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BioMed Research International
Volume 2013 (2013), Article ID 391021, 8 pages
http://dx.doi.org/10.1155/2013/391021
Review Article

What Would Be the Most Appropriate Ratio in the Setting of Stereotactic Body Radiation Therapy for Early Stage Non-Small Cell Lung Cancer

1Department of Radiation Oncology, West Virginia University, Medical Center Dr., Morgantown, WV 26506, USA
2Biostatistics Core, Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV 26506, USA
3Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
4Department of Human Oncology, University of Wisconsin, Madison, WI 53792, USA
5Westat-An Employee-Owned Research Corporation, Rockville, MD 20850, USA
6Department of Radiation Oncology, University of Arizona, Tucson, AZ 85724, USA
7Department of Medical Physics, University of Wisconsin, Madison, WI 53792, USA
8Department of Physics, Northern Illinois University, DeKalb, IL 60115, USA

Received 8 May 2013; Accepted 25 September 2013

Academic Editor: Rumiana Koynova

Copyright © 2013 Alexander Chi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We hypothesize that the correlation between the radiation dose expressed as the biologically effective dose (BED) and the clinical endpoints will correlate better as the value of the ratio is increased to >10 Gy, which theoretically minimizes the overestimation of the dose potency associated with the linear quadratic (LQ) formula in the setting of stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC). A search was conducted in the PubMed electronic databases in August 2011. In the studies analyzed, increasing the ratio is associated with an increase in the strength of the correlation between isocenter BED and local control, especially in the studies with median followup of ≥24 months, for which Spearman’s correlation coefficients of 0.74–0.76 were achieved for of 20 Gy, 30 Gy, and 50 Gy (  0.007–0.008). A trend toward statistical significance was observed for the correlation of isocenter BED and the 2-year overall survival when an of 20 Gy was used approached statistical significance ( ). Our results suggest that an  Gy may be more appropriate for the prediction of dose response in the setting of lung SBRT.