Beam angle optimization and reduction for intensity-modulated radiation therapy of non-small-cell.lung cancers
Beam angle optimization and reduction for intensity-modulated radiation therapy of non-small-cell.lung cancers
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DOI：
10.1016/j.ijrobp.2006.01.033
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发表时间：
2006-06-01
影响因子：
7
通讯作者：
Mohan, R
中科院分区：
文献类型：
--
作者：
Liu, HH;Jauregui, M;Mohan, R
目的：优化射束角度，减少非小细胞肺癌调强放射治疗(IMRT)所需的射束数目。方法与材料：采用穷举搜索法对非小细胞肺癌调强放疗的射束角度进行优化。这种方法包括对所有可能的波束角度组合进行相互比较，并根据治疗计划优化中使用的目标函数的分数或成本选择最佳角度。选择10例III期非小细胞肺癌患者，评价BAO算法和IMRT-BAO的剂量学效益。优化了使用5或7个共面射束的调强放射治疗方案，并与使用9个等间距射束的方案进行了比较。结果：每种解剖结构，如肿瘤或肺，都有其各自的首选射束角度。因此，鲍康如需要在相互竞争的目标函数之间取得适当的平衡。使用较少角度(五个或七个波束)的平面图可以获得与使用九个等间距波束的平面图类似的平面图质量，但是减少了监测单元和现场分段。用于治疗的射野数量(5个)和剂量调制(开放或调强放射治疗)对BAO的结果没有显著影响。结论：使用较少的射野(例如5个)进行肺调强放疗可以获得可接受的计划质量，但提高了治疗效率。利用较少的非调制波束，可以开发出一种多分辨搜索方案，以降低该算法的计算量。(C)2006年爱思唯尔公司。
Purpose: To optimize beam angles and reduce the number of beams used for intensity-modulated radiation therapy (IMRT) of non-small-cell lung cancer (NSCLC).Methods and Materials: An exhaustive search scheme was used to perform beam angle optimization (BAO) for IMRT of NSCLC. This approach involved intercomparison of all possible beam angle combinations and selection of the best angles based on the scores or costs of the objective functions used in the treatment plan optimization. Ten Stage III NSCLC cases were selected to evaluate the BAO algorithm and dosimetry benefits of IMRT-BAO. IMRT plans using five or seven coplanar beams were optimized and compared with those using nine equal-spaced beams. Results of BAO were also compared between plans using different numbers of beams with or without fluence modulation.Results: Each anatomic structure, e.g., tumor or lung, had its own preferred beam angles. Thus, BAO required appropriate balance of competing objective functions. Plans using fewer angles (five or seven beams) could achieve plan quality similar to those using nine equal-spaced beams, however with reduced monitor units and field segments. The number of beams used for the treatment (five vs. seven) and the fluence modulation (open or IMRT beams) did not have a significant impact on the results of the BAO.Conclusions: Use of fewer beams (e.g., five) for lung IMRT could result in acceptable plan quality but improved treatment efficiency. A multiresolution search scheme could be developed for BAO using fewer and nonmodulated beams to reduce the computation cost of BAO. (c) 2006 Elsevier Inc.