Purpose: The purpose of this study was to compare the absorbed dose distributions within the heart and lad in patients with left-sided breast cancer who underwent radiotherapy using 3D-CRT, IMRT and VMAT techniques.
Methods: The treatment plans of 11 patients with left-sided breast cancer were analyzed. All of the patients were irradiated in our facility with DIBH 3D-CRT. For all patients the plans in the IMRT (sliding window) and VMAT (Rapid Arc - Varian) techniques were prepared. Cumulative dose-volume histograms (DVH) were used to compare the dose distributions between the plans for each patient. Statistical analysis was carried out using the one-way ANOVA with repeated measurements and Tukey's post hoc test.
Results: The use of IMRT and VMAT techniques allowed for a better coverage of the PTV with 95% isodose and a more homogeneous dose distribution compared to the 3D-CRT technique. The use of dynamic technique (IMRT or VMAT) did not provide significant protection for OARs - only the dose absorbed in LAD was slightly lower.
Conclusion: The use of 3D-CRT allows better protection of critical organs compared to other techniques, except for the dose in the lad artery which was the lowest in IMRT technique. exposure of large tissue volumes to so-called low radiation doses is undoubtedly a disadvantage of using dynamic techniques.