Department of Radiation Oncology, Adana Research and Treatment Centre, Baskent University Faculty of Medicine, 01120 Adana, Turkey.
Jpn J Radiol. 2012 Apr;30(3):218-26. doi: 10.1007/s11604-011-0034-7. Epub 2011 Dec 21.
To analyze tangential wedged beam and field-in-field (FIF) technique doses using dose-volume histograms and conformality indices for target volume and healthy tissues within the irradiated volume.
Thirty patients treated with breast-conserving surgery and postoperative whole breast radiotherapy were enrolled. Three plans were generated: a standard tangential plan with either one outer field wedge or bilateral wedges, and an FIF plan. Three indices were used: the dose homogeneity index (DHI), PTV dose improvement index (PDI(index)) and geometric conformity index (g). Also ipsilateral lung, heart and contralateral breast doses were compared for each plan.
Dose homogeneity index was significantly lower for the FIF (0.117 ± 0.021) than for the single wedge (0.131 ± 0.025, p = 0.02) and double wedged plan (0.128 ± 0.025, p = 0.04), respectively. The g was significantly less in the FIF (0.70 ± 0.14) compared to the wedge plans (0.80 ± 0.17, p = 0.02 and 0.83 ± 0.16, p = 0.003). Contralateral breast doses were significantly lower in the FIF plan. The FIF plan significantly lowered MU compared to both the single wedge and bilateral wedge plans.
The dose distribution within the target was more homogenous, and the doses for healthy tissue were less in the FIF plan compared to the tangential wedge plans.
通过剂量体积直方图和适形性指数分析切线楔形射束和适形调强放疗（FIF）技术的剂量，以评估靶区和照射野内健康组织的剂量。
共纳入 30 例接受保乳手术和术后全乳放疗的患者。生成了 3 种计划：一种是标准的切线野，采用单侧或双侧楔形野，另一种是 FIF 计划。使用了 3 个指数：剂量均匀性指数（DHI）、PTV 剂量改善指数（PDI(index)）和几何适形指数（g）。还比较了每个计划中同侧肺、心脏和对侧乳腺的剂量。
FIF 计划的剂量均匀性指数（0.117 ± 0.021）明显低于单侧楔形野（0.131 ± 0.025，p = 0.02）和双侧楔形野计划（0.128 ± 0.025，p = 0.04）。FIF 计划的 g 显著小于楔形野计划（0.70 ± 0.14 与 0.80 ± 0.17，p = 0.02 和 0.83 ± 0.16，p = 0.003）。FIF 计划的对侧乳腺剂量明显较低。与单侧楔形野和双侧楔形野计划相比，FIF 计划的 MU 明显降低。
与切线楔形野计划相比，FIF 计划的靶区剂量分布更均匀，健康组织的剂量更低。
