Isotopic ratios of129I/127I in mammalian thyroid glands in Japan

The isotopic ratios of¹²⁹I/¹²⁷I in cattle thyroid glands collected from various areas of Japan were measured by neutron activation analysis with combustion pre-treatment. Pig and human thyroid glands were also analyzed by the same method. The iodine isotopic ratio in cattle thyroid glands in Japan is comparable with that observed in Europe. The isotopic ratio in human thyroid glands in Japan is remarkably lower than that in Europe, which has been reported to be comparable to that of cattle. The isotopic ratio in pig thyroid glands is also lower than that in cattle.     

Correlation between gastrointestinal absorption and uptake of radioisotopes by the critical organs

This study was undertaken to investigate the correlation between gastrointestinal absorption of radioisotopes and uptake by the critical organ during the same period using 85Sr, 109Cd, 131I and 203Hg as radioisotopes. When the distribution of 85Sr, 109Cd, 131I and 203Hg in mice were investigated by means of the whole body autoradiography, these critical organs were determined as follows; 85Sr: bone, 109Cd: liver, 131I: thyroid gland and 230Hg: kidney. When the correlation between the injected dose and the uptake dose by the critical organ of 85Sr, 109Cd, 131I and 203Hg were investigated, uptake dose the critical organ expressed as cpm per gram of organ was in direct proportion to the injected dose and that expressed as % of the injected dose per gram of organ was held constand in either case. When the coefficient of correlation between gastrointestinal absorption and uptake by the critical organ of 85Sr, 109Cd, 131I and 203Hg were calculated, a positive correlation was revealed in either case. It is concluded from the results obtained that in vivo or in situ method, gastrointestinal absorption of radioisotopes received a support from uptake by the critical organ during the same period.     

Contribution of nuclear medicine procedures to global129I inventory

¹²⁹I content of batches of Na¹³¹I vials, used for nuclear medicine procedures, was estimated by neutron activation analysis. The average value of the¹²⁹I/¹³¹I activity ratio /corresponding to zero decay time of the latter/ was /4.98±2.8/x10^–9. It is concluded that the contribution of¹²⁹I from medical applications of¹³¹I in India is insignificant in relation to that from nuclear fuel cycle activities.     

Thallium-201 chloride dynamic analysis using thallium-201 chloride and sodium iodide-131 thyroid subtraction scintigraphy

The mechanism of 201Tl chloride accumulation is unclear in thyroid gland and thyroid tumor. This report examines 108 patients that received thyroid scintigraphy examinations with both 201Tl chloride and sodium 131I. The patients were diagnosed clinically and histologically whenever possible. The ROI were obtained by subtraction imaging with both isotopes and by subtraction positive and negative areas of imaging. Dynamic curves were obtained for 201Tl chloride per square unit of each ROI. The dynamic curve in the radioiodide-accumulated area was examined. The data indicate that the clearance rate of 201Tl chloride (T15) was correlated with the sodium 131I uptake rate at 24 h (r = 0.70).     

Sensitivity study on modeling radioxenon signals from radiopharmaceutical production facilities

As part of the Comprehensive Nuclear Test-Ban Treaty (CTBT), the International Monitoring System (IMS) was established to monitor the world for nuclear weapon explosions. As part of this network, systems are in place to monitor the atmosphere for radioxenon. The IMS routinely detects radioxenon from sources other than nuclear explosions. One of these radioxenon sources is radiopharmaceutical production facilities. This is a sensitivity study on the nuclear forensic signals possible from such facilities. A fission process model was produced to calculate the activity of ^131mXe, ^133mXe, ¹³³Xe and ¹³⁵Xe in the process utilized to produce ⁹⁹Mo and ¹³¹I for medical applications through high enriched uranium fission. The computer model accounts for fractionation of radionuclides within a decay chain that may result from filtering or chemical procedures. Ratios of the radioxenon isotopes are calculated as a function of decay time after the release. The ratios are then compared to those expected from nuclear explosions. The main conclusion from this work is that the two main factors that affect the nuclear forensic signal from radiopharmaceutical production facilities are the sample irradiation time and the use of emission gas storage tanks.     

Estimation of absorbed dose in 131I therapy of metastasis of thyroid cancer

The radiation absorbed dose was estimated for 131I therapy of metastatic lesions of thyroid cancer, by the quantitative gamma-camera imaging. Uptake for eleven lesions in five cases (out of four patients) was measured for two times after 131I administration. Activities were calculated from opposed images with corrections for distance and depth using empirical formulae. An activity time curve was assumed as a reminder of two exponentials and fitted to measured values. The sizes of lesions were evaluated using the multi-slice CT images. An increase of frequency of activity measurement, particularly within a few days after 131I administration is desirable, for the purpose of an improvement of accuracy of dosimetry.     

The radiotoxicology of iodine

Thirty radioisotopes of iodine are known but only those with mass numbers from 123 to 135 are of major radiotoxicological interest. Exposure of animals or man to inorganic¹³¹I or¹²⁵ I may result in the induction of benign or malignant thyroid tumors or depression of thyroid function; Bq for Bq¹²⁵I is less toxic than¹³¹I. However, the shorter lived radioiodines¹³²I,¹³³I, and¹³⁵I appear to be 10 to 100 X more toxic than¹³¹I alone. Adrenal, pituitary and ovarian tumours, as well as parathyroid hypofunction and other biochemical disturbances, have been reported in animals but not, so far, in man. Gonad doses from¹³¹I up to at least 800 mGy do not appear to cause in man an increased incidence of congenital abnormalities or spontaneous abortions. Little information is available about the toxicity of radioiodine containing organic compounds. The DNA precursor, iododeoxyuridine when labelled with¹²⁵I becomes incorporated into the cell nucleus and produces severe and often irreparable damage due to the emission of Auger electrons. The risk estimate for the induction of thyroid carcinoma or adenoma by inorganic¹³¹I is considered to be 10 to 20·10⁻⁶ persons Gy⁻¹ y⁻¹, but may be up to 100 times larger for persons exposed to mixtures of short-lived radioiodines.     

Preparation and evaluation of <Superscript>131</Superscript>I-quercetin as a novel radiotherapy agent against dedifferentiated thyroid cancer

Here we reported the radiolabeling and evaluation of a novel ¹³¹I-radiolabeled quercetin for the treatment of dedifferentiated thyroid cancers. The human thyroid cancer cell lines (FTC-133, TT and DRO) experienced much higher uptake of ¹³¹I-quercetin as compared to the free ¹³¹I. And the proliferation inhibition rate of ¹³¹I-quercetin on in vitro DRO cell line was 86.87 ± 7.15%. Biodistribution and SPECT analysis demonstrated that the injected radioactivity mainly accumulated in tumors. The tumor volume in the treatment group was dramatically inhibited in comparison with the control group.     

Determination of some trace elements in the thyroid gland by INAA

Neutron activation analysis without radiochemical separation was used for simultaneous analysis of eight trace elements in thyroid glands, obtained as necroptic material from persons not suffering from diseases of this gland. Inorganic standard solutions were used for calculations of concentrations of measured elements. Concentrations are expressed in ppm, or ppb. IAEA reference materials were used for quality assurance of analyses. From analyses of 42 thyroids concentration levels of Se, Cs, Sc, Fe, Cr, Zn, Co, and Rb and their variances in the thyroids were calculated. These results might serve as comparison material for medical research of pathological and functional changes in thyroid glands.     

131I标记海藻酸钠包裹明胶微球的制备及性能评价

建立了明胶微球和海藻酸钠(SA)包裹微球的制备方法,并通过实验比较了明胶微球和包裹微球的各种特性,最后用氯胺T法将125I及131I分别标记在微球上.结果表明,包裹微球对碘有更高的负载量和稳定性;在相同条件下,包裹微球的降解时间比明胶微球的降解时间长;将标记后的明胶微球通过直接注射介入到新西兰大白兔的肝脏,采用发射单光...     

Clinical evaluation of thyroid imaging with 201T1-chloride.

Clinical value and limitation of thyroid imaging with 201T1Cl were studied. The positive rate of 201T1 was 82% in 22 malignant thyroid lesions and 46% in 37 benign lesions. A 201T1 positive image was obtained when a lesion was parenchymatous and a 201T1 negative one when it was cystic, filled with colloid or hyaline and had massive necrosis or bleeding. Thus 201T1Cl localized in a parenchymatous lesion and did not in a nonparenchymatous one regardless of a malignant or benign disease. An increasing positive lesion in contrast with the surrounding thyroid tissue implies that it may be malignant and a decreasing one benign as a results of review of serial scintiphotos. Scintigraphic methods with 131I and 201T1 are complementary each other and a 201T1 negative image itself has a high diagnostic value but it seems to be better to attach much value to the finding of imaging with 131I when a 201T1 positive image is obtained.     

Radioiodination of insulin using N-succinimidyl 5-(tributylstannyl)-3-pyridine-carboxylate (SPC) as a bi-functional linker: Synthesis and biodistribution in mice</p> </p>

Summary Insulin receptors are overexpressed on a number of human tumors, leading to significant affinity of insulin to these tumors. It is appealing to receptor-targeted radiotherapy for malignant tumors if insulin is labeled with suitable radionuclide. In this paper, N-succinimidyl 5-(tributylstannyl)-3-pyridinecarboxylate (SPC), a potential bi-functional linker for radioiodination of proteins or peptides, was synthesizedby using 5-bromonicotinic acid as the starting material. Then, with this bi-functional linker, insulin was conjugated with ¹³¹I, and the tissue distribution of the labeled insulin (¹³¹I-SIPC-insulin) in normal mice was investigated. The results showed that insulin ^</span> could be conjugated with¹³¹I using SPC as the linker ^</span> in a labeling yield of40-58%, and with radiochemical purity of more than 98% after purification bySephadex?G-10. Even kept at room temperature for 72 hours, the radiochemical purity of ¹³¹I-SIPC-insulin was still more than 97%, implying that the conjugated insulin was constantly stable in vitro.Meanwhile, in order to evaluate the in vivo stability of the conjugated compounds, insulin was also labeled with ¹³¹I by a direct method using chloramine-T (Ch-T) as the electrophilic agents.Biodistribution of¹³¹I-SIPC-insulinin micesuggested that ¹³¹I could clear rapidly from the blood,mainly excreted by kidney. However, ¹³¹I uptake of mice with¹³¹I-SIPC-insulin in some key organs, especially in thyroid and stomach, were much less (150 or 30 times) than that with the direct labeled insulin (¹³¹I-insulin). Additionally, it was noted that ¹³¹I-SIPC-insulin hasmuch betterinvivo stability than¹³¹I-insulin.</p> </p>     

Rapid radiochemical analysis of 131I in environmental samples using a well-type Ge-detector

Large-scale production of ¹³¹I in a nuclear reactor, the gaseous nature of ¹³¹I, and its selective uptake by the human thyroid gland, make this radioisotope a health hazard in the event of a nuclear accident. The maximum concentration of ¹³¹I in drinking water has been set at 1 pCi/l. Human ingestion of ¹³¹I through the grass-cow-milk pathway makes milk an environmentally significant matrix to be monitored for. In this paper, we report a simple and a rapid radiochemical procedure for the analysis of ¹³¹I in water and milk samples. A quick single-step separation on anion-exchange resin concentrates radioiodine from large sample volumes. The resin is then directly counted in the cavity of a low-background well-type HPGe detector that has high counting efficiency for X-rays and low-energy -radiation. Chemical recovery is evaluated from the intensity of the 29.6 keV X-rays of the ¹²⁹I spike, and ¹³¹I is assayed through the intensity of its 364.5 keV g-peak. The method's minimum detection limit is 0.5 pCi ¹³¹I based on a 1 liter sample and a 200-minute count.     

Reuse of decayed tellurium dioxide target for production of iodine-131

Iodine-131 was generated by irradiation of natural tellurium dioxide in a nuclear reactor. After irradiation the tellurium dioxide was transferred to hot cell and heated in a quartz furnace at ~700 °C. The Iodine-131 was distilled and collected in carbonate/bicarbonate buffer and used for thyroid cancer patients. The tellurium dioxide used was >99 % pure. During nuclear reaction nanogram tellurium was consumed to produce ¹³¹I, although significant loss of target material may occur in heating process. In dry distillation technique no chemical was added to irradiated target material. After ¹³¹I separation tellurium dioxide was decayed for 8 years in radioactive waste management facility. The decayed TeO₂ was recovered, melted and crushed for desired mesh size. The TeO₂ was sealed in Al capsule for re-irradiation purposes. The separation of ¹³¹I was carried out via dry distillation. The purity and yield of ¹³¹I separated from both of the irradiated new and irradiated re-used tellurium dioxide targets were comparable.     

Activation analytical determination of129I in bovine thyroid glands

The continued erection of nuclear installations which is expected in the future involves a greater production of long-lived fission products, which result in a concentration increase in the biosphere, the hydrosphere and the atmosphere. In the frame of a broad survey program, a routine method has been developed with the help of the European Communities to investigate the¹²⁹I content of thyroid glands of cows. It is the purpose of this project to determine the present concentration situation of this nuclide, which in the Federal Republic of Germany mainly concerns the North German low plains. Between autumn '76 and summer '77 18 cows have been investigated with respect to¹²⁹I, and thyroid glands have been taken at different times in November '76 and August '77. Without exception, the animals were 13-month old bulls, part of which has pastured, while the other part has been fed. The detection limit of the method is 20fCi of¹²⁹I.     

Graves病患者经131I治疗后血浆和红细胞锌含量的变化及其临床意义

为研究Graves病(GD)患者经^131I治疗后血浆和红细胞锌(Zn)含量的变化及其临床意义，采用原子吸收分光光谱法(AAS)和放射免疫分析法(Rn)分别检测了40例GD患者、20例经^131I治疗后甲状腺功能恢复至正常水平GD患者与30名健康人血浆和红细胞Zn的含量以及血浆甲状腺激素水平。结果表明，GD组红细胞Zn含量明显低于对照组(P＜0．01)；血浆Zn含量虽略低于对照组，但无统计学意义(P＜0．05)；且Zn与FT4呈明显负相关(P＜0．01)、与TSH呈正相关(P＜0．05)。GD治疗缓解组红细胞Zn明显高于治疗前(P＜0．01)，血浆Zn明显低于治疗前(P＜0．05)；红细胞Zn检测GD的敏感性与特异性分别为95．0％与96．7％。提示GD患者存在红细胞Zn含量改变，甲状腺激素可能干扰红细胞Zn的代谢，同时测定红细胞Zn可作为GD的临床诊断、治疗以及疾病转归的参考指标。     

Variation of counting efficiency in determination of 131I activity in the thyroid gland as a result of its position relative to the detector

The appropriate determination of the ¹³¹I which was absorbed into the human body, especially by thyroid, depends not only on individual features of each measurement subjects but also on reproducibility of their position or the thyroid’s position in the human neck. Possible uncertainties caused by changes of the thyroid position relative to detector were studied in a series of measurements. The research has shown that the dispersion of the results can reach up even to the level of 50 %.     

The use of radioiodine in the management of the differentiated tyroid cancer

The use of radioactive iodine (¹³¹I) has substantially improved the prognosis of the differentiated thyroid cancer (DTC); however, its use can be effective only if it is planned with a precise strategy. A “radical” protocol of treatment is described, involving surgical “near total” thyroidectomy, followed by an “ablative” treatment with radioiodine. A total body (TB) scan is performed just after the treatment and, if it is negative, is repeated later with a tracer dose, in order to detect functioning distant metastases, if any, suitable for¹³¹I therapy. Out of a series of 202 patients affected by DTC, several cases (from 9 to 37%, depending on initial stage), who were apparently free of metastases on clinical and radiological basis, resulted positive for functioning metastases not known before, involving lungs, or lymph-nodes, or bones. Patients whose metastases had been discovered only by scan were successfully cured in larger numbers and with lesser amount of radioiodine, compared with others whose metastases were already known on clinical or radiological grounds. Side effects of the treatment were minimal, and not disproportionate to the disease. Patients administered with radioiodine in therapeutic dosage were admitted to the hospital in a special restricted area. Waste handling facilities are described.     

Production of 131I capsules: Quality control of the different stages from the physician's order to patient's administration

The Radiochemistry Department of Rotem Industries produces ¹³¹I hard gelatin capsules for the treatment and diagnosis of different thyroid disorders. Each capsule is designated for a specified patient according to the physician's decision that is based on the patient's morbid status. GMP (Good Manufacturing Practices) requirements have been implemented throughout the production process resulting in the accreditation by the Israeli Ministry of Health. A computerized system has been developed and is used as a QC tool throughout the process of ¹³¹I capsule production. The request by the physician for capsules of various activities are introduced into the system and the process from production through packaging and external radiation monitoring is computer-controlled. The system prevents the possibility of double orders, out of specification production and enables documentation of data regardless of production date.     

生产99Mo、131I和89Sr医用同位素的水溶液堆

99Mo1、31I和89Sr等医用同位素对人类健康和医学的发展具有非常重要的作用。与靶辐照反应堆相比,用水溶液堆生产99Mo1、31I和89Sr具有安全性好,结构简单,经济价值高,无靶件制备、溶解工艺,产生废物少等优点,用水溶液堆生产医用同位素具有很好的发展前景。由于多堆芯水溶液堆、高功率水溶液堆均能显著提高产率,低富集度235U水溶液堆符合核不扩散条约中对235U浓缩度的要求,因此这三种堆是水溶液堆未来的发展方向。