按照美国医学物理学家协会任务组39协议，使用硫酸亚铁剂量测定法，对临床电子束中用平行板电离室测定的吸收剂量进行验证。

Verification of absorbed dose determined with plane-parallel chambers in clinical electron beams following AAPM Task Group 39 protocol using ferrous sulphate dosimetry.

作者信息

Xu Z, Li H, Almond P R, Guan T Y

机构信息

Department of Radiation Oncology, University of Louisville, Brown Cancer Center, Kentucky 40202, USA.

出版信息

Med Phys. 1996 Mar;23(3):377-81. doi: 10.1118/1.597800.

DOI:10.1118/1.597800

PMID:8815380

Abstract

The absorbed dose values determined with the Exradin and PTW-Markus plane-parallel chambers were compared to the values obtained with the ferrous sulphate dosimetry for a number of the Philips SL25 and the Therac 20 electron beams. For the plane-parallel chambers, the cavity-gas calibration factor Ngaspp, was derived by a direct comparison with a calibrated cylindrical chamber using the three different calibration methods as proposed by the newly published AAPM TG 39 protocol. For the ferrous sulphate dosimetry, an epsilon mG value of 352 x 10(-6) m-2 kg-1 Gy-1 was adopted from ICRU Report No. 35. The average ratio of the dose values determined with the plane-parallel chambers and the dose values determined with the Fricke dosimetry system was 1.001 +/- 1.4%. These measurements are consistent with the AAPM TG 39 protocol.

摘要

将使用Exradin和PTW-Markus平行板电离室测定的吸收剂量值，与使用硫酸亚铁剂量计在多个飞利浦SL25和Therac 20电子束下获得的值进行了比较。对于平行板电离室，腔气校准因子Ngaspp是通过使用新发布的AAPM TG 39协议提出的三种不同校准方法，与校准后的圆柱形电离室直接比较得出的。对于硫酸亚铁剂量计，采用了ICRU第35号报告中的εmG值352×10(-6) m-2 kg-1 Gy-1。平行板电离室测定的剂量值与弗里克剂量计系统测定的剂量值的平均比值为1.001±1.4%。这些测量结果与AAPM TG 39协议一致。