儋州市某医院新建核医学科放射防护效果评价

Evaluation of radiation protection effect of new nuclear medicine department in a hospital of Danzhou City

目的 对儋州市某医院新建核医学科进行放射防护评价,了解单光子发射计算机断层成像术-计算机断层成像(single-photon emission computed tomography-computed tomography,SPECT-CT)诊断、甲功测定、甲亢治疗的放射防护水平。方法 2021年8—10月采用现场调查法和检测检验法,对儋州市某医院新建核医学科工作场所进行放射防护检测、表面污染检测、设备性能检测、通风换气检测及放射防护评价。结果 SPECT-CT工作区注射台窗口(开)、分装柜观察窗、分装柜操作口(开)、废物室防护门和留观室防护门、SPECT-CT机房防护门处的剂量率较高。SPECT-CT中的计算机断层扫描(computed tomography,CT)工作场所辐射水平的周围剂量当量率为0.13~0.19μSv/h,处于环境本底水平。核医学科放射工作场所的表面污染检测结果均小于探测下限,即<0.09 Bq/cm^(2)。SPECT-CT中的SPECT和CT的设备性能检测指标均符合相关标准。通风橱截面风速未达到1 m/s,部分放射工作场所通风换气次数<4次/h。结论 建议院方针对关注点剂量率较高的区域,加强放射防护管理,设置警示标识和中文警示说明,医护人员与受检者短暂停留,规定过程完成后不得在以上区域逗留。通风橱更换大功率风机,增大截面风速。在每个功能房间增设气流单向电动阀,避免各房间通风管道气流互通。在通风橱排风口、各功能用房排风口处增设可更换滤芯的活性炭过滤装置,并定期更换活性炭。

Objective To evaluate of radiation protection effect of new nuclear medicine department in a hospital of Danzhou City,understand the radiation protection level of single-photon emission computed tomography(SPECT-CT),thyroid function determination and hyperthyroidism therapy. Methods From August to October 2021,the field investigation and testing method were used to conduct the radiation protection detection,surface pollution detection,equipment performance detection,ventilation detection and radiation protection evaluation in the workplace of new nuclear medicine department in a hospital of Danzhou City. Results The dose rates of injection table window( open), cabinet observation window, operation port( open), waste room protection door,observation room protection door in SPECT-CT work area were high. The peripheral dose equivalent rate of computed tomography(CT) workplace radiation level in SPECT-CT was 0.13-0.19 μSv/h,which was in the environmental base level. The surface contamination detection results in radiation workplace of nuclear medicine department were less than the low limit of detection,that was <0.09 Bq/cm^(2). The equipment performance detection indicators of SPECT and CT in SPECT-CT all met the relevant standards. The wind speed of ventilation cabinet section did not reach 1 m/s,and ventilation in some radioactive workplaces was less than 4 times/h. Conclusions It is suggested that the hospital should strengthen the radiation protection management for the areas with high dose rate,set up warning signs and warning instructions in Chinese,and the medical staff and the interviewees stay briefly,and shall not stay in the above areas after the completion of the prescribed process. It is necessary to use the high-power fan in the ventilation cabinet to increase the cross-section wind speed. The one-way electric valve should be added in functional rooms to avoid ventilation exchange of ventilation pipes between rooms. It is necessary feasible to add the replaceable activated carbon filter device at the exhaust outlet of the ventilation cabinet and functional rooms,and replace the activated carbon regularly.