Zhao L, Das I J, Zhao Q, Thomas A, Adamovics J, Oldman M
Midwest Proton Radiotherapy Institute, Bloomington, IN, USA 47404.
J Phys Conf Ser. 2010;250(1):12035. doi: 10.1088/1742-6596/250/1/012035.
PRESAGE™ dosimeter dosimeter has been proved useful for 3D dosimetry in conventional photon therapy and IMRT [1-5]. Our objective is to examine the use of PRESAGE™ dosimeter for verification of depth dose distribution in proton beam therapy. Three PRESAGE™ samples were irradiated with a 79 MeV un-modulated proton beam. Percent depth dose profile measured from the PRESAGE™ dosimeter is compared with data obtained in a water phantom using a parallel plate Advanced Markus chamber. The Bragg-peak position determined from the PRESAGE™ is within 2 mm compared to measurements in water. PRESAGE™ shows a highly linear response to proton dose. However, PRESAGE™ also reveals an underdosage around the Bragg peak position due to LET effects. Depth scaling factor and quenching correction factor need further investigation. Our initial result shows that PRESAGE™ has promising dosimetric characteristics that could be suitable for proton beam dosimetry.
PRESAGE™剂量仪已被证明在传统光子治疗和调强放射治疗(IMRT)的三维剂量测定中很有用[1-5]。我们的目标是研究PRESAGE™剂量仪在质子束治疗中用于验证深度剂量分布的情况。用79 MeV的未调制质子束照射三个PRESAGE™样品。将从PRESAGE™剂量仪测得的百分深度剂量分布与使用平行板高级马库斯电离室在水模体中获得的数据进行比较。与在水中的测量结果相比,从PRESAGE™确定的布拉格峰位置在2毫米以内。PRESAGE™对质子剂量显示出高度线性响应。然而,由于传能线密度(LET)效应,PRESAGE™在布拉格峰位置附近也显示出剂量不足。深度缩放因子和猝灭校正因子需要进一步研究。我们的初步结果表明,PRESAGE™具有有前景的剂量学特性,可能适用于质子束剂量测定。