cancer atlas. The simultaneous truth and performance level estimation algorithm was applied to the 8 contours delineated “from scratch” to produce a group consensus contour. Individual Jaccard scores were fitted to a beta distribution model. We also applied this analysis to 2 or more patients, which were contoured by 9 breast radiation oncologists from 8 institutions. Results: The beta distribution model had a mean of 86.2%, standard deviation (SD) of ±5.9%, a skewness of −0.7, and excess kurtosis of 0.55, exemplifying broad interobserver variability. The 3 RTOG-trained physicians had higher agreement scores than average, indicating that their contours were close to the group consensus contour. One physician had high sensitivity but lower specificity than the others, which implies that this physician tended to contour a structure larger than those of the others. Two other physicians had low sensitivity but specificity similar tomore » the others, which implies that they tended to contour a structure smaller than the others. With this information, they could adjust their contouring practice to be more consistent with others if desired. When contouring from the template, the beta distribution model had a mean of 92.3%, SD ± 3.4%, skewness of −0.79, and excess kurtosis of 0.83, which indicated a much better consistency among individual contours. Similar results were obtained for the analysis of 2 additional patients. Conclusions: The proposed statistical approach was able to measure interobserver variability quantitatively and to identify individuals who tended to contour differently from the others. The information could be useful as feedback to improve contouring consistency.« less

Authors:
 [1]; ; ; ; ; ;  [2]; ; ;  [1];  [3];  [1]
  1. Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)
  2. Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)
  3. Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)
Publication Date:
OSTI Identifier:
22416566
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 89; Journal Issue: 1; Other Information: Copyright (c) 2014 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; ALGORITHMS; MAMMARY GLANDS; MEDICAL PERSONNEL; NEOPLASMS; PATIENTS; RADIOTHERAPY; SENSITIVITY; SPECIFICITY

Citation Formats

Yang, Jinzhong, Woodward, Wendy A., Reed, Valerie K., Strom, Eric A., Perkins, George H., Tereffe, Welela, Buchholz, Thomas A., Zhang, Lifei, Balter, Peter, Court, Laurence E., Li, X. Allen, Dong, Lei, and Scripps Proton Therapy Center, San Diego, California. Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring. United States: N. p., 2014. Web. doi:10.1016/J.IJROBP.2014.01.010.
Yang, Jinzhong, Woodward, Wendy A., Reed, Valerie K., Strom, Eric A., Perkins, George H., Tereffe, Welela, Buchholz, Thomas A., Zhang, Lifei, Balter, Peter, Court, Laurence E., Li, X. Allen, Dong, Lei, & Scripps Proton Therapy Center, San Diego, California. Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring. United States. https://doi.org/10.1016/J.IJROBP.2014.01.010
Yang, Jinzhong, Woodward, Wendy A., Reed, Valerie K., Strom, Eric A., Perkins, George H., Tereffe, Welela, Buchholz, Thomas A., Zhang, Lifei, Balter, Peter, Court, Laurence E., Li, X. Allen, Dong, Lei, and Scripps Proton Therapy Center, San Diego, California. 2014. "Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring". United States. https://doi.org/10.1016/J.IJROBP.2014.01.010.
@article{osti_22416566,
title = {Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring},
author = {Yang, Jinzhong and Woodward, Wendy A. and Reed, Valerie K. and Strom, Eric A. and Perkins, George H. and Tereffe, Welela and Buchholz, Thomas A. and Zhang, Lifei and Balter, Peter and Court, Laurence E. and Li, X. Allen and Dong, Lei and Scripps Proton Therapy Center, San Diego, California},
abstractNote = {Purpose: To develop a new approach for interobserver variability analysis. Methods and Materials: Eight radiation oncologists specializing in breast cancer radiation therapy delineated a patient's left breast “from scratch” and from a template that was generated using deformable image registration. Three of the radiation oncologists had previously received training in Radiation Therapy Oncology Group consensus contouring for breast cancer atlas. The simultaneous truth and performance level estimation algorithm was applied to the 8 contours delineated “from scratch” to produce a group consensus contour. Individual Jaccard scores were fitted to a beta distribution model. We also applied this analysis to 2 or more patients, which were contoured by 9 breast radiation oncologists from 8 institutions. Results: The beta distribution model had a mean of 86.2%, standard deviation (SD) of ±5.9%, a skewness of −0.7, and excess kurtosis of 0.55, exemplifying broad interobserver variability. The 3 RTOG-trained physicians had higher agreement scores than average, indicating that their contours were close to the group consensus contour. One physician had high sensitivity but lower specificity than the others, which implies that this physician tended to contour a structure larger than those of the others. Two other physicians had low sensitivity but specificity similar to the others, which implies that they tended to contour a structure smaller than the others. With this information, they could adjust their contouring practice to be more consistent with others if desired. When contouring from the template, the beta distribution model had a mean of 92.3%, SD ± 3.4%, skewness of −0.79, and excess kurtosis of 0.83, which indicated a much better consistency among individual contours. Similar results were obtained for the analysis of 2 additional patients. Conclusions: The proposed statistical approach was able to measure interobserver variability quantitatively and to identify individuals who tended to contour differently from the others. The information could be useful as feedback to improve contouring consistency.},
doi = {10.1016/J.IJROBP.2014.01.010},
url = {https://www.osti.gov/biblio/22416566}, journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 1,
volume = 89,
place = {United States},
year = {Thu May 01 00:00:00 EDT 2014},
month = {Thu May 01 00:00:00 EDT 2014}
}