LUNG DOSE FOR MINIMALLY MOVING THORACIC LESIONS TREATED WITH RESPIRATION GATING
LUNG DOSE FOR MINIMALLY MOVING THORACIC LESIONS TREATED WITH RESPIRATION GATING
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DOI：
10.1016/j.ijrobp.2009.08.021
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发表时间：
2010-05-01
影响因子：
7
通讯作者：
Lerma, Fritz A.
中科院分区：
文献类型：
--
作者：
Mihaylov, Ivaylo B.;Fatyga, Mirek;Lerma, Fritz A.
目的：为了评估偶发剂量良性肺组织的患者与最小移动肺部病变治疗呼吸gating.Methods和材料：17例肺部患者计划进行了回顾性研究。所有病例中肿瘤运动均小于5 mm。对于每例患者，重建了通气中期（MidVen）和吸气中期（MidInh）呼吸阶段。MidInh阶段集中在30%门控窗口内的吸气结束（EOI）阶段。在MidVen阶段描绘计划靶体积、心脏和脊髓，并转移到MidInh阶段。在每个阶段分别绘制肺轮廓。在MidVen阶段生成调强放疗计划。将计划转移至MidInh阶段，并重新计算剂量。评价指标基于目标和关键结构的剂量指数、体积指数、广义等效均匀剂量和质量指数。统计检验被用来建立的参考（MidVen）和比较（MidInh）剂量distribution.Results之间的差异的意义：统计检验表明，评估目标，脊髓和心脏的指数不同的2.3%。然而，在肺部的指数差异超过6%，表明潜在的可实现的肺保护和/或剂量escalation.Conclusions：呼吸门控是一种临床选择与最小移动肺部病变在EOI治疗的患者。门控对于较大的肿瘤将更有益，因为在这些情况下剂量递增将导致肿瘤控制概率的较大增加。(C)2010年爱思唯尔公司
Purpose: To evaluate incidental doses to benign lung tissue for patients with minimally moving lung lesions treated with respiratory gating.Methods and Materials: Seventeen lung patient plans were studied retrospectively. Tumor motion was less than 5 mm in all cases. For each patient, mid-ventilation (MidVen) and mid-inhalation (MidInh) breathing phases were reconstructed. The MidInh phase was centered on the end-of-inhale (EOI) phase within a 30% gating window. Planning target volumes, heart, and spinal cord were delineated on the MidVen phase and transferred to the MidInh phase. Lungs were contoured separately on each phase. Intensity-modulated radiotherapy plans were generated on the MidVen phases. The plans were transferred to the MidInh phase, and doses were recomputed. The evaluation metric was based on dose indices, volume indices, generalized equivalent uniform doses, and mass indices for targets and critical structures. Statistical tests were used to establish the significance of the differences between the reference (MidVen) and compared (MidInh) dose distributions.Results: Statistical tests demonstrated that the indices evaluated for targets, cord, and heart differed by within 2.3%. The index differences in the lungs, however, are in excess of 6%, indicating the potentially achievable lung sparing and/or dose escalation.Conclusions: Respiratory gating is a clinical option for patients with minimally moving lung lesions treated at EOI. Gating will be more beneficial for larger tumors, since dose escalation in those cases will result in a larger increase in the tumor control probability. (C) 2010 Elsevier Inc.