摘要：
目的 用热释光剂量计(TLD)和光致发光剂量计(OSLD)测量125I粒籽源植入过程中职业人员眼晶状体和手部皮肤剂量,并进行对比分析.方法 从同批次中,选取TLD退火,包装,贴在仿真人模体腹部平坦处,125I粒籽源放在与模体相同高度,距离15 cm处,分别照射不同剂量:1.0、1.5、3.0、5.0、10.0、12.0、20.0、25.0、30.0、50.0、60.0μGy,照射后的TLD经热释光测量仪测量,建立标准空气比释动能刻度曲线;选择2家医院4个部位:肺部14例、腹部10例、盆腔5例和颈部6例进行125I粒籽源植入治疗,将刻度完的TLD分别贴在职业人员眼部的左、中、右位置,手部左、右位置,进行测量,得到相应部位的空气比释动能值,最后用眼部Hp(3)转换因子和手部Hp(0.07)转换因子分别计算职业人员眼晶状体和手部皮肤剂量当量值.同时建立OSLD测量方法,将退火后的OSLD放在与TLD相同位置直接测量职业人员眼晶状体和手部皮肤剂量当量结果 125I粒籽源植入治疗过程中,应用TLD测量得到手术医生和助手的眼晶状体累积剂量当量分别为0.8和1.6 mSv(肺部)、1.3和1.2 mSv(腹部)、0.9和0.6mSv(盆腔)、均为0.3mSv(颈部);手部累积剂量当量分别为1.4和2.1 mSv(肺部)、1.2和1.0 mSv(腹部)、0.5和0.9 mSv(盆腔)、均为0.1 mSv(颈部);单次手术植入时,职业人员眼晶状体和手部接受的最大剂量当量分别为1.2和1.0 mSv.应用OSLD测量得到肺部治疗时手术医生和助手的眼晶状体累积剂量当量分别为0.2和0.1 mSv,手部累积剂量当量分别为0.4和0.6 mSv;腹部治疗时手术医生手部累积剂量当量为0.1 mSv;其他部位治疗时不同职业人员的剂量当量值均为0 mSv.结论 TLD不仅能给出累积剂量当量,也能给出单次手术的剂量当量,按照ICRP 118号报告修订后规定的职业人员眼晶状体限值,本实验中以单次治疗时眼晶状体接受的最大剂量当量估算,则每年植入病例数不应超过17例.OSLD只能给出累积剂量,测量低剂量的准确性有待研究.%Objective To measure the doses to eye lens and hands of workers,using thermo luminescent dosimeter (TLD) and optically stimulated luminescence dosimeter (OSLD).Methods TLDs in the same batch were annealed,packed and stuck to the flat abdomen of Alderson-Phantom at a distance of about 15 cm from 125I seed source,while irradiated at different doses:1.0,1.5,3.0,5.0,10.0,12.0,20.0,25.0,30.0,50.0 and 60.0 μ Gy.And then TLDs were measured by dosimeters to establish a dose calibration curve.By implanting seed source into the selected lung for 14 cases,belly for 10 cases,pelvic for 5 case and neck for 6 cases while placing calibrated TLDs on the left,middle and right above eyes,left and right hands of the workers to obtain the location-specific kerma values.Finally,the conversion factors Hp (3) and Hp (0.07) were used to calculate the values of dose equivalent to eye lens and hands.Additionally,OSLDs were used to measure the doses to workers in the same way.Results The TLD-measured eye lens dses to the operator and his assistant were 0.8 and 1.6 mSv in lungs,1.3 and 1.2 mSv in bellies,0.9 and 0.6 mSv in pelves,0.3 mSv in necks,respectively.Meanwhile,hand doses to the operator and his assistant were 1.4 and 2.1 mSv in lungs,1.2 and 1.0 mSv in bellies,0.5 and 0.9 mSv in pelves,0.1 mSv in necks,respectively.The maximum doses to eye lens and hands were 1.2 and 1.0 mSv,respectively in a single treatment.OSLD-measured dose equivalents from lung therapy were 0.2 and 0.1 mSv for eye lens of the operator and his assistant and 0.4 and 0.6 mSv for hands.For belly therapy,the accumulated dose equivalent to hands of the operator was 0.1 mSv while those for other types of therapy were 0 mSv.Conclusions TLDs have the capability to measure not only accumulated dose but also dose equivalent from a single therapy According to ICRP 118 publication and as estimated in the present study,the number of therapy should be not more than 17 every year.OSLDs only give the accumulated dose,the accuracy of which needs to be studied in low-dose measurement.
