TY - JOUR
T1 - Current clinical coverage of Radiation Therapy Oncology Group-defined target volumes for postmastectomy radiation therapy
AU - Fontanilla, Hiral P.
AU - Woodward, Wendy A.
AU - Lindberg, Mary E.
AU - Kanke, James E.
AU - Arora, Gurpreet
AU - Durbin, Rosalind R.
AU - Yu, Tse Kuan
AU - Zhang, Lifei
AU - Sharp, Hadley J.
AU - Strom, Eric A.
AU - Salehpour, Mohammad
AU - White, Julia
AU - Buchholz, Thomas A.
AU - Dong, Lei
N1 - Funding Information:
Sources of support: This study was supported in part by a grant from Varian Medical Systems, Palo Alto, CA, and by Institutional Research Training Grant T32CA77050 and MD Anderson's Cancer Center Support Grant CA016672 from the National Cancer Institute.
PY - 2012/7
Y1 - 2012/7
N2 - Purpose: The Radiation Therapy Oncology Group (RTOG) has published consensus guidelines for contouring relevant anatomy for postmastectomy radiation therapy (RT). How these contours relate to current treatment practices is unknown. We analyzed the dose-volume histograms (DVHs) for these contours using current clinical practice at University of Texas MD Anderson Cancer Center and compared them with the proposed treatment plans to treat RTOG-defined targets to full dose. Methods and Materials: We retrospectively analyzed treatment plans for 20 consecutive women treated with postmastectomy RT for which the treatment targets were the chest wall (CW), level III axilla (Ax3), supraclavicular (SCV), and internal mammary (IM) nodes. The RTOG consensus definitions were used to contour the following anatomic structures: CW; level I, II, and III axillary nodes (Ax1, Ax2, Ax3); SCV; IM; and heart (H). DVHs for these contours and the ipsilateral lung were generated from clinically designed treatment that had actually been delivered to each patient. For comparison regarding dose to normal tissue, new treatment plans were generated with the goal of covering 95% of the anatomic contours to 45 Gy. Results: The prescribed dose was 50 Gy in each case. The mean percent of volumes that received 45 Gy (V 45) for the RTOG guideline-based contours were CW 74%, Ax1 84%, Ax2 88%, Ax3 96%, SCV 84%, and IM 80%. Mean heart V 10 values were 11% for treatment of left-sided tumors and 6% for right-sided tumors. Mean ipsilateral lung V 20 values were 28% for left-sided tumors and 34% for right-sided tumors. For the contour-based plans, mean V 45 values were CW 94%, Ax1 95%, Ax2 97%, Ax3 98%, SCV 98%, and IM 85%. Mean heart V 10 values were 14% for treatment of left-sided tumors and 12% for right-sided tumors. Mean ipsilateral lung V 20 values were 32% for left-sided tumors and 45% for right-sided tumors. Conclusions: Clinically derived treatment plans, which have proven efficacy and are the current standard, cover 74% to 96% of the anatomy-based RTOG consensus volumes to the prescription dose. This discrepancy should be considered if treatment planning protocol guidelines are designed to incorporate these new definitions.
AB - Purpose: The Radiation Therapy Oncology Group (RTOG) has published consensus guidelines for contouring relevant anatomy for postmastectomy radiation therapy (RT). How these contours relate to current treatment practices is unknown. We analyzed the dose-volume histograms (DVHs) for these contours using current clinical practice at University of Texas MD Anderson Cancer Center and compared them with the proposed treatment plans to treat RTOG-defined targets to full dose. Methods and Materials: We retrospectively analyzed treatment plans for 20 consecutive women treated with postmastectomy RT for which the treatment targets were the chest wall (CW), level III axilla (Ax3), supraclavicular (SCV), and internal mammary (IM) nodes. The RTOG consensus definitions were used to contour the following anatomic structures: CW; level I, II, and III axillary nodes (Ax1, Ax2, Ax3); SCV; IM; and heart (H). DVHs for these contours and the ipsilateral lung were generated from clinically designed treatment that had actually been delivered to each patient. For comparison regarding dose to normal tissue, new treatment plans were generated with the goal of covering 95% of the anatomic contours to 45 Gy. Results: The prescribed dose was 50 Gy in each case. The mean percent of volumes that received 45 Gy (V 45) for the RTOG guideline-based contours were CW 74%, Ax1 84%, Ax2 88%, Ax3 96%, SCV 84%, and IM 80%. Mean heart V 10 values were 11% for treatment of left-sided tumors and 6% for right-sided tumors. Mean ipsilateral lung V 20 values were 28% for left-sided tumors and 34% for right-sided tumors. For the contour-based plans, mean V 45 values were CW 94%, Ax1 95%, Ax2 97%, Ax3 98%, SCV 98%, and IM 85%. Mean heart V 10 values were 14% for treatment of left-sided tumors and 12% for right-sided tumors. Mean ipsilateral lung V 20 values were 32% for left-sided tumors and 45% for right-sided tumors. Conclusions: Clinically derived treatment plans, which have proven efficacy and are the current standard, cover 74% to 96% of the anatomy-based RTOG consensus volumes to the prescription dose. This discrepancy should be considered if treatment planning protocol guidelines are designed to incorporate these new definitions.
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U2 - 10.1016/j.prro.2011.10.001
DO - 10.1016/j.prro.2011.10.001
M3 - Article
C2 - 24674124
AN - SCOPUS:84862639582
SN - 1879-8500
VL - 2
SP - 201
EP - 209
JO - Practical radiation oncology
JF - Practical radiation oncology
IS - 3
ER -