Commissioning for Treatment Planning System

Objective: A process and system of treatment planning is very important in radiation therapy. The features of the software and the accuracy in the dose calculation and dose distribution will affect to the treatment quality as well as the patient outcome. When a treatment planning system is applied in treatment at the first time, it should be checked and approved all its system information, features, plan assessment tools and dose calculation modules as well. That process is called Commissioning for treatment planning system. Materials and methods: In 2013, Medical and Radiation Oncology department-Cho Ray hospital has utilized Elekta Synergy Platform using XiO vs 4.80 treatment planning system. The commissioning for XiO was performed according to international procedures and protocols which were set up by our Medical Physics. All system information, the features and functions of the software and the beam data were collected as well. To validate and ensure the possibilities in clinical application, some comparisons and assessments between XiO calculations and the actual measurements in water/solid phantom were setup for opened/wedged field size percentage depth doses, beam profiles, algorithms with/without electron density correction, monitor units. Results and Conclusions: The results for percentage depth dose have shown that the maximum accuracy was 0.8% in all treatment depths and less than 1% in the depth of 10cm, with opened-field and wedged-field, respectively. 2.06% of relative dose accuracy in low dose gradients and 0.25mm of spatial accuracy in high dose gradients was estimated. We found the accuracy of 17.55% in nasal cavity and 8.94% in lung case between the algorithms with/without electron density correction. And the maximum accuracy was about 1% in opened-field for monitor unit verification.