Dosimetric measurements for X(?)-knife beams / 中华放射肿瘤学杂志

ABSTRACT

Purpose: There is no appropriate instrument or devices and corresponding technological specification for measurement of output dose and dose disdribution in stereotactic radiothrapy. Small field of the stereotatic radiotherapy can't be measured by normal ionization chamber for its characteristics.A practible instrument and method were developed for dose measurement in stereotactic irradiation.Materials and Methods:A diode detector with 1mm sensitivety volume and a 0.3cc graphite chamber developed by us are used to measure the dose output & dose distribution in warious phantom for the beams used in stereotactic irradiation.Results:The dose outputs and dose ditributions measured by SCD-61 diode developed by us were tested and verified by TLD dosemeter,and the results show tha there is a 5% consistency for the value at the focus point.Conclusion: the diameter of the detector used for measurement must be smaller than the halt size of the radiation beams to be measured. A diode detector with 1mm sensitivity volume is the best choice for the dosimetric measurements for smaller beams used in stereotactic irradiation.