Keywords:
Breast, Oncology, CT, Intensity Modulated Radiotherapy (IMRT), Radiation therapy / Oncology, VMAT and Tomotherapy, Radiotherapy techniques
Authors:
J. Yeh1, M. Cokelek2, M. Tacey1, E. Holt2, H. Ho2, T. Tran2, B. Subramanian2, F. Foroudi1, M. Chao2; 1Melbourne, VIC/AU, 2Ringwood, VIC/AU
DOI:
10.26044/ranzcr2021/R-0415
Results
When comparing VMAT with t-IMRT techniques, there was no statistically significant difference in the planning target volume receiving 50.40Gy (PTV5040) D95 or D2 coverage (p=0.122, p=0.816, respectively). Within t-IMRT plans, excluding IMN leads to higher D95 coverage (p=0.002).
The heart mean dose and V25 were significantly lower with VMAT than t-IMRT (p<0.001). There was no significant difference to the heart dose whether IMN was included or not. The ipsilateral lung V20 was significantly lower with VMAT than t-IMRT (p<0.001), but not the V5 (p=0.246). Within t-IMRT plans, excluding IMN leads to lower ipsilateral lung V20 (p<0.001).
The t-IMRT plans had lower contralateral lung V5 (p<0.001), and even lower when IMN was not included (p=0.001). The VMAT plans had lower minimum doses to the ipsilateral ribs and intercostal muscles (p<0.001), while the maximum dose was not significantly different (p=0.837)
There was no significant difference to the dose to ipsilateral ribs and intercostal muscles whether IMN was included or not. The contralateral breast mean dose was not significantly different between VMAT and t-IMRT (p=0.073). Within t-IMRT plans, the right breast mean dose was lower if IMN was excluded (p=0.002).