Dosimetric comparison of TomoDirect and TomoHelical plans in post-mastectomy chest wall radiation therapy

The purpose of this study was to evaluate the characteriscs of TomoDirect (TD) plans compared to convenonal TomoHelical (TH) plans in chest wall irradiaon in paents with breast cancer.
TD and TH plans for only chest wall were retrospecvely created for 30 paents previously treated with TH technique in our clinic. The beam angles were arranged to cover PTV chest wall and to minimize doses to OARs, ipsilateral lung and contralateral breast in TD plan. The prescribed dose was 50 Gy in 25 fracons.
The mean treatment mes were similar in TH and TD (310.8 and 309 s, respecvely, p> 0.05). There was no difference between the values of CI and HI of both plans (p>0.05). The values of Dmean, V5 and V20 of the ipsilateral lung in TD plan was significantly lower than that in TH plan for all 30 paents (p0.05).
Both of TH and TD plans produce acceptable target dose coverage in chest wall RT. Considering the risk of low-dose radiaon to the crical organs; TD mode improve dose distribuon.