^(99m)Tc-甲氧基异丁基异腈心肌灌注显像患者对公众人群及核医学技师照射剂量的估算

Estimation of Radiation Dose from Patients Undergoing ^(99m)Tc-Methoxy Isobutyl Isonitrile Myocardial Perfusion Imaging to the General Public and Nuclear Medicine Technicians

目的估算99m Tc-甲氧基异丁基异腈(MIBI)心肌灌注显像患者对公众人群及核医学技师的照射剂量(RD)。方法前瞻性选取2015年1月-6月行99m Tc-MIBI心肌灌注显像的55例患者,其中男30例,女25例;年龄25~87岁,平均(63.6±15.1)岁。在静脉注射99m Tc-MIBI 1.5 h后,利用辐射监测剂量仪测量患者0.3、1.0 m处的剂量当量率。依据国际辐射防护委员会提出的99m Tc-MIBI人体代谢速率及美国国家辐射防护和测量委员会提出的人类社会活动模式,计算99m Tc-MIBI心肌显像患者完成显像离开核医学科室后,对公众人群的RD。假定核医学技师因摆放体位短期接触99m Tc-MIBI心肌显像患者的时间为5 min,距离为0.3 m,计算技师的RD。结果与99m Tc-MIBI心肌显像患者夜间同床共睡的家庭成员RD为42.88~160.55μSv;白天接触的家庭成员,RD为7.50~29.38μSv;单位工作同事的RD为9.89~38.78μSv;邻座乘客的RD为124.48~466.06μSv。核医学技师每接触1位99m Tc-MIBI心肌显像患者,RD为1.72~6.44μSv。结论 99m Tc-MIBI心肌灌注显像患者对公众及核医学技师的RD远低于相应人群的照射剂量限值。

Objective To estimate the radiation dose（RD） to the general public and nuclear medicine technicians from patients undergoing -（99m）Tc-methoxy isobutyl isonitrile（MIBI） myocardial perfusion imaging.Methods From January to June 2015,55 patients including 30 males and 25 females aged between 25 and 87 years[averaging（63.6±15.1）years]ready to undergo myocardial perfusion scintigraphy with -（99m）Tc-MIBI were prospectively recruited in this study.Approximately at hour 1.5 after injection of -（99m）Tc-MIBI,whole-body dose-equivalent rate was measured with a radiationsurvey meter at 0.3 meter and 1.0 meter from the patients.On the basis of human -（99m）Tc-MIBI metabolic rate proposed by the International Commission of Radiological Protection and human social contact model proposed by the National Council on Radiation Protection and Measurements,the RDs to the general public from patients who had completed-（99m）Tc-MIBI myocardial perfusion imaging and left nuclear medicine department were calculated.On the assumption that a nuclear medicine technician typically spent 5 minutes at a distance of 0.3 meter for positioning the patient,the technician＇s RD was also estimated.Results The RD to a family member sleeping with the patient at night was predicted to be 42.88-160.55 μSv,to a family member contacting the patient at daytime 7.50-29.38 μSv,to a colleague9.89-38.78 μSv and to a nearby passenger 124.48-466.06 μSv.The RD to a technician per -（99m）Tc-MIBI myocardial perfusion imaging procedure was predicted to be 1.72-6.44 μSv.Conclusion The predicted RDs to the general public and technicians from exposure of patients undergoing -（99m）Tc-MIBI myocardial perfusion imaging are significantly lower than the regulatory dose limits.