Room: ePoster Forums
Purpose: It is very important to optimize the parameters in the planning of inverse intensity modulated radiotherapy (IMRT) for breast cancer. The purpose of this study is to obtain the relationship between the organs in danger and the target area by using the program analysis and evaluation software,and further to obtain the reasonable parameters of inverse optimization in the design of the plan.
Methods: Twenty patients with left breast cancer were selected. The location information between OARS and PTV was obtained by PLAN IQ program analysis software and the dose was predicted.OARS includes left lung,right lung,heart,spinal cord and healthy breast. PTV included the target volume of the left chest wall (14 cases after total mastectomy and 6 cases after conserving breast). The software can automatically predict the impossible target parameters to make use of the optimization process of the intensity modulation plan. IMRT technique was used in 10 cases and VMAT technique in 10 cases. Using software to obtain optimal parameters to optimize the treatment plan and artificially set the optimal parameters of the treatment plan for dose comparison.
Results: The average organ acceptance of the optimal treatment plan was lower than that of the artificial plan,especially in the protection of the heart and the affected lung. The Vâ‚‚â‚€ of the affected lung decreased by 2.5% on average,and the Vâ‚… of the heart decreased by 2.2% on average. The target dose of artificial planning is more prominent,but the two kinds of planning target dose can meet the clinical dose requirements.
Conclusion: It is feasible to obtain the optimized parameters according to the location relationship between OARS and PTV by using the software. It can make the inexperienced physicists find the optimized parameters more conveniently and the planning quality is higher.