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。     

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。     

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。     

青岛市大气气溶胶中210Pb活度浓度变化特征及辐射剂量估算

目的 了解青岛市大气气溶胶中²¹⁰Pb的变化特征,评估吸入²¹⁰Pb对人体辐射的影响。方法 利用高纯错（HPGe）γ能谱仪测量采集的气溶胶样品来监测2015年4月至2016年3月青岛市大气气溶胶中²¹⁰Pb的活度浓度。结果 监测期间大气气溶胶中²¹⁰Pb活度浓度的变化范围为0.06~1.61 mBq/m³,平均值为（0.70±0.50）mBq/m³。大气气溶胶中放射性核素²¹⁰Pb的活度浓度2015年12月至2016年2月较高,8月至11月较低。气溶胶中²¹⁰Pb对成年人年待积有效剂量贡献为6.35×10^-6 Sv。大气气溶胶中²¹⁰Pb活度浓度平均值稍高于联合国原子辐射影响科学委员会（UNSCEAR）1988年报告书给出的全球近地面大气²¹⁰Pb平均活度浓度推荐值（0.50 mBq/m³）。青岛市大气气溶胶中²¹⁰Pb活度浓度月变化与厦门市具有相似规律。结论 青岛市大气气溶胶中²¹⁰Pb变化特征与大气环境污染状况具有一致性。气溶胶中²¹⁰Pb对成年人年待积有效剂量贡献比较低。但对于长期处于较高²¹⁰Pb活度浓度空气环境中的人群,²¹⁰Pb沉积在肺部的长期辐射影响应引起重视。     

2017—2020年北京地区大气气溶胶中7 Be和210 Pb放射性活度浓度监测与分析

目的 监测与分析2017—2020年北京地区大气气溶胶中⁷Be和²¹⁰Pb放射性活度浓度变化情况,为有效防治空气污染提供科学依据。方法 利用大流量空气气溶胶采样器（SnowWhite）采集气溶胶样品1 074份,其中春季、夏季、秋季和冬季分别采集275、266、262和271份。使用低本底高纯锗伽马谱仪（ORTEC）分析气溶胶样品中⁷Be和²¹⁰Pb放射性活度浓度。结果 2017—2020年北京地区大气气溶胶中⁷Be放射性活度浓度的变化范围为0.56~14.84 mBq/m³,平均值为6.84 mBq/m³。²¹⁰Pb放射性活度浓度的变化范围为0.01~9.37 mBq/m³,平均值为3.19 mBq/m³。2017—2020年北京大气气溶胶⁷Be和²¹⁰Pb放射性活度浓度在春、夏、秋、冬四季中差异均有统计学意义（F=32.66、93.93,P<0.05）,其中⁷Be放射性活度浓度春季最高,秋季次之,夏季和冬季最低,²¹⁰Pb放射性活度浓度由高到低分别为冬季、秋季、春季、夏季。结论 2017—2020年北京地区大气气溶胶中⁷Be和²¹⁰Pb放射性活度浓度处于正常涨落水平范围内。     

分化型甲状腺癌患者131I治疗后体内放射性总活度的变化及影响因素

目的 探讨¹³¹I治疗分化型甲状腺癌(differentiated thyroid carcinoma,DTC)术后患者体内放射性总活度的变化及其代谢的影响因素。方法 回顾性分析2021年9月至2022年4月于空军军医大学第二附属医院核医学科接受¹³¹I治疗的218例DTC术后患者的临床资料,根据服用¹³¹I的剂量分为低剂量组(≤3.7 GBq)171例和高剂量组(＞3.7 GBq)47例,使用全身动态辐射监测系统在服用¹³¹I后24、48及72 h测定体内¹³¹I残留活度并探讨其变化的影响因素。结果 服用¹³¹I后低剂量组24、48及72 h的体内¹³¹I残留活度均明显低于高剂量组(t=-7.46、-3.31、-2.01,P<0.05);低剂量组24、48 h出院达标率明显高于高剂量组(21.0%vs. 4.3%、98.2%vs. 89.4%,χ²=7.23、5.91,P<0.05),且所有患者在72 h均可达出院标准。单因素分析显示患者24及48 h体内¹³¹I残留活度与年龄、体质量指数(body mass index,BMI)、基础代谢率(basal metabolism rate,BMR)及促甲状腺激素(thyroid stimulating hormone,TSH)有关。多元线性回归分析显示低剂量组24 h时年龄越大、BMR越高、TSH水平越高,体内¹³¹I残留活度越大,48 h时BMI越大、TSH越高,体内¹³¹I残留活度越大;高剂量组24 h时年龄越大、BMR越高,体内¹³¹I残留活度越大。患者体内¹³¹I残留活度达到400 MBq的时间以24、36 h来分析其影响因素,结果显示以24 h为分界时,TSH水平越低,体内¹³¹I残留活度越低;以36 h为分界时,年龄越小、TSH水平越低、¹³¹I治疗剂量越小,体内¹³¹I残留活度越低。结论 年龄、BMI、BMR及TSH水平是¹³¹I治疗DTC术后患者体内放射性总活度的影响因素,联合上述指标进行辐射剂量评估可为调整患者住院时长提供参考。     

分化型甲状腺癌患者131I治疗后体内残留放射性活度的评估

目的 评估分化型甲状腺癌(DTC)患者¹³¹I治疗后体内残留放射性活度.方法 本次前瞻性研究包括49例DTC患者,分为“清甲”(¹³¹I摧毁术后残留的甲状腺组织)与“清灶”(¹³¹I治疗甲状腺床残留甲状腺癌、甲状腺床复发灶和转移灶)组,于服¹³¹I后收集患者每次排泄尿液,测定患者每天每次通过尿液排泄的放射性活度及排泄的总放射性活度,进而估算患者体内残留的放射性活度.分别于服¹³¹I后2、6、24、48、72 h进行1 m处剂量当量率的测定,估算患者体内残留放射性活度达到400 MBq时1 m处剂量当量率.结果 服¹³¹I后2、6、24、48、72 h体内残留¹³¹I活度占服¹³¹I初始活度的百分比,“清甲”组分别为99%、72%、25%、15%、7%,1 m处剂量当量率分别为157、120、35、11、9 μSv/h;"清灶"组对应百分比分别为99%、71%、18%、7%、3%,1 m处剂量当量率分别为232、182、48、11、2 μSv/h.体内残留的放射性活度与1 m处剂量当量率呈正相关(r=0.94,P<0.001).“清甲”与“清灶”组服¹³¹I后48~72 h体内残留放射性活度分别为548~259及451~248 MBq,对应的1 m处剂量当量率为8~10 μSv/h.结论 DTC患者于服¹³¹I后48~72 h体内残留放射性活度达到国家标准规定的400 MBq,即DTC患者1 m处剂量当量率达到8~10 μSv/h方可出院.     

北京春季室外空气中210Pb放射性水平测量与分析

目的 测量分析北京春季室外空气中放射性核素²¹⁰Pb水平。方法 采用便携式大流量空气采样器采集室外近地面空气气溶胶,利用高纯锗（HPGe）γ能谱仪测量气溶胶样品中²¹⁰Pb活度浓度。结果 2015年春季北京室外空气中²¹⁰Pb活度浓度范围值267.2~1 697.6 μBq/m³,均值为（878.7±386.7）μBq/m³,不同空气质量条件下空气中²¹⁰Pb活度浓度有差异。结论 北京春季室外空气中能够检出²¹⁰Pb,其活度浓度情况变化较大,但仍处于正常范围。     

6家医院碘治疗场所工作人员甲状腺131I活度测量

目的调查碘治疗场所工作人员甲状腺131I活度水平及其主要影响因素。方法采用配额抽样的方法, 按照碘治疗场所医院的不同类型, 在山西省和山东省共选择6家开展碘治疗的医院, 采用直接测量法, 对76名碘治疗场所工作人员的甲状腺131I活度进行了测量, 并进行内照射剂量估算。结果共有5家医院的29人甲状腺131I活度高于仪器的探测限, 占全部被检测人员的38.16%, 其中最高值为2 468.45 Bq, 是1名负责手动分装放射性碘的医师。6家医院碘治疗场所工作人员甲状腺131I活度差异无统计学意义(P>0.05), 但手动分装131I的医院测量结果高于自动分装的医院, 差异有统计学意义(Z=1.75, P<0.01), 两家手动分装131I医院的12名碘治疗场所工作人员甲状腺测量结果全部高于探测限, 中位数分别为324.59 Bq和331.98 Bq, 4家使用自动分装仪的医院测量结果的中位数均低于探测限, 甲状腺131I检出率分别为32.61%、25.00%、10.00%和0。对于同一家医院, 参与分装131I的医生和保洁人员甲状腺131I活度高于不参与分装的医生, 差异有统...     

分化型甲状腺癌患者口服131I后体内活度变化及剂量水平

目的 研究¹³¹I治疗分化型甲状腺癌（DTC）患者体内放射性活度及外部剂量水平的变化规律，分析二者之间的关系，并估算400 MBq患者剂量当量率的修正因子。方法 研究对象为43例甲状腺全切术后，首次行¹³¹I"清甲"治疗的DTC患者，服药量为1 850~3 700 MBq，平均服药量（2 405±777）MBq。分别于口服¹³¹I后2、6、20、22、24、27、30、44、46、48、54、68及72 h，测定患者的体内剩余放射性活度以及患者前部0.3、1及3 m处的剂量当量率。结果 患者服¹³¹I后的体内剩余放射性活度随时间变化函数为A=A₀（1.033 16e^{-0.062 4t}+0.017 17）。可估算出"清甲"治疗的DTC患者有效半减期为12.19 h，体内放射性活度降至400 MBq仅需26.4~38.9 h。患者服用¹³¹I后距其0.3、1及3 m的标准化剂量当量率随时间变化函数分别为：Ḣ_0.3=127.220 7e^{-0.054 8t}+3.765 71、Ḣ₁=30.225 8e^{-0.064 4t}+0.824 67、Ḣ₃=4.161 9e^{-0.061 5t}+0.167 97。患者服¹³¹I后体内剩余放射性活度与1 m处剂量当量率呈正相关（r=0.982，P<0.05），函数为Ḣ₁=0.025A+1.245。DTC患者体内剩余活度分别为1 000、700和400 MBq时，距患者1 m处对应的剂量当量率分为26.2、18.7和11.2 μSv/h。估算活度为400 MBq的患者0.3、1及3 m处剂量当量率的修正因子分别为0.25、0.49及0.70。结论 服用¹³¹I活度在3 700 MBq以下的DTC患者仅需住院2日便可达到出院标准。当DTC患者体内活度降至400 MBq时，其1 m处的剂量当量率远小于25 μSv/h。单纯利用点源公式估算患者周围剂量当量率会造成高估的情况，因此对于公式估算患者周围辐射水平时使用的修正因子还需进一步研究，使模型估算结果更贴合实际情况。     

人体中的镭-226、镭-228、钋-210、铅-210

本文报道了广东阳江高本底地区6名、对照地区8名人尸体的骨²²⁶Ra、²²⁶Ra的浓度以及部分居民内脏器官中。²¹⁰Po、²¹⁰Pb的浓度。结果轰明阳江高本底地区和对照地区居民骨镭-226、镭-228的浓度分别为29.9pCi/kg, 26.9pCi/kgl 8.7pCi/kg, 8.2pCi/kg.由此估算出阳江高本底地区屠民骨中²²⁶Ra、²²⁸Ra的负薄璧及对骨衬、骨髓所产生的剂量当量分别为对照地区民民的3.4倍, 3.3倍。两地区居民内脏器官中^{210Po、210Pb的测定分析铡数较少但仍看出, 高本底地区均明显高于对照地区.}     

Production of large quantities of 90Y by ion-exchange chromatography using an organic resin and a chelating agent

The performance of a system composed of an organic cation exchanger (Dowex 50Wx8) and a chelating agent (EDTA) previously described for the successful production of (90)Y via a (90)Sr/(90)Y generator is assessed under dynamic conditions. In an attempt to overcome the established limitation of ion-exchange resins for the separation of subcurie quantities of activity, (90)Y is repeatedly isolated from an 11.8-GBq (320 mCi) (90)Sr cow using a three-column tandem arrangement. The high recovery and radionuclidic purity obtained for (90)Y and the parameters of the separation (time, eluant concentration, pH and flow rate range) strongly suggest that Ci quantities of (90)Y can be handled satisfactorily by the ion-exchange method. No replacement or treatment of the cow, low waste generation and (90)Sr losses less than 0.1% after each run were observed during the present study which, in combination with the low cost of this resin, may result in an attractive alternate method for the production of large quantities of (90)Y.     

Comparison of extraarticular leakage values of radiopharmaceuticals used for radionuclide synovectomy

OBJECTIVES: Radionuclide synovectomy is a reliable therapy in patients with chronic synovitis. However, radiation doses delivered to non-target organ systems due to leakage of radioactive material from the articular cavity are an important disadvantage of this procedure. In this study we compared extraarticular leakage values of the 3 commonly used radiopharmaceuticals; 90Y-citrate, 90Y-silicate and 186Re-sulfide colloid. MATERIALS AND METHODS: Thirty-five patients with persistent synovitis were enrolled in the study. Twenty-two hemophilic, 8 rheumatoid arthritis and 5 patients with pigmented villonodular synovitis were studied. 90Y labeled silicate and citrate were used for knee joints and 186Re-sulfide for intermediate sized joints. Radiocolloid leakage values were evaluated using a gamma camera with 20% window centered over the bremsstrahlung photopeak of 90Y and a respective window over the 137 keV photopeak of 186Re. Regions of interest were drawn over the injection site, the regional lymph nodes and the background areas. Leakage of radiocolloid was calculated by dividing the counts/pixel in the regional lymph node area to the counts/pixel in the injection site. RESULTS: No visible leakage was observed. The median leakage values calculated for 90Y-citrate, 90Y-silicate and 186Re-sulfide were found as 1.9%, 2.4% and 2.7%, respectively. The difference between the variability of leakage values was not statistically significant (p > 0.05). CONCLUSION: There was no significant difference in terms of extraarticular leakage between 9Y-citrate, 9Y-silicate and 186Re-sulfide radiocolloids.     

Radiobiological Issues in the Anomalous Enhanced Effect of Low-dose-rate Fission-spectrum Neutrons: Reply to Letter to the Editor by G. W. Barendsen

Summary

The influence of diet or its ingredients on ¹⁴¹Ce absorption and retention was investigated in six-day-old rats. Animals were fed over 8 h with cow's milk, rat diet or a mixture of rat diet ingredients (fish meal, sunfiower meal, alfalfa, cane molasses and premix) labelled with ¹⁴¹Ce. Whole-body radioactivity was determined in a double crystal scintillation counter every 24 h over a six-day period. Gut, liver, kidney and femur retention and cerium distribution in the gut was determined at the end of the experiment. Compared to milk diet, administration of rat diet or ingredients caused respectively 3 and 7·5 times lower whole body retention. Carcass retention was reduced by rat diet or ingredients 2–3 times and intestinal retention 3 and 8 times respectively. Irrespective of the dietary treatment the main site of cerium intestinal retention was the ileum. Our present results indicate that some compounds of rat diet might be considered as a means of reducing cerium absorption and intestinal retention in the very young.     

226Ra 228Ra 210Pb和210Po在水生生物及食物链中转移规律的探讨

目的 为了解天然放射性核素²²⁶Ra、²²⁸Ra、²¹⁰Pb与²¹⁰Po在水生物及食物链中转移和蓄积情况。方法 定点采集养殖水产品及栖息环境中水与底质沉积物, 按不同的实验需要, 每个鲜样分别剥取肉, 骨(壳),鳞片和胃肠。烹饪样品, 洗净、称重、清炖, 熟后分离出骨(壳),余为食物。样品分别测定²²⁶Ra、²²⁸Ra、²¹⁰Pb和²¹⁰Po含量。数据按统计学要求处理, 配对数据, 作了配对显着性检验。结果 ²²⁶Ra、²²⁸Ra和²¹⁰Pb主要沉积于骨(壳)中, 浓集系数为10²～10³,肉中为10⁰～10².²¹⁰Po主要蓄积在水生物胃肠中, 浓集系数在10²～10⁴,鱼类胃肠与贝类肉中可达10⁴.水产食品烹饪加工过程²²⁶Ra、²²⁸Ra和²¹⁰Pb在食物链中转移不明显, 经配对显着性检验, 差异无显着性(P0.05);然而210Po在淡水鱼类和虾类中转移是明显的, 肉配对检验有非常显着性差别(P<0.01).结论水生物对²²⁶Ra、²²⁸Ra、²¹⁰Pb和²¹⁰Po有很强浓集能力。     

Scintigraphic findings of MALT lymphoma of the thyroid

Mucosa-associated lymphoid tissue (MALT) lymphoma has been established as a distinct entity among non-Hodgkin's lymphomas, and the most common primary site is the stomach. We describe scintigraphic findings in a patient with MALT lymphoma of the thyroid. A 71-year-old woman with Hashimoto's thyroiditis suffered from rapid cervical swelling, and ultrasonography and CT revealed a thyroid nodule. The nodule showed accumulation of 99mTc pertechnetate comparable to the surrounding thyroid tissue, mimicking a benign nodule. Both 67Ga and 201Tl imaging visualized the lesion as an increased uptake area. After radiotherapy, abnormally increased uptake disappeared on 67Ga images, which predicted a favorable outcome. MALT lymphoma of the thyroid may be visualized as a warm nodule on 99mTc pertechnetate scintigraphy.     

Rapid synthesis and in vitro and in vivo evaluation of folic acid derivatives labeled with fluorine-18 for PET imaging of folate receptor-positive tumors

In an attempt to visualize folate receptors that overexpress on many cancers, [¹⁸F]-fluorobenzene and pyridinecarbohydrazide-folate/methotrexate conjugates ([¹⁸F]-1, [¹⁸F]-2-folates and [¹⁸F]-8, [¹⁸F]-9-MTXs) were synthesized by the nucleophilic displacement reactions using ethyl-trimethylammonium-benzoate and pyridinecarboxylate precursors. The intermediates ethyl [¹⁸F]-fluorinated benzene and pyridine esters were reacted with hydrazine to produce the [¹⁸F]-fluorobenzene and pyridinecarbohydrazides, followed by coupling with N-hydroxysuccinimide-folate/MTX. Radiochemical yields were greater than 80% (decay corrected), with total synthesis time of less than 45 min. Radiochemical purities were always greater than 97% without high-performance liquid chromatography purification. These synthetic approaches hold considerable promise as rapid and simple method for the radiofluorination of folate derivatives with high radiochemical yield in short synthesis time. In vitro tests on KB cell line showed that significant amount of the radioconjugates were associated with cell fractions, and in vivo characterization in normal Balb/c mice revealed rapid blood clearance of these radioconjugates with excretion predominantly by the urinary and partially by the hepatobiliary systems. Biodistribution studies in nude mice bearing human KB cell line xenografts demonstrated significant tumor uptake and favorable biodistribution profile for [¹⁸F]-2-folate over the other conjugates. The uptake in the tumors was blocked by excess coinjection of folic acid, suggesting a receptor-mediated process. Micro-positron emission tomography images of nude mice bearing human KB cell line xenografts confirmed these observations. These results demonstrate that [¹⁸F]-2-folate may be useful as molecular probe for detecting and staging of folate receptor-positive cancers, such as ovarian cancer and their metastasis as well as monitoring tumor response to treatment.     

Rapid determination of Sr impurities in freshly “generator eluted” Y for radiopharmaceutical preparation

⁹⁰Y is one of the most useful radionuclides for radioimmunotherapeutic applications and has a half-life (t_1/2=64.14 h) suitable for most therapeutic applications, beta particles of high energy and decays to a stable daughter. It is significant that ⁹⁰Y is available conveniently and inexpensively from a radionuclide “generator” by decay of its parent, ⁹⁰Sr. Nevertheless, current and planned clinical applications with [⁹⁰Y] labelled compounds employ activity levels that cannot be readily obtained from an in-house generator, but from commercial sources. We have evaluated Eichrom's Sr-resin, either as an “in-house” generator or as a fast QC method for analysis of ⁹⁰Y solutions.In particular, for the development as a generator, we investigated the percentage of the radio-Sr in the first 8 M HNO₃ eluate: in this fraction the concentration of ⁹⁰Sr must be smaller than 10⁻⁵% (recommendations of the International Commission on Radiological Protection). For evaluation as a rapid QC method, we analyzed the concentration of ⁹⁰Y in all the fractions containing “only” radio-Sr: ⁹⁰Y should not be present in these eluates. After the collection of β⁻ and γ spectra and analysis of them, we concluded that commercial Sr-resin minicolumn cannot give us the results expected; we developed an in-house system loaded with 4 mL of Sr-resin which gave better results as a generator and a rapid QC method.     

The role of I-131-MIBG in the diagnosis and therapy of carcinoids

The successful use of ¹³¹I-MIBG for the diagnosis and treatment of pheochromocytoma and neuroblastoma has led to its application in patients with carcinoid, another neural crest tumor. The present report describes the scintigraphic findings, in correlation with clinical and biochemical parameters, in 20 patients with histologically proven carcinoids. ¹³¹I-MIBG total body scintigraphy was positive in 12 and equivocal in 1 of 19 patients with metastases. The necessity of delayed imaging and the possible advantage of single photon emission tomography for the detection of this tumor are emphasized. The results of ¹³¹I-MIBG treatment in five patients with progressive carcinoid metastases are discussed. It is concluded that ¹³¹I-MIBG has a role in the work up of patients with proven carcinoid and can be used for palliative treatment of this tumor.     

Development of a modular system for the synthesis of PET [C]labelled radiopharmaceuticals

[¹¹C]labelled radiopharmaceuticals as N-[¹¹C]methyl-choline ([¹¹C]choline), l-(S-methyl-[¹¹C])methionine ([¹¹C]methionine) and [¹¹C]acetate have gained increasing importance in clinical PET and for the routine production of these radiopharmaceuticals, simple and reliable modules are needed to produce clinically relevant radioactivity. On the other hand, flexible devices are needed not only for the routine synthesis but also for more complex applications as the development of new tracers. The aim of this work was the adaptation of an Eckert Ziegler modular system for easy routine synthesis of [¹¹C]choline, [¹¹C]methionine and [¹¹C]acetate using components that account for straightforward scaling up and upgrades.