Robert Ngangom, Tripathi Manjul, Trivedi Gaurav, Chauhan R P, Oinam Arun, Singh Ranjit, Tomar Parsee
Department of Radiotherapy, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
J Radiosurg SBRT. 2021;7(3):245-248.
The study was to find the optimal values of priority in the inverse planning module of Leksell GammaPlan which would give better treatment plan indices in GammaKnife SRS. The study showed that the best optimised setting of the weighting or priority in the inverse planning module of Leksell GammaPlan were 0.6 for coverage, 0.3 for gradient index and 0.5 for beam on time. Inverse plans (Hybrid Inverse Plan, HIP) which were made using this optimal priority setting were compared with forward plans (FP) with all 95% coverage. The results showed that the average selectivity index (SI) was 83.05±9.68 for FP and 85.35±8.03 for HIP. So, SI improved in the HIP technique by about 2.3% compare to FP. Similarly, average gradient index (GI) for FP and HIP were respectively 2.82±0.23 and 2.76±0.33. And the average beam on time (BT) of FP and HIP were, respectively, 48.15±23.14 min and 48.35±18.09 min. So, all plan indices show improvement in the hybrid inverse planning technique over forward plans. Consequently, this will improve the quality of patient treatment in GammaKnife.
该研究旨在找出Leksell GammaPlan逆向计划模块中优先级的最佳值，以便在伽玛刀立体定向放射治疗（SRS）中获得更好的治疗计划指标。研究表明，Leksell GammaPlan逆向计划模块中权重或优先级的最佳优化设置为：靶区覆盖率为0.6，梯度指数为0.3，射束开启时间为0.5。将使用此最佳优先级设置生成的逆向计划（混合逆向计划，HIP）与覆盖率均为95%的正向计划（FP）进行比较。结果显示，FP的平均选择性指数（SI）为83.05±9.68，HIP的平均选择性指数为85.35±8.03。因此，与FP相比，HIP技术的SI提高了约2.3%。同样，FP和HIP的平均梯度指数（GI）分别为2.82±0.23和2.76±0.33。FP和HIP的平均射束开启时间（BT）分别为48.15±23.14分钟和48.35±18.09分钟。所以，与正向计划相比，所有计划指标在混合逆向计划技术中均有改善。因此，这将提高伽玛刀治疗患者的质量。
