Room: AAPM ePoster Library
Purpose: perform a dosimetric study of VMAT, DCAT, and 3D CRT of SBRT plans using Eclipse treatment planning system with Acuros XB algorithm.
Methods: chose a lung cancer patient who was assigned to be treated with SBRT. SBRT immobilization device was used; non-gated CT and 4DCT were performed. Gross tumor volume (GTV) was contoured based on non-gated CT. Internal target volume (ITV) was contoured based on 10 phases of 4DCT and verified on the Maximum Intensity Projections (MIPs). 5 mm margin was added on ITV to generate PTV. The prescription was 5000 cGy in 5 fractions and 100% prescription dose covered 95% of PTV. VMAT/DCAT/3D CRT plans were made in Eclipse V. 15.6 and all plans meet the criteria of NRG-BR001 and RTOG 0813. Acuros-XB_15605 and 0.2 cm of calculation resolution were used. Heterogeneity correction were applied. The PTV volume is 12.28 cc. V90%, Maximum dose, (V105%-PTV)/PTV, R100%, R50%, D2cm, and doses to critical structures were compared.
Results: of PTV coverage, Maximum Dose, R100, R50, D2cm, critical structures’ doses were shown in Table 1. Based on table 1, all VMAT, DCAT, and 3D CRT plans achieved the criteria of NRG-BR001 and RTOG 0813.
Conclusion: addition to VMAT, DCAT and 3D CRT are good alternative techniques for SBRT.
Not Applicable / None Entered.