Author(s)

Phillip Prior¹, Irina Sparks¹, J. Frank Wilson¹, Joseph Bovi¹, Adam Currey^1*, Julie Bradley¹, Tracy Kelly¹, X. Allen Li¹, Julia R White²

¹Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA.
²Department of Radiation Oncology, Ohio State University, Columbus, OH, USA.

Purpose: This work evaluates the use of target and organs at risk (OAR) dose-volume goals in 3D conformal radiotherapy (3DCRT) planning for node positive breast cancer (NPBC) patients undergoing regional nodal irradiation after lumpectomy/mastectomy. Methods: Dosimetric data for 262 NPBC patients receiving regional nodal and whole breast/chest wall (WB/CW) irradiation from 2000-2009 were analyzed. In all cases, target & OAR volumes were delineated on treatment CT scans for field generation and dose-volume histograms (DVHs) were generated. Cases were analyzed to identify how frequently they met treatment planning institutional dose-volume goals (“institutional guidelines” & standardized in 2005) and how this would affect OAR doses. Results: The incidence of cases from 2000-2009 meeting current institutional guidelines improved over the study period. Target coverage improved from 2005-2009, when guidelines were followed as a part of the plan approval. Those cases from 2000-2004 meeting acceptable target goals were found to be significantly different from those cases from 2005-2009 (p < 0.01). However, no significant difference between cases meeting OAR goals for plans from 2000-2004 versus 2005-2009 was found. Conclusions: The use of institutional guidelines in 3DCRT for WB/CW and regional nodal irradiation for NPBC patients improved target coverage without a statistically significant increase in heart and lung doses.

Node Positive Breast Cancer, Dose-Volume Goals, Target Coverage, CT Based Planning

Prior, P. , Sparks, I. , Wilson, J. , Bovi, J. , Currey, A. , Bradley, J. , Kelly, T. , Li, X. and White, J. (2017) Use of Three Dimensional Conformal Radiation Therapy for Node Positive Breast Cancer Does Not Result in Excess Lung and Heart Irradiation. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 6, 1-9. doi: 10.4236/ijmpcero.2017.61001.