Electron conformal radiotherapy using bolus and intensity modulation
Electron conformal radiotherapy using bolus and intensity modulation
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DOI：
10.1016/s0360-3016(02)02811-0
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发表时间：
2002-07-15
影响因子：
7
通讯作者：
Antolak, JA
中科院分区：
文献类型：
--
作者：
Kudchadker, RJ;Hogstrom, KR;Antolak, JA
目的：适形电子束治疗可以使用形状丸进行，它改变电子在入射束上的穿透，使90%等剂量表面符合计划靶体积（PTV）的远端表面。先前对这种方式的使用表明，丸的不规则近端表面导致PTV中的剂量不均匀性从10%，即平坦水面的典型剂量扩散增加到约20%。本工作评估了通过改变入射电子强度来恢复剂量均匀性的能力。方法与材料：3例胸壁癌、胸腔癌和头颈癌患者，计划采用电子适形治疗，包括大剂量、强度调节和不强度调节。所得剂量分布和剂量-体积直方图与非调强丸方案进行比较。结果：所有病例的PTV均降低；例如，对于头颈部病例，PTV的DeltaD（90%-10%）从14.9%降低到9.2%。这种剂量扩散的减少是强度调制的直接结果。结论：强度调制电子束可显著改善形状丸电子适形治疗患者PTV的剂量均匀性。(C) 2002爱思唯尔科学有限公司
Purpose: Conformal electron beam therapy can be delivered using shaped bolus, which varies the penetration of the electrons across the incident beam so that the 90% isodose surface conforms to the distal surface of the planning target volume (PTV). Previous use of this modality has shown that the irregular proximal surface of the bolus causes the dose heterogeneity in the PTV to increase from 10%, the typical dose spread of a flat-water surface to approximately 20%. The present work evaluates the ability to restore dose homogeneity by varying the incident electron intensity.Methods and Materials: Three patients, one each with chest wall, thorax, and head-and-neck cancer, were planned using electron conformal therapy with bolus, with and without intensity modulation. Resulting dose distributions and dose-volume histograms were compared with non-intensity-modulated bolus plans.Results: In all cases, the for the PTV was reduced; for example, for the head-and-neck case, the DeltaD(90%-10%) for the PTV was reduced from 14.9% to 9.2%. This reduction in dose spread is a direct result of intensity modulation.Conclusions: The results showed that intensity-modulated electron beams could significantly improve the dose homogeneity in the PTV for patients treated with electron conformal therapy using shaped bolus. (C) 2002 Elsevier Science Inc.