Dosimetric verification of helical tomotherapy for total scalp irradiation
Dosimetric verification of helical tomotherapy for total scalp irradiation
复制标题
DOI：
10.1118/1.2996288
复制
发表时间：
2008-11-01
期刊：
影响因子：
3.8
通讯作者：
Tome, Wolfgang A.
中科院分区：
文献类型：
--
作者：
Hardcastle, Nicholas;Soisson, Emilie;Tome, Wolfgang A.
全头皮照射是一种用于各种浅表恶性肿瘤的治疗技术。螺旋断层放射治疗是一种有效的技术用于全头皮照射。最近发表的工作表明，断层治疗计划系统高估了表面剂量。在这项研究中，表面剂量的螺旋断层治疗全头皮照射已被测量的拟人化的幻影，使用放射性变色和射线照相胶片，以及一种新的皮肤剂量计，MOSkin。发现断层治疗计划系统可准确计算表面剂量。这与最近的报告相反，可能是由于计划中使用的较小剂量网格分辨率和主要由与头皮相切的细光束组成的特定治疗的组合。在PTV的选定区域中，在体模的前2 mm深度上，发现表面剂量从33.6增加到41.2戈伊和36.0增加到42.0戈伊，用辐射变色胶片测量。处方剂量为40戈伊。由于热塑性头罩和用于辅助治疗设置的头枕的推注效应，在某些区域，表面剂量等于或高于处方剂量。建议在地表达到处方剂量（
Total scalp irradiation is a treatment technique used for a variety of superficial malignancies. Helical tomotherapy is an effective technique used for total scalp irradiation. Recent published work has shown the TomoTherapy planning system to overestimate the superficial dose. In this study, the superficial doses for a helical tomotherapy total scalp irradiation have been measured on an anthropomorphic phantom using radiochromic and radiographic film as well as a new skin dosimeter, the MOSkin. The superficial dose was found to be accurately calculated by the TomoTherapy planning system. This is in contrast to recent reports, probably due to a combination of the smaller dose grid resolution used in planning and this particular treatment primarily consisting of beamlets tangential to the scalp. The superficial dose was found to increase from 33.6 to 41.2 Gy and 36.0 to 42.0 Gy over the first 2 mm depth in the phantom in selected regions of the PTV, measured with radiochromic film. The prescription dose was 40 Gy. The superficial dose was at the prescription dose or higher in some regions due to the bolus effect of the thermoplastic head mask and the head rest used to aid treatment setup. It is suggested that to achieve the prescription dose at the surface (