The comparison of Co-60 and 4MV photons matching dosimetry during half-beam technique
- 作者：Cakir ; Aydin ; Bilge ; Hatice ; Dadasbilge ; Alpar ; Kü ; cü ; cü ; k ; Halil ; Okutan ; Murat ; et. al.
- 关键词：Caniospinal irradiation ; Half-beam block technique ; Matching dosimetry
- 刊名：Radiation Measurements
- 出版年：2005
- 期刊代码：71_13504487
- 类别：ce
- 出版时间：August, 2005
- 卷：39
- 期：4
- 页码：447-450
- 文件大小：191 K
摘要
In this phantom study, we tried to compare matching dosimetry differences between half-blocking of Co-60 and asymmetric collimation of the 4MV photons during craniospinal irradiation. The dose distributions are compared and discussed. Firstly, some gaps with different sizes are left between cranial and spinal field borders. Secondly, the fields are overlapped in the same sizes. We irradiate the films located in water-equivalent solid phantoms with Co-60 and 4MV photon beams. This study indicates that the field placement errors in Formula Not Shown 1mm are acceptable for both Co-60 and 4MV photon energies during craniospinal irradiation with half-beam block technique. Within these limits the dose variations are specified in Formula Not Shown 5%. However, the setup errors that are more than 1mm are unacceptable for both asymmetric collimation of 4MV photon and half-blocking of Co-60.