Allehyani S H
Umm al-Qura University, KSA
Title: 3DCRT versus RapidArc treatment for breast cancer: Dosimetric study
Biography
Biography: Allehyani S H
Abstract
The aim of this study is to compare 3DCRT to RapidArc planning systems using LNAC of 6 MV, 15 MV and 18 MV in terms of dosimetric outcomes of iso-dose distribution, dose volume histogram (DVH), PTV and at risk organs in 6 patients with breast cancer. Plans were created for 6 patients with breast cancer who had received radical RapidArc treatment from 2012 to 2014 at KAMC (King Abdullah Medical City). Dosimetric evaluation metrics were used to compare the two plans in terms of mean, maximum and minimum doses to PTV, Homogeneity Index (HI), Conformity Index (CI), Target Coverage Index (TCI) and mean and maximum doses to critical organs and normal tissue. Dose to 95% of the PTV (D95%) was used to quantify PTV coverage. Mean value of the PTV which was 51.38±2.172 in RapidArc compared to 52.21±1.963 in 3DCRT, which means that RapidArc plan achieved lower mean and maximum doses to the PTV. The maximum dose to the PTV in RapidArc was higher compared to 3DCRT with lower maximum dose to the PTV, (p=0.011). These results explain the statistical advantage in PTV coverage metrics in RapidArc modality. PTV dose coverage, as measured by the minimum dose and the dose to 95% of the volume was higher in the RapidArc plan. RapidArc plan also showed a more homogeneous dose distribution in PTV, achieving an HI of 1.262±0.037 compared with 1.271±0.024 in the 3DCRT plan however, RapidArc and 3DCRT achieved similar CI values and improvement in target coverage index (TCI) in which (TCI) in RapidArc was (0.006±0.003) and (0.008±0.006) in 3D-CRT,(P=0.202). Volumetric modulated arc therapy (VMAT) is better than 3DCRT in term of PTV, conformity and homogeneity for breast cancer.