International Journal of Radiation Oncology*Biology*Physics
Oral Scientific SessionImpact of Incidental Cardiac Radiation on Cardiopulmonary Toxicity and Survival for Locally Advanced Non-Small Cell Lung Cancer: Reanalysis of NRG Oncology/RTOG 0617 With Centrally Contoured Cardiac Structures
Section snippets
Purpose/Objective(s)
RTOG 0617 showed high dose RT had a greater risk of death than standard dose. Higher heart dose was associated with worse overall survival (OS) on multivariate analysis. However, the variability in submitted heart contours and no contouring of substructures limited the ability to accurately quantify the role of heart dose and ultimately set meaningful dose constraints.
Materials/Methods
Five thoracic radiation oncologists collectively contoured the cardiac structures for each available case, guided by a common atlas. Anatomic structures defined were pericardium (P), ventricles (V), atria (A), and coronary space (CS). Volumes of each structure and overlap with PTV, distribution of V5, V10, V20, V30, V40, V45, V60, maximum dose (Dmax), and mean dose (MD) were analyzed. Volumes and doses were compared between centrally contoured P and submitted heart contours. Impact of volume
Results
Among 495 analyzable cases, 57 (11.5%) were not available for re-contouring and excluded. Re-contoured P volumes, PTV overlap with P, and dose volumes were larger than submitted heart contours. On univariate analysis all analyzed dose volumes and MD to P were associated with increased risk of death, P < 0.001. Similar relationships were found with V5-60 and MD to A and V and Dmax to the V, P < 0.01. On multivariate analysis, larger PTV volume and Gr3+ esophagitis remained associated with worse
Conclusion
Excessive RT doses to cardiac structures including pericardium MD, V45 to Atria, ventricles, and CS have a detrimental effect on overall survival. Pericardium MD was associated with severe treatment related pneumonitis.
Acknowledgments: This project was supported by grants U10CA21661 (RTOG-Ops-Stat), U10CA180868 (NRG Oncology Operations), U10CA180822 (NRG Oncology SDMC), U10CA37422 (CCOP), CA81647 (ATC), U24CA180803 (IROC), UG1CA189867 (NCORP) from the National Cancer Institute (NCI) and Bristol
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Author Disclosure: E.M. Gore: None. C. Hu: Research Grant; NCI. V. Bar Ad: None. C.G. Robinson: None. M.D. Wheatley: None. J.A. Bogart: None. Y. Garces: None. V.S. Kavadi: None. S. Narayan: None. P. Iyengar: None. J.S. Witt: None. J.W. Welsh: None. C.D. Koprowski: None. J.M. Larner: Review applications; ASTRO. J.D. Bradley: Research Grant; Mevion Medical, ViewRay Inc.