-
99Tcm-MDP骨显像是临床核医学最常见的诊疗项目之一[1],我国核医学现状的普查结果显示,2017年99Tcm-MDP骨显像达128.5万例次[2]。近些年,随着99Tcm-MDP骨显像诊疗数量的逐步增加,99Tcm-MDP骨显像患者对公众及医护人员存在潜在照射风险的问题愈发受到关注[3-5]。本研究估算了99Tcm-MDP骨显像患者对公众及核医学技师的照射剂量(radiation dose,RD),以期评估公众及医护人员实际辐射风险的高低。
-
选取2019年9至12月于四川大学华西医院核医学科行99Tcm-MDP骨显像的64例恶性肿瘤患者进行回顾性研究,其中男性38例、女性26例,年龄24~82(55.1±12.8)岁。包括乳腺癌24例、肺癌18例、前列腺癌13例、其他恶性肿瘤9例。所有患者均在检查前签署了知情同意书。本研究符合《赫尔辛基宣言》的原则。
-
99Tcm-MDP由成都欣科医药有限公司提供(放射化学纯度>95%)。显像仪为荷兰飞利浦公司生产的Skylight双探头SPECT仪。辐射剂量的监测使用美国Inspector公司的手持式核辐射监测探测仪(IA-V2型),使用盖革-弥勒计数管,有效直径为45 mm,云母窗密度为1.5 mg/cm3。剂量测量范围为0.01~1100 μSv/h,测量灵敏度为350 cpm/(μSv·h)(cpm为每分钟计数),测量精确度为±10%。
-
患者静脉注射 99Tcm-MDP 740~925 MBq 3 h后,行全身前、后位骨显像,扫描速度为15 cm/min,参数:能峰140 keV、能窗20%、矩阵1024×256、放大倍数1.0。
-
将手持式核辐射监测探测仪置于距地面1 m高的铅柜并保持固定,先测量本底剂量当量率(dose-equivalent rate,DR)。嘱患者于静脉注射99Tcm-MDP 后15 min 分别直立于探测仪前的1.0 m和0.3 m处[6-8]进行DR的测量。每次测量时间为60 s,重复测量3次,取平均值。每次测量时,患者身体的冠状面与探测仪的探测窗保持平行。分别用距患者1.0 m和0.3 m处的DR减去本底DR,得到距患者1.0 m和0.3 m处的DR,记作DR(1.0 m)和DR(0.3 m)。
-
按照美国国家辐射防护和测量委员会(NCRP)155号出版物[9]提出的公众人群RD的计算方法,根据公式(1)计算99Tcm-MDP 骨显像患者对公众的RD,以下公式均参考文献[9]。
$ {\rm{RD}} = 1.44 \times {\rm{DR}} \times {\rm{OF}} \times \int_{{t_1}}^{{t_2}} {\sum\nolimits_{i = 1}^n {{F_i}} } {T_{{e_i}}}{e^{ - \frac{{0.693t}}{{{T_{{e_i}}}}}dt}} $ 公式(1)中,OF为暴露因子(occupancy factor,OF),指接受核素治疗或显像的患者平均每天在特定的距离接触公众人群的时间分数。美国国家辐射防护和测量委员会定义了人类社会活动模式及其对应的OF:①与家庭成员白天接触时,接触距离为1.0 m,接触时间为6 h/d,OF(1.0 m)= 6 h/24 h = 0.25;②与家庭成员夜间同床共寝时,接触距离为0.3 m,睡眠时间为8 h/d,OF(0.3 m)=8 h/24 h=0.33;③与单位同事间接触时,接触距离为1.0 m,接触时间为8 h/d,OF(1.0 m)=8 h/24 h=0.33[9]。t为静脉注射99Tcm-MDP后的时间(h),t1和t2分别为99Tcm-MDP骨显像患者与公众接触的开始和结束时间(h)。国际辐射防护委员会(International Commission on Radiological Protection,ICRP)的128号出版物[10]以房-室模型的形式定义了99Tcm-MDP 在人体内的代谢。Fi为99Tcm-MDP在各室的分布数,分别为0.3、0.3、0.4,
${T_{{e_i}}}$ 为各室的有效半衰期,分别为0.46、1.94、5.56 h。本研究假设患者静脉注射99Tcm-MDP后3 h开始显像,核医学技师因指导体位摆放短暂接触患者,接触时间为5 min,接触距离为0.3 m,即t1=3 h,t2=3.08 h,根据公式(2)计算核医学技师接触1例99Tcm-MDP骨显像患者的RD:
$ {\rm{RD}} = 1.44 \times {\rm{DR}}(0.3\;{\rm{m}}) \times \int_{3.0\;{\rm{h}}}^{3.08\;{\rm{h}}} {\sum\nolimits_{i = 1}^n {{F_i}} } {T_{{e_i}}}{e^{ - \frac{{0.693t}}{{{T_{{e_i}}}}}dt}} $ 假设99Tcm-MDP注射后3.5 h患者完成显像,离开核医学科室,开始接触工作同事和家庭成员,即t1=3.5 h,t2=∞,将不同的OF(即0.25、0.33)代入公式(3)分别计算家庭成员和工作同事的RD:
$ {\rm{RD}} = 1.44 \times {\rm{DR}} \times {\rm{OF}} \times \int_{3.5\;{\rm{h}}}^\infty {\sum\nolimits_{i = 1}^n {{F_i}} } {T_{{e_i}}}{e^{ - \frac{{0.693t}}{{{T_{{e_i}}}}}dt}} $ 患者完成显像当天若全程乘坐公共交通工具,即t1=3.5 h,t2=24 h,OF=1,并假定患者与邻座乘客的距离为0.3 m,根据公式(4)计算邻座乘客的RD:
$ {\rm{RD}} = 1.44 \times {\rm{DR}}(0.3\;{\rm{m}}) \times \int_{3.5\;{\rm{h}}}^{24\;{\rm{h}}} {\sum\nolimits_{i = 1}^n {{F_i}} } {T_{{e_i}}}{e^{ - \frac{{0.693t}}{{{T_{{e_i}}}}}dt}} $ 符合正态分布的RD以
$\bar x $ ±s表示。 -
静脉注射99Tcm-MDP 后15 min,64例患者的DR(1.0 m)为15.9~32.7(22.6±3.6) μSv/h、DR(0.3 m)为70.8~154.2(105.5±20.9) μSv/h。
-
99Tcm-MDP骨显像患者与公众及核医学技师接触产生的RD见表1。
接触人群 照射剂量( ±s)$\bar x $ 照射剂量的范围 家庭成员 夜间同床共睡 116.5±23.4 78.2~170.3 白天接触 18.9±3.0 13.3~27.4 夜间同床共睡+白天接触 135.4±26.0 92.5~195.7 工作同事 25.0±4.0 17.6~36.2 邻座乘客 327.5±65.7 219.9~478. 8 核医学技师(接触1例患者) 5.8±1.2 3.9~8.5 注:MDP为亚甲基二膦酸盐 表 1 99Tcm-MDP骨显像患者对公众及核医学技师产生的照 射剂量(μSv)
Table 1. Radiation dose to the general public and nuclear medicine technicians from contacting patient undergoing 99Tcm-MDP bone scintigraphy (μSv)
99Tcm-MDP骨显像患者对公众及核医学技师照射剂量的估算
Estimated radiation dose from patients undergoing 99Tcm-MDP bone scintigraphy: implications for the general public and nuclear medicine technicians
-
摘要:
目的 估算99Tcm-亚甲基二膦酸盐(MDP)骨显像患者对公众及核医学技师产生的照射剂量。 方法 选取2019年9至12月于四川大学华西医院行99Tcm-MDP骨显像的64例患者进行回顾性研究,其中男性38例、女性26例,年龄24~82(55.1±12.8)岁。在静脉注射99Tcm-MDP 15 min后,使用核辐射监测探测仪测量距离患者1.0 m和0.3 m处的剂量当量率(DR)。根据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和国际辐射防护委员会提出的99Tcm-MDP在人体的代谢模型,计算99Tcm-MDP骨显像患者对公众及核医学技师的照射剂量。 结果 64例患者的DR(1.0 m)为15.9~32.7(22.6±3.6) μSv/h、DR(0.3 m)为70.8~154.2(105.5±20.9) μSv/h。与99Tcm-MDP骨显像患者白天接触的家庭成员的照射剂量为13.3~27.4(18.9±3.0) μSv;夜间同床共寝的家庭成员的照射剂量为78.2~170.3(116.5±23.4) μSv;单位工作同事的照射剂量为17.6~36.2(25.0±4.0) μSv;邻座乘客的照射剂量为219.9~478. 8(327.5±65.7) μSv。核医学技师每接触1例99Tcm-MDP骨显像患者的照射剂量为3.9~8.5(5.8±1.2) μSv。 结论 99Tcm-MDP骨显像患者对公众及核医学技师的照射剂量远低于相应人群的照射剂量限值。 Abstract:Objective Radiation doses to the general public and nuclear medicine technicians from patients undergoing 99Tcm-methylenediphosphonate(MDP) bone scintigraphy were estimated. Methods A total of 64 patients (38 males and 26 females, aged 24–82 (55.1±12.8) years) undergoing bone scintigraphy with 99Tcm-MDP were retrospectively enrolled in this study. Approximately at 15 minutes after injection of 99Tcm-MDP, whole-body dose-equivalent rate (DR) was measured with a radiation-survey meter at 0.3 meter and 1.0 meter from the patients with nuclear radiation monitoring detector. On the basis of the human social contact model defined by the National Council on Radiation Protection and Measurements and human 99Tcm-MDP metabolic rate suggested by the International Commission of Radiological Protection, the radiation doses to the general public and the nuclear medicine technicians after exposure to patients undergoing 99Tcm-MDP bone scintigraphy were calculated. Results The whole-body DR values of 64 patients at 15 minutes after injection of 99Tcm-MDP were 70.8–154.2 (105.5 ± 20.9) and 15.9–32.7 (22.6±3.6) μSv/h, respectively, at 0.3 meter and 1.0 meter. The following radiation doses were estimated: to a family member contacting with a patient at daytime 13.3–27.4 (18.9±3.0) μSv; to a family member sleeping with a patient at night 78.2–170.3 (116.5±23.4) μSv, to a colleague 17.6–36.2 (25.0±4.0) μSv and to a adjacent passenger 219.9–478.8 (327.5±65.7) μSv. The radiation dose to a technician per 99Tcm-MDP imaging patient was estimated to be 3.9–8.5 (5.8±1.2) μSv. Conclusion The predicted radiation doses to the general public and technicians from exposure to patients undergoing 99Tcm-MDP bone scintigraphy are significantly lower than the regulatory dose limits. -
表 1 99Tcm-MDP骨显像患者对公众及核医学技师产生的照 射剂量(μSv)
Table 1. Radiation dose to the general public and nuclear medicine technicians from contacting patient undergoing 99Tcm-MDP bone scintigraphy (μSv)
接触人群 照射剂量( ±s)$\bar x $ 照射剂量的范围 家庭成员 夜间同床共睡 116.5±23.4 78.2~170.3 白天接触 18.9±3.0 13.3~27.4 夜间同床共睡+白天接触 135.4±26.0 92.5~195.7 工作同事 25.0±4.0 17.6~36.2 邻座乘客 327.5±65.7 219.9~478. 8 核医学技师(接触1例患者) 5.8±1.2 3.9~8.5 注:MDP为亚甲基二膦酸盐 -
[1] Zhao Z, Zhou K, Liu B. Added value of SPECT/CT in the evaluation of sacral fracture in patients with lung cancer[J]. Clin Nucl Med, 2018, 43(6): e195−e197. DOI: 10.1097/RLU.0000000000002082. [2] 中华医学会核医学分会. 2018年全国核医学现状普查结果简报[J]. 中华核医学与分子影像杂志, 2018, 38(12): 813−814. DOI: 10.3760/cma.j.issn.2095-2848.2018.12.010.
Chinese Society of Nuclear Medicine. A brief report on the results of the national survey of nuclear medicine in 2018[J]. Chin J Nucl Med Mol Imaging, 2018, 38(12): 813−814. DOI: 10.3760/cma.j.issn.2095-2848.2018.12.010.[3] Hauptmann M, Daniels RD, Cardis E, et al. Epidemiological studies of low-dose ionizing radiation and cancer: summary bias assessment and meta-analysis[J]. J Natl Cancer Inst Monogr, 2020, 2020(56): 188−200. DOI: 10.1093/jncimonographs/lgaa010. [4] Little MP, Kitahara CM, Cahoon EK, et al. Occupational radiation exposure and risk of cataract incidence in a cohort of US radiologic technologists[J]. Eur J Epidemiol, 2018, 33(12): 1179−1191. DOI: 10.1007/s10654-018-0435-3. [5] Bernier MO, Journy N, Villoing D, et al. Cataract risk in a cohort of U. S. radiologic technologists performing nuclear medicine procedures[J]. Radiology, 2018, 286(2): 592−601. DOI: 10.1148/radiol.2017170683. [6] Jin P, Feng HJ, Ouyang W, et al. Radiation dose rates of differentiated thyroid cancer patients after 131I therapy[J]. Radiat Environ Biophys, 2018, 57(2): 169−177. DOI: 10.1007/s00411-018-0736-7. [7] Han S, Jin S, Yoo SH, et al. A practical individualized radiation precaution based on the dose rate at release time after inpatient 131I ablation therapy[J/OL]. PLoS One, 2021, 16(5): e0251627[2020-09-13]. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0251627. DOI: 10.1371/journal.pone.0251627. [8] Stachura A, Gryn T, Kałuża B, et al. Predictors of euthyreosis in hyperthyroid patients treated with radioiodine 131I: a retrospective study[J/OL]. BMC Endocr Disord, 2020, 20(1): 77[2020-09-13]. https://bmcendocrdisord.biomedcentral.com/articles/10.1186/s12902-020-00551-2. DOI: 10.1186/s12902-020-00551-2. [9] National Council on Radiation Protection and Measurements. NCRP report No. 155-management of radionuclide therapy patients(2006)[R]. Bethesda: National Council on Radiation Protection and Measurements, 2006. [10] Mattsson S, Johansson L, Leide Svegborn S, et al. Radiation dose to patients from radiopharmaceuticals: a compendium of current information related to frequently used substances[J]. Ann ICRP, 2015, 44(S2): S7−321. DOI: 10.1177/0146645314558019. [11] López PO, Dauer LT, Loose R, et al. ICRP publication 139: occupational radiological protection in interventional procedures[J]. Ann ICRP, 2018, 47(2): 1−118. DOI: 10.1177/0146645317750356. [12] Foreman C, Dewji S. Estimation of external dose rates to hotel workers from bed linens contaminated by 131I patients[J]. Health Phys, 2020, 118(6): 615−622. DOI: 10.1097/HP.0000000000001141. [13] Stabin MG, Siegel JA. RADAR dose estimate report: a compendium of radiopharmaceutical dose estimates based on OLINDA/EXM version 2.0[J]. J Nucl Med, 2018, 59(1): 154−160. DOI: 10.2967/jnumed.117.196261.