Valve Assi, Kulmala Antti, Followill David, Tenhunen Mikko
Cancer Center, Department of Radiation Oncology, Helsinki University Hospital, Helsinki, Finland.
IROC, M D Anderson Cancer Center, Houston, TX, USA.
Phys Imaging Radiat Oncol. 2019 May 1;10:25-28. doi: 10.1016/j.phro.2019.04.003. eCollection 2019 Apr.
Uniform dose distribution with steep lateral gradient within depth range of 0-0.5 cm is crucial to be able to treat small skin lesions. The standard nominal 4 MeV electron beam from Elekta Versa HD linear accelerator was modified with degrading filter to remove the lateral scatter from treatment head and minimize the penumbra. The energy degrading method was verified based on dosimetric properties and output factors (OFs) with comparison of four types of measurement methods. The properties of degraded 4 MeV electron beam and developed electron applicators seem optimal for treating small targets near the skin surface.
在0 - 0.5厘米深度范围内具有陡峭横向梯度的均匀剂量分布对于能够治疗小的皮肤病变至关重要。利用降解滤波器对Elekta Versa HD直线加速器的标准标称4兆电子伏电子束进行了修改，以去除治疗头的横向散射并使半影最小化。基于剂量学特性和输出因子（OFs），通过比较四种测量方法对能量降解方法进行了验证。降解后的4兆电子伏电子束的特性以及所开发的电子施源器似乎最适合治疗皮肤表面附近的小目标。
