Abstract
A comparison of the radiation exposure to the left anterior descending artery (LAD) and left ventricle (LV) was performed for twenty-three left breast cancer patients. For each participant, two tangential fields 3D-CRT, two- and seven-field IMRT and two and four partial arcs VMAT plans were created. Dose constraints for CTV, ipsilateral lung and heart were followed. The V(40Gy), V(30Gy), D(av) of LAD and V(23Gy), V(5Gy), D(av) of LV were calculated and extracted from the plans. Parametric and non-parametric tests were applied to compare the parameters derived from the five treatment techniques. All generated plans fulfilled the dose constraints. The D(av) ranges of the LAD and LV from all examined techniques were 11.77-14.73 Gy and 5.37-6.40 Gy, respectively. The V(40Gy) and V(30Gy) ranges of the LAD were 2.90-12.91% and 10.80-18.51%, respectively. The V(23Gy) and V(5Gy) of the LV were 4.29-7.43% and 18.24-30.05%, respectively. The VMAT plans and seven-field IMRT significantly reduced the V(40Gy), V(30Gy) of LAD and V(23Gy) of LV compared with the two-field treatments (p < 0.05). However, 3D-CRT plans provided statistically lower values for V(5Gy) of LV over the other techniques (p < 0.05). The presented results provide a detailed dataset of the radiation burden of two critical cardiac structures from five radiotherapy techniques.