Plan optimization and verification in complex treatment delivery techniques such as IMRT and VMAT have been the two major subjects. Because the importance of precise treatment planning and accurate dose delivery is imperative to minimize any possible error in leaf speed, dose rate and gantry rotation. In this work, first the effectiveness of MONACO, which has EUD-based biological optimization combined with physical and radiobiological cost functions and some important parameters in VMAT plan optimization have been studied. Then, dose delivery of different VMAT plans such as Head and Neck (SIB: Simultaneously Integrated Boost), lung (SBRT: Stereotactic Body Radiation Therapy) and prostate (Hypo-fractionated intensity modulated arc therapy) with the Octavius 4D system has been evaluated using gamma index analysis.