Author(s): Aref A, Thornton D, Youssef E, He T, TekyiMensah S,
Abstract Share this page
Abstract PURPOSE: To evaluate the dosimetric difference between a simple radiation therapy plan utilizing a single contour and a more complex three-dimensional (3D) plan utilizing multiple contours, lung inhomogeneity correction, and dose-based compensators. METHODS AND MATERIALS: This is a study of the radiation therapy (RT) plans of 85 patients with early breast cancer. All patients were considered for breast-conserving management and treated by conventional tangential fields technique. Two plans were generated for each patient. The first RT plan was based on a single contour taken at the central axis and utilized two wedges. The second RT plan was generated by using the 3D planning system to design dose-based compensators after lung inhomogeneity correction had been made. The endpoints of the study were the comparison between the volumes receiving greater than 105\% and greater than 110\% of the reference dose, as well as the magnitude of the treated volume maximum dose. Dosimetric improvement was defined to be of significant value if the volume receiving > 105\% of one plan was reduced by at least 50\% with the absolute difference between the volumes being 5\% or greater. The dosimetric improvements in 49 3D plans (58\%) were considered of significant value. Patients' field separation and breast size did not predict the magnitude of improvement in dosimetry. CONCLUSION: Dose-based compensator plans significantly reduced the volumes receiving > 105\%, >110\%, and volume maximum dose.
This article was published in Int J Radiat Oncol Biol Phys
and referenced in Atherosclerosis: Open Access