ABSTRACT
PURPOSE: Thallous-201 chloride produced at Korea Cancer Center Hospital(KCCH) is used in detecting cardiovascular disease and cancer. Thallium impurity can cause emesis, catharsis and nausea, so the presence of thallium and other metal impurities should be determined. According to USP and KP, their amounts must be less than 2 ppm in thallium and 5 ppm in total. In this study, the detection method of trace amounts of metal impurities in [201Tl]TlCl injection with polarography was optimized without environmental contamination. MATERALS AND METHODS: For the detection of metal impurities, Osteryoung Square Wave Stripping Voltammetry method was used in Bio-Analytical System (BAS) 50W polarograph. The voltammetry was composed of Dropping Mercury Electrode (DME) as a working electrode, Ag/AgCl as a reference electrode and Pt wire as a counter electrode. Square wave stripping method, which makes use of formation and deformation of amalgam, was adopted to determine the metal impurities, and pH 7 phosphate buffer was used as supporting electrolyte. RESULTS: T1, Cu and Pb in thallous-201 chloride solution were detected by scanning from 300 mV to -800 mV. Calibration curves were made by using TlNO3, CuSO4 and Pb(NO3)2 as standard solutions. Tl was confirmed at -450 mV peak potential and Cu at -50 mV. Less than 2 ppm of Tl and Cu was detected and Pb was not detected in KCCH-produced thallous-201 chloride injection. CONCLUSION: Detection limit of thallium and copper is approximately 50 ppb with this method. As a result of this experiment, thallium and other metal impurities in thallous-201 chloride injection, produced at Korea Cancer Center Hospital, are in the regulation of USP and KP. Polarograph could be applied for the determination of metal impurities in the quality control of radiopharmaceuticals conveniently without environmental contamination.
Subject(s)
Calibration , Cardiovascular Diseases , Catharsis , Copper , Electrodes , Hydrogen-Ion Concentration , Korea , Limit of Detection , Metals, Heavy , Nausea , Polarography , Quality Control , Radiopharmaceuticals , Thallium , VomitingABSTRACT
188Re (beta=22 MeV; gamma=155 keV; T1/2=16.9 hours) is an attractive therapeutic radioisotope which is produced from decay of reactor-produced tungsten-188 parent (T1/2=69 days). 188W has been produced from the double neutron capture reaction of 186W. 188Re can be easily obtained by elution of saline on alumina based 186W/188Re generator, which is commercially available. Complexes labelled with 188Re have been developed for the radiotherapy treatment of diseases because of the desirable nuclear properties of the radioisotope and it's chemical properties similar to those of technetium, a well established diagnostic agent.
Subject(s)
Humans , Aluminum Oxide , Neutrons , Parents , Radiotherapy , TechnetiumABSTRACT
I-123 labelled fatty acids are suitable for investigation of regional myocardial metabolism, so they are on the clinical trial. However, the precise properties of these materials are not characterized yet. We have synthesized phenylpentadecanoic acid and labeled this compound with I-123. The purpose of this study was to examine the stability, biodistribution, metabolism and SPECT imaging of [I-123]15-(p-iodophenyl)pentadecanoic acid(I-123-IPPA) that we made. The stability test of I-123-IPPA in serum of rat, mouse and human showed no free I-123 after 1 hour. In biodistribution study in mice for various time intervals after injection(5, 10, 15, 30, 60 minutes), uptake in myocardium was 14.5%ID/g(5 min), and 1.9%ID/heart(5 min), while uptake in muscles was 2.6%ID/g(5 min). Myocardium to blood ratio and myocardium to lung ratio increased for 5 min after injection and then decreased rapidly. Chromatographic data of rat blood and urine showed that little PPA was found in blood and urine 15-20 min after injection. The myocardial I-123-IPPA SPECT images of a dog with myocardial infarction showed defects similar to those of Tc-99m-MIBI and F-18-FDG. These data suggest that I-123-IPPA is quite stable in vitro and shows favorable biodistribution in mice. SPECT imaging with I-123-IPPA demonstrated infarct zone as photon defect in dog model of myocardial infarction. I-123-IPPA may be used for the evaluation of fatty acid metabolism in clinical trials in Korea.
Subject(s)
Animals , Dogs , Humans , Mice , Rats , Fatty Acids , Korea , Lung , Metabolism , Muscles , Myocardial Infarction , Myocardium , Tomography, Emission-Computed, Single-PhotonABSTRACT
PURPOSE: The aim of this sutdy was to evaluate the feasibility of 3-[131I]Iodo-O-methyl-L-a-methyltyrosine ([131I]OMINT) as an agent for tumor image. MATERIALS AND METHODS: After synthesis of 4-O-methyl-L-a-methyltyrosine (OMAMT), OMAMT was labeled with 131I using Iodogen method. In viro cellular uptake study was performed using 9 L gliosarcoma cells at various time points upto 4 hr. The biodistribution (five rats implanted with the 9 L gliosarcoma cells per group) was evaluated at 30 min, 2 hr, 24 hr after iv injection of 3.7 MBq [131I]OMIMT or L-3-[131I]iodo-a-methyltyrosine ([131I]IMT). Gamma camera images were obtained at 30min, 2 hr, and 24 hr. RESULTS: [131I]OMINT uptake was 3.3 times and 2.5 times higher than [131I]IMT uptake at 30 min and 60 min, respectively and same after 2 hr in in vitro sutdy using 9L gliosarcoma cells. Maximum accumulation in tumor occurred at 30 min for both [131IOMINT and [131I]IMT in tumor bearing rats. The tumor uptake of [131I]OMINT was significantly higher than that of [131I]IMT in tumor bearing rats. The tumor uptake of [131I]OMIMT was significantly higher than that of [131I]IMT at early time point studied (3.74 +/- 0.48 vs 0.38 +/- 0.17% ID/g at 30 min and 2.40 +/- 0.17 vs 0.24 +/- 0.03% ID/g at 2 hr, respectively, p<0.01). However, the tumor uptake of both radiolabels were not significantly different at 24 hr (0.04 +/- 0.01 vs 0.05 +/- 0.01% ID/g). Tumor was visualized as early as at 30 min in gamma camera images. CONCLUSION: These data suggested that [131I]OMIMT might be a useful tumor imaging agent and has more advantage for the tumor imaging compared to [131I]IMT.