Abstract：Objective To establish a dosimetric method based on the well-chamber to verify the accuracy of the source positioning and dwelling time for the afterloading machine, aiming to provide a new method for the quality control of afterloading machine. Methods The principle of this method was explained according to the hardware structure of the well-chamber. Then, the precision of this method was analyzed by the simulation test and data fitting. The feasibility test was also performed. And the advantages and disadvantages of this method were compared with those of the traditional method. Results The precision of this method for detecting the source positioning was 0.07mm and the dwelling time was 0.09s, respectively. In the feasibility test, the standard deviation of the measure value was below 3%. Conclusions The well-chamber method has high precision and convenient operation. It can be applied in the rapid verification of the relative accuracy of the source positioning and dwelling time of well-chamber.
Zhao Qiang,Wu Xiangyang,Chang Xiaobin et al. Study of the verification of the source positioning and dwelling time based on the well-chamber[J]. Chinese Journal of Radiation Oncology, 2021, 30(3): 278-282.
[1] Karlsson J,Dreifaldt AC,Mordhorst LB,et al.Differences in outcome for cervical cancer patients treated with or without brachytherapy[J].Brachytherapy,2017,16(1):133-140.DOI:10.1016/j.brachy.2016.09.011. [2] DeWerd LA.Quality assurance tool for high dose rate brachytherapy[J].Med Phys,1995,22(4):435.DOI:10.1118/1.597469. [3] 中华人民共和国卫生行业标准.WS 262-2017.后装γ源近距离治疗质量控制检测规[S].北京:中国标准出版社,2007. [4] 于浪,杨波,刘峡,等.后装治疗机放射源驻留位置及计时器精度的质量控制检测[J].中华放射肿瘤学杂志,2018,27(6):598-600.DOI:10.3760/cma.j.issn.1004-4221.2018.06.013. [5] Veltchev I,Price R,Anderson P,et al.SU-F-T-07:Dosimetric impact of the dwell position inaccuracy in HDR ring and tandem treatments with Varisource IX afterloader[J].Med Phys,2016,43(6):3462-3463.DOI:10.1118/1.4956141. [6] Tanderup K,Hellebust TP,Lang S,et al.Consequences of random and systematic reconstruction uncertainties in 3d image based brachytherapy in cervical cancer.[J].Radiother Oncol,2008,89(2):156-163.DOI:10.1016/j.radonc.2008.06.010. [7] Madebo M,Pillainayagam J,Kron T,et al.SU-GG-T-54:A phantom for physics QA to check the accuracy of an Ir-192step0ing source dwell position and reproducibility of dwell time in HDR brachytherapy[J].Med Phys,2010,37(6Part16):3196.DOI:10.1118/1.3468440. [8] Jursinic,P.Quality assurance measurements for high-dose-rate brachytherapy without film[J].J Appl Clin Med Phys,2014,15(1):246-261.DOI:10.1120/jacmp.v15i1.4586. [9] Madebo M,Pillainayagam J,Kron T,et al.A phantom for verification of dwell position and time of a high dose rate brachytherapy source[J].Australas Phys Eng Sci Med,2012,35(3):335-339.DOI:10.1007/s13246-012-0138-0. [10] Hirose A,Ueda Y,Oohira S,et al.A Quality assurance system with a web camera for high dose rate brachytherapy[J].Nihon HoshasenGijutsu Gakkai Zasshi,2016,72(3):227-233.DOI:10.6009/jjrt.2016_JSRT_72.3.227.
2021, Vol. 30 
