碘治疗工作人员甲状腺131I活度的测量与评价

目的 了解核医学科碘治疗工作人员甲状腺内¹³¹I的活度,并估算年待积有效剂量,分析碘治疗人员的内照射现状。方法 选择甲状腺内照射碘测量仪,对山东省6家医院进行调查并进行甲状腺¹³¹I活度测量,得出6家医院核医学科碘治疗工作人员甲状腺¹³¹I的检出率和活度值,进而计算摄入量和年待积有效剂量。结果 6家医院共有63名碘治疗工作人员接受测量,其中有52人甲状腺内检测到¹³¹I,检出率83%,测得¹³¹I活度大多低于200 Bq。估算的年待积有效剂量范围为0.23~7.78 mSv,其中有84.6％的人年待积有效剂量＜2 mSv。结论 核医学科碘治疗工作人员应进行常规内照射个人监测,各医院在辐射防护制度方面需进一步完善。     

碘治疗工作场所空气中131I的监测结果与分析

目的 了解碘治疗工作场所空气中¹³¹I气溶胶的活度浓度,估算核医学科医务人员吸入¹³¹I所致内照射剂量。方法 使用CF-1001BRL型便携式大容量空气采样器,采用碘盒收集山东省6家医院核医学科碘治疗工作场所空气中的¹³¹I气溶胶,利用HPGe-γ能谱仪对样品进行测量,得到6家医院碘治疗工作场所中¹³¹I的活度浓度值,并估算医务人员的内照射剂量。结果 6家医院碘治疗工作场所空气中¹³¹I的活度浓度范围为3.64~2.94×10³Bq/m³,控制区（病房、患者通道、分装间、远程操作给药室）¹³¹I的浓度水平明显高于监督区,监督区¹³¹I的浓度最高的是医护通道,为2.62×10²Bq/m³。核医学科医务人员两种职业待积有效剂量估算值为0.07~5.68 mSv,均未超过国家规定限值。结论 医院核医学科碘治疗工作场所仍存在不可忽视的¹³¹I气溶胶污染现象,应面向全国各地区核医学科开展内照射监测,探索更加合理的防护标准和方法。     

两种便携式γ谱仪在放射工作人员甲状腺131 I内照射监测中适用性探讨

目的探讨便携式高纯锗(HPGe)γ谱仪与便携式溴化镧(LaBr)γ谱仪在测量放射工作人员甲状腺内131I活度和内照射监测中适用性的差别。方法分别使用DETECTIVE-DX100-KT便携式HPGe γ谱仪和InSpector 1000便携式LaBr γ谱仪测量放射工作人员甲状腺内131I含量, 比较不同设备的检测结果、最小可探测活度(MDA)以及对应的年待积有效剂量的差别。结果使用HPGe γ谱仪测量的放射工作人员甲状腺内131I检出率为67.7 %, 使用LaBr γ谱仪的检出率为26.2%。使用HPGe γ谱仪甲状腺部位MDA为12.26～14.74 Bq(测量时间3～5 min), LaBr γ谱仪的MDA为56.56 ～80.37 Bq(测量时间2～4 min)。以慢性连续摄入模式, 7 d为监测周期估算, 两种仪器的MDA对应的内照射年待积有效剂量分别为0.07～0.08 mSv(3～5 min)和0.31～0.45 mSv(2～4 min)。结论两种便携式γ谱仪在短时间测量时的最小可探测活度(MDA)均满足GBZ129-2016《职业性内照射个人监测规范》对于甲状腺体外监...     

核医学场所空气中131I浓度监测及工作人员内照射剂量评价探讨

目的 了解医疗机构¹³¹I治疗工作场所空气中¹³¹I核素的活度浓度水平，探讨通过空气采样方法估算工作人员内照射剂量的方法并分析其影响因素。方法 选取郑州市10家开展¹³¹I核素治疗的工作场所，采用空气采样方法采集¹³¹I治疗工作场所中放射性气溶胶，用高纯锗γ能谱仪进行γ放射性核素测定并推算工作场所空气中¹³¹I核素的活度浓度水平，根据测量结果和现场调查结果估算放射工作人员因¹³¹I核素吸入导致的内照射剂量。结果 19个分装间空气样品的¹³¹I活度浓度为0.087~570 Bq/m³，平均为（51.04±128.58）Bq/m³；11个病房空气样品的¹³¹I活度浓度为0.162~54.6 Bq/m³，平均为（7.97±15.89）Bq/m³。根据GBZ 129-2016《职业性内照射个人监测规范》推荐的典型工作时间估算，放射工作人员由于吸入¹³¹I核素导致的年待积有效剂量范围为2 μSv~10 mSv，平均为（0.61±1.80）mSv，年有效剂量均未超过国家标准所规定的剂量限值。结论 郑州市10家医疗机构核医学工作场所中¹³¹I核素活度浓度较高的样品多分布在甲状腺癌住院患者较多、核素操作量较大的三甲医院，由此导致的工作人员内照射剂量不容忽视。根据空气样品的测量结果估算内照射剂量带有很大不确定度，但空气采样方法可及时发现异常或事故情况下的放射性污染，为工作人员开展体外直接测量和内照射评价提供预警。     

河南郑州“7·20”特大暴雨灾害后核医学衰变池周围土壤中131I放射性水平调查及分析

目的探究"7·20"特大暴雨灾害后核医学衰变池是否存在放射性废水泄漏或溢出, 分析其发生原因, 为今后核医学衰变池的设计、建设、维护及核医学放射防护管理提供科学依据。方法选择郑州市3家开展131I治疗的医院(A、B、C医院), 根据核医学衰变池周围环境辐射水平检测结果按标准方法设置采样点位, 采集不同深度土壤样品。用高纯锗γ能谱仪测量土壤中131I的放射性水平, 对检测结果进行处理和分析。结果除B医院未检出131I放射性核素外, A和C医院核医学衰变池周围土壤中均检出不同活度浓度的131I放射性核素, A医院131I的活度浓度范围为16.4～98 111.8 Bq/kg, C医院131I的活度浓度范围为10.6～7 176.6 Bq/kg。经过一段时间衰变后, 对A医院和C医院进行复测, A医院131I的活度浓度范围为1.3～17.0 Bq/kg, C医院131I的活度浓度范围为3.9～7.1 Bq/kg。同一采样点位0～5 cm土壤中131I活度浓度均高于5～10 cm土壤中131I活度浓度, 两者比值范围为1.3～13.1, 比值中值为5.9。结论 "7·20"特大暴雨灾害后, 部...     

分化型甲状腺癌患者日尿排泄131I活度分数估算

目的 探讨甲状腺切除术后经131I治疗的分化型甲状腺癌(DTC)患者日尿排泄131I活度分数的估算方法.方法 建立优化隔室模型,并计算甲状腺癌患者日尿排泄131I活度分数,对20例经甲状腺切除术后的DTC患者日尿排泄131I累积活度进行检测,以验证该模型计算结果.结果 采用优化模型估算DTC患者服药后第1日尿排泄131I活度分数为58.2%,服药后初始5 d总尿排泄131I活度分数为79.3%;用γ计数仪实际检测DTC患者服药后第1日尿排泄131I活度分数均值为57.9%,服药后初始5 d总尿排泄131I活度分数均值为79.9%.结论 优化的DTC患者隔室模型计算日尿排泄131I活度分数简单方便,估算的日尿排泄131I活度分数值与实际检测结果吻合较好.该模型可用于估算经甲状腺切除术后的甲状腙癌患者日尿排泄131I活度分数,有助于放射性废物管理以及患者周围人员防护.     

便携式NaI (Tl)γ谱仪对甲状腺内131 I的探测效率模拟计算

目的 计算不同甲状腺-颈部刻度模体和测量位置对便携式γ谱仪的全能峰探测效率影响,为更加准确开展人体甲状腺内¹³¹I活度现场测量提供指导。方法 在对4种典型的甲状腺-颈部模体和用于甲状腺内¹³¹I活度测量的便携式3英寸NaI （TI）γ谱仪进行建模的基础上,结合可能的现场测量情景,利用蒙特卡罗方法模拟计算便携式NaI （TI）γ谱仪在不同测量距离、不同甲状腺深度、不同甲状腺体积等条件下的全能峰（364.5 keV）探测效率。结果 NaI （TI）γ谱仪的探测效率随探测器与颈部表面距离增加而显著递减,紧贴颈部表面的探测效率约为距颈部表面15 cm的15倍;探测效率随甲状腺深度增加而明显降低,在颈部表面测量时,深度为2 mm的探测效率约为30 mm的3.6倍;探测效率随甲状腺体积增大而减小,在颈部表面测量时,体积为1 ml的探测效率是30 ml的1.71倍;探测效率随探测器中心偏移而降低,尤其是在颈部表面测量时,中心偏离2 cm会导致探测效率下降约15%。结论 利用便携式NaI （TI）γ谱仪开展人体甲状腺内¹³¹I活度准确测量,不仅需要掌握探测效率刻度时的测量距离,还需了解所用刻度模体内的甲状腺深度与体积。     

131I胶囊和液体在家兔及人体代谢的对比研究

目的观察131I胶囊和液体在家兔和甲亢患者甲状腺吸131I率(TUR)的异同,建立测量131I胶囊TUR的方法.方法①家兔实验.6只家兔随机分为胶囊组和液体组(均予7.4 MBq 131I).行γ显像,计算TUR.②甲亢患者131I胶囊标准源测量.104例Graves甲亢患者,131I示踪和治疗剂量均采用胶囊给药,与均采用液体给药的118例患者进行治疗前后24 h TUR比较.结果①家兔甲状腺对131I胶囊和液体的2,4,6,24 h TUR均无差异.②131I胶囊标准源测量溶解计数较胶囊直接测量高(13.8±2.8)%,t=8.97,P<0.01.③甲亢患者胶囊组示踪剂量TUR为(71.4±10.9)%,治疗剂量TUR为(68.5±14.7)%(t=1.62,P>0.05.);液体组分别为(71.3±12.3)%和(65.1±13.0)%(t=3.82,P<0.01).示踪剂量24 h TUR在80.0%以上者,2组治疗剂量平均TUR均低于示踪剂量.结论①家兔对131I胶囊各时相TUR与液体比较无差异.②131I胶囊做标准源须溶解于甲状腺模型内.③胶囊剂型可以作为131I治疗甲亢的标准方法.④示踪量TUR 80.0%以上者2组示踪剂量TUR均高于治疗量TUR,注意加大131I投予量.     

接触131I放射性核素工作人员内照射剂量估算方法的初步研究

目的 探索接触¹³¹I放射性核素放射工作人员内照射剂量估算方法。方法 选择某¹³¹I放射性药物生产企业和某开展¹³¹I甲亢和甲状腺癌治疗的医院核医学科放射工作人员,使用便携式高纯锗（HPGe）γ谱仪,以7 d为周期,连续4次测量甲状腺部位¹³¹I活度,结合人员接触¹³¹I的轮岗方式,估算内照射剂量。结果 以监测月份为典型月份估算人员内照射剂量时,调查企业从事¹³¹I放射性药物分装的生产人员年待积有效剂量为0.09~1.93 mSv,调查医院核医学科工作人员内照射年待积有效剂量为0.06~0.58 mSv。对监测结果进行校正和结合轮岗方式后估算的工作人员内照射年待积有效剂量,放射性药物生产工作人员和核医学科工作人员分别为0.06~1.22 mSv和0.03~0.16 mSv。结论 在进行接触¹³¹I放射性核素工作人员内照射剂量估算时,仅以单次测量的结果估算全年受照剂量会带来较大的误差。在连续监测时,应根据前续监测周期的结果对后续监测周期结果进行校正。为准确估算人员内照射剂量,应充分考虑工作人员接触¹³¹I的方式、接触的时间、接触的频率、内污染的途径等因素。对于接触¹³¹I内照射剂量可能>1 mSv/年的工作人员,以14 d作为常规监测周期较为适宜。     

介入栓塞与^131I治疗Graves病近期疗效的对比分析

目的对比分析甲状腺动脉介入栓塞和131I治疗Graves病近期疗效的差异。方法对接受131I和甲状腺动脉栓塞治疗的各42例Graves病患者,行造影、SPECT/CT显像检查治疗前后甲状腺形态、大小,放射免疫法检测治疗前后3、6和12个月血清中FT3、FT4、TSH浓度及促甲状腺受体抗体(TRAb)活度和治疗后并发症出现的关系,并对以上数据进行统计学分析。结果两种治疗方法近期疗效无显著差异,介入治疗组治疗后早期严重并发症的发生率明显高于131I治疗组,而131I治疗组有更高的甲状腺功能减退(甲减)发生率。结论甲状腺动脉介入栓塞和131I治疗Graves病患者疗效肯定,131I可用于初诊及其他方法疗效不佳的患者,介入栓塞治疗可用于抗甲状腺药物疗效不佳、无法手术及甲状腺摄131I率低不能行131I治疗者,特别对一些难治性、顽固性甲状腺功能亢进有效。介入疗法可作为Graves病可选择的手段。     

99mTc-pertechnetate in the detection of thyroid carcinoma in a ten year period

During a 10-year period, 63 patients with thyroid malignancies were imaged with ^99mTc-pertechnetate (^99mTc) and 9 of them also underwent imaging with ¹³¹I. To evaluate ^99mTc in the detection of thyroid carcinoma, the scans were blindly analyzed and compared with the reports of surgeons and pathologists. The carcinomas were located in hypoactive nodules in 60 cases, there were cold nodules in the three remaining thyroids, but accurate localization of the carcinomas was not possible, however, it seemed that only one of these could have been situated either in a hot or a cold nodule. The ^99mTc and ¹³¹I images were almost the same. The most common carcinomas were papillary (46%) and follicular (38%) forms. More than one hypoactive nodule was detected in 48% of patients, two or more carcinoma nodules were noted in 17%, and multinodular goitre in 29% of patients. Our study confirms the usefulness of ^99mTc in carcinoma detection, we suggest that reimaging of all the functioning nodules on the ^99mTc scan with radioiodine, as recommended by many authors, is neither necessary nor justifiable.     

131I dose to the human fetal thyroid in the Zagreb district, Yugoslavia, from the Chernobyl accident

The 131I activity was measured in 30 human fetal thyroids in Zagreb district after the Chernobyl accident. A model of radioiodine metabolism in the mother and human fetus which takes into account the age dependence of the uptake and retention of radioiodine in the fetal thyroid was developed. Having assessed that the total intake by the average mother was about 1330 Bq, a good correlation between calculated and measured fetal thyroid activities was found (r = 0.77, P less than 0.001). The fetal thyroid dose reached the maximum of 0.43 micro Gy/Bq intake at about the fifth month of gestation. It was concluded that the risk of having a child with a harmful trait due to 131I absorbed by the mother was negligible.     

Iodine-123 as a diagnostic imaging agent in differentiated thyroid carcinoma: a comparison with iodine-131 post-treatment scanning and serum thyroglobulin measurement

Purpose Using ¹²³I for diagnostic purposes avoids the risk of stunning for subsequent radioiodine treatment and affords an excellent image quality. In this study we assessed the role of ¹²³I in comparison with ¹³¹I post-treatment imaging in patients with thyroid cancer. Methods We compared a total of 292 ¹²³I scans with their corresponding post-treatment ¹³¹I images. Patients received a therapeutic dose of ¹³¹I following diagnostic scanning with 50–111 MBq of ¹²³I. All patients were in a hypothyroid state (>30 μIU/l) before radioiodine administration for either diagnostic or therapeutic purposes. Results In 228 out of 263 patients with a positive diagnostic scan, ¹²³I whole-body scan findings were concordant with those of corresponding post-treatment ¹³¹I images (concordance rate 87%). However, there were 44 additional foci of abnormal uptake on post-treatment ¹³¹I scans in 22 discordant cases with no impact on therapeutic management of the patients. In 13 patients, there was at least one new site on post-treatment images that had been missed on pretreatment ¹²³I images. Twenty-nine patients with a negative diagnostic scan were treated with ¹³¹I owing to a high serum thyroglobulin level (range 11.3–480 ng/ml). Radioiodine uptake sites were seen in eight post-treatment scans. In 21 pairs of whole-body scans, both the pre- and the post-treatment scan were negative (concordance rate 72.4%). Conclusion ¹²³I scanning is comparable to high-dose ¹³¹I post-treatment imaging in thyroid carcinoma patients, and ¹²³I offers excellent image quality as a diagnostic agent. It avoids disadvantages such as stunning before treatment and delivery of a high radiation dose to patients.     

Significance of Salivary Gland Radioiodine Retention on Post-ablation 131I Scintigraphy as a Predictor of Salivary Gland Dysfunction in Patients with Differentiated Thyroid Carcinoma

Purpose

We investigated whether ¹³¹I whole-body scintigraphy could predict functional changes in salivary glands after radioiodine therapy.

Methods

We evaluated 90 patients who received initial high-dose (≥3.7 GBq) radioiodine therapy after total thyroidectomy. All patients underwent diagnostic (DWS) and post-ablation (TWS) ¹³¹I whole-body scintigraphy. Visual assessment of salivary radioiodine retention on DWS and TWS was used to divide the patients into two types of groups: a DWS+ or DWS- group and a TWS+ or TWS- group. Salivary gland scintigraphy was also performed before DWS and at the first follow-up visit. Peak uptake and %washout were calculated in ROIs of each gland. Functional changes (Δuptake or Δwashout) of salivary glands after radioiodine therapy were compared between the two groups.

Results

Both peak uptake and the %washout of the parotid glands were significantly lower after radioiodine therapy (all p values <0.001), whereas only the %washout were significantly reduced in the submandibular glands (all p values <0.05). For the parotid glands, the TWS+ group showed larger Δuptake and Δwashout after radioiodine therapy than did the TWS- group (all p values <0.01). In contrast, the Δuptake and Δwashout of the submandibular glands did not significantly differ between the TWS+ and TWS- groups (all p values >0.05). Likewise, no differences in Δuptake or Δwashout were apparent between the DWS+ and DWS- groups in either the parotid or submandibular glands (all p values >0.05).

Conclusion

Salivary gland radioiodine retention on post-ablation ¹³¹I scintigraphy is a good predictor of functional impairment of the parotid glands after high-dose radioiodine therapy.     

应对福岛核事故我国食品和饮用水的放射性监测

目的 汇总分析日本福岛核电站事故发生后我国沿海城市和主要内陆城市食品和饮用水放射性的抽样监测结果,评价是否对我国居民的健康造成影响.方法 根据国家标准方法,制定应对日本福岛核事故对我国食品和饮用水的监测方案,统一数据报送格式,对数据进行对比分析.结果 4月2日北京露天生长菠菜样品中,监测到极微量的人工放射性核素131I,此后在全国范围内10种露天生长的蔬菜中也检测出131I,最高值为菠菜样品3.1 Bq/kg,到5月初未再检测出.牛奶、海产品和饮用水样品中未检测到人工放射性核素.结论 监测到的蔬菜中131I来自日本福岛核电站事故释放,与此次事故期间欧洲一些国家食品中的的131I水平相一致,远低于1986年切尔诺贝利核电站事故时我国蔬菜中131I活度,其对公众所致吸收剂量极其微小,不会对我国境内公众造成影响.     

The role of thyroid scanning in hyperthyroidism

Radionuclide thyroid imaging was performed in 872 consecutive patients with hyperthyroidism. Of these, 84% were found to have diffuse toxic hyperplasia (Graves' disease), while 12% had autonomously functioning nodules (Plummer's disease), 3% had Graves' disease developing in a multinodular gland, and in the remaining 1%, either a clear diagnosis could not be established or the hyperthyroidism was due to thyroiditis or the Job-Basedow phenomenon. It was found that a thyroid scan seldom provides additional diagnostic information in patients with Graves' disease when a diffuse goitre is present. However, if patients are to be treated with radioiodine (¹³¹I), thyroid imaging with tracer quantitation can replace a 24-h ¹³¹I uptake measurement, this having the advantages that the patients are required to attend only once, and that the gland size can be measured. In addition, visual confirmation of tracer uptake by the thyroid is obtained and patients with thyroiditis will not receive inappropriate therapy. When single or multiple thyroid nodules are palpated, a thyroid scan is crucial in establishing an accurate diagnosis, as it is not otherwise possible to differentiate between Plummer's disease and Graves' disease developing in a multinodular gland. Indeed, in 20 of our 63 patients (32%) with single autonomously functioning nodules, the initial clinical assessment had been incorrect.