2Deparment of Radiation Oncology, Acıbadem Altunizade Hospital, İstanbul-Türkiye
3Deparment of Radiation Oncology, University of Health Sciences, Van Training and Research Hospital, Van-Türkiye DOI : 10.5505/tjo.2022.3740 OBJECTIVE
It is aimed to compare the hybrid radiotherapy (RT) plans according to three-dimensional field-in-field (FIF), intensity-modulated RT (IMRT), and volumetric-modulated arc therapy (VMAT) techniques in RT applied to the whole breast volume after breast-conserving surgery.
METHODS
Based on the simulation images of 31 consecutive patients who received whole breast RT, a dose of 50 Gy
(25 fractions) was prescribed to the planned treatment volume (PTV) with 6 MV X-rays, five new plans
were created, respectively (FIF, VMAT, IMRT, H-VMAT, and H-IMRT). Homogeneity criteria for PTV,
volume-dose criteria for peripheral critical organs, and MU values of the plans were evaluated separately
for each plan. Subgroup analyses were performed for the left- and right-sided patients.
RESULTS
Both hybrid plans produced a more homogeneous plan at the target volume compared to the other
three techniques (HI; 0.14, 0.14, 0.16, 0.12, and 0.13, p<0.001, respectively). Again, smaller values for
D2% were obtained with both hybrid techniques (53.25, 53.24, 53.8, 52.41, and 52.47 Gy, respectively,
p<0.001). The mean heart dose for the left-sided irradiations was 3.54, 3.40, 4.33, 3.49, and 3.79 Gy for
the five techniques, respectively (p=0.029). Compared with FIF with the other four techniques for the
left-sided irradiations, the LAD D 10% value was significantly reduced (p<0.001).
CONCLUSION
Hybrid plans provide a more homogeneous dose distribution compared to the use of other techniques
alone, while at the same time, it allows reducing the ipsilateral lung and heart doses.