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The radiation exposure of thyroid glands due to 131 I as a consequence of the Chernobyl accident was investigated retrospectively based on 129 I and 137 Cs inventories in soils in Northern Ukraine. To this end, soil samples from 60 settlements were investigated for 129 I, 127 I, and 137 Cs by AMS, ICP-MS and gamma-spectrometry, respectively. Sampling was performed between 2004 und 2007. In those parts of Northern Ukraine investigated here the 129 I and 137 Cs inventories are well correlated, the variability of the individual 129 I/ 137 Cs ratios being, however, high. Both the 129 I and 137 Cs inventories in the individual 5 samples for each settlement allowed estimating the uncertainties of the inventories due to the variability of the radionuclide deposition and consequently of the retrospective dosimetry. Thyroid equivalent doses were calculated from the 129 I and the 137 Cs inventories using aggregated dose coefficients for 5-year old and 10-year-old children as well as for adults. The highest thyroid equivalent doses (calculated from 129 I inventories) were calculated for Wladimirowka with 30 Gy for 5-years-old children and 7 Gy for adults. In 35 settlements of contamination zone II the geometric mean of the thyroid equivalent doses was 2.0 Gy for 5-years-old children with a geometric standard deviation (GSD) of 3.0. For adults the geometric mean was 0.47 Gy also with a GSD of 3.0. In more than 25 settlements of contamination zone III the geometric means were 0.82 Gy for 5-years old children with a GSD of 1.8 and 0.21 Gy for adults (GSD 1.8). For 45 settlements, the results of the retrospective dosimetry could be compared with thyroid equivalent doses calculated using time-integrated 131 I activities of thyroids which were measured in 1986. Thus, a critical evaluation of the results was possible which demonstrated the general feasibility of the method, but also the associated uncertainties and limitations. [ABSTRACT FROM AUTHOR]

We present a rare case with inguinal iodine-131 (I-131) uptake on whole body scan. The patient was suffering from a painful right inguinal mass during menstrual period, which was later sonographically and histopathologically confirmed to be an inguinal focus of endometriosis. Endometriosis is a previously reported site of radioiodine uptake and detection of radioiodine uptake in the inguinal region has also been described. Nevertheless, to the best of our knowledge, this is the first case report of I-131 uptake in an inguinal endometriosis focus. History and physical examination of the patient are both very important in identifying the etiology of the ectopic uptake sites on I-131 whole body scan, and inguinal endometriosis should be kept in mind while reporting inguinal radioiodine uptake on I-131 whole body scan. [ABSTRACT FROM AUTHOR]

Brain cancer is a challenging disease to treat using conventional approaches. The present investigation aimed to develop a radiopharmaceutical targeting brain cancer based on natural isovanillin. Different parameters were optimized, resulting in high radiolabeling efficiency (97.3 ± 1.2%) and good stability (<48 h). The tracer was formulated for intranasal delivery in a chitosan nanoparticles system with a mean particle size of 141 ± 2 nm, a polydispersity index of 0.23 ± 0.02, and a zeta potential of −17.4 ± 0.3 mV to enhance nasal uptake and surmount the blood-brain barrier. The system was characterized and assessed in-vitro for suitability and specificity and evaluated in-vivo in normal and tumorized mice. The biodistribution profile in brain tumor showed 20.5 ± 0.4 %ID/g localization and cancer cell targeting within 60 min. Improvement in brain tumor uptake resulted from both the nanoformulation and nasal administration of iodoisovanillin. Overall, the reported results encourage the potential use of the nanoformulated labeled compound as an anticancer agent. • [131I]-isovanillin was obtained at high radiochemical yield (∼97.3%), and good stability (<48h). • [131I]-Isovanillin-chitosan nanoparticles system was prepared to enhance nasal uptake and surmount the blood-brain barrier. • The labeled nanoparticles showed a good specific cytotoxic effect versus the human U-25 cell line. • The biodistribution profile of labeled nanoparticles showed ∼20.5% localization and preferential brain tumor targeting. [ABSTRACT FROM AUTHOR]

Mixer-setters units are widely used in uranium purification processes. For efficient operations of mixer-settler units, it is essential to measure the hydrodynamics parameters of the different phases involved. The residence time distribution (RTD) measurement is commonly used method to estimate the hydrodynamics parameters of process reactors. In the present study, RTD of the aqueous phase was measured in different stages mixer-settler unit (mixers, settlers and mixer-settler units) used for stripping operation using Iodine-131 as a radiotracer. For the RTD measurements, radiotracer was injected as an impulse in aqueous phase feed line and its movement was monitored at different locations in the stripping unit using NaI(Tl) detectors. The mean residence times (MRTs) of the aqueous phase were estimated from measured RTD curves. For quantification of the degree of mixing, suitable flow models were proposed based on design and nature of the measured RTD curves and subsequently used for simulation. Based on the results of the RTD study, the mixing of aqueous phase was characterized and design of the stripping unit and its sub-units were validated. The optimum conditions were identified for efficient for the operation of the stripping unit. • The aqueous phase RTD in stripper unit and its sub-units was measured. • The MRT of the aqueous was estimated at different operating conditions. • Different flow models were used to quantify degree of mixing of aqueous phase. • The operating conditions of the stripping unit were optimized. [ABSTRACT FROM AUTHOR]

The diagnosis of intermittent claudication (IC) is challenging. Imaging with radiopharmaceuticals provides a new method for detecting acute IC. Pentoxifylline improves blood flow to ischemic tissues via increasing erythrocyte elasticity and inhibiting platelet aggregation. Pentoxifylline was radio-iodinated with radioiodine-131 (131I) through a direct electrophilic substitution reaction. Furthermore, various factors that might influence the radiolabeling strategy were investigated. The radiochemical yield of [131I]iodopentoxiphyline was evaluated by using paper chromatography and HPLC methods. The biodistribution pattern of [131I]iodopentoxiphyline was studied, where Swiss albino mice was used as a model of acute limb ischemia-reperfusion. The maximum radiochemical yield of pentoxifylline was found to be 94.11 ± 2.35%. The biodistribution findings revealed that [131I]iodopentoxiphyline was significantly deposited at the ischemic site (left hind limbs), with encouraging target/non-target (T/NT) ratios. At 0.25 and 1 h post injection, the uptake of [131I]iodo-pentoxifylline was 5.30 ± 0.30 and 9.98 ± 1.12%, respectively. Also, the maximum T/NT ratio for [131I]iodo-pentoxifylline (9.45 ± 0.26) was obtained at 0.25 h post injection. Due to safety and selectivity, [131I]iodo-pentoxifylline may be a good prospective diagnostic tool for early identification of IC. Moreover, the outcome of this study can be expected to apply to I-123 as well. • Pentoxifylline radiolabeled with iodine-131. • Various factors affecting radiochemical yield percentage were studied. • In vivo biodistribution pattern of [131I]iodopentoxiphyline was studied. • [131I]iodopentoxiphyline showed a marked accumulation at the ischemic site. [ABSTRACT FROM AUTHOR]

Anti-miRNA oligonucleotide (AMO) has been used most widely to inhibit miRNA for loss-of-function studies and function as therapeutic agents. Iodine-131 (131I) radiolabeled AMO may have multiple functions for specific imaging, genetic inhibition, and radiotherapy. This study is to prepare a radioiodinated anti-miRNA-21 AMO by one-step synthesis for preliminary imaging in tumor xenografts and in vitro radiotherapy. A tyrosine was conjugated at the 3' end of AMO via a C6 linker for labeling with 131I. After the molecular mass of AMO was confirmed by mass spectrometry, AMO was labeled with 131I by the chloramine-T method with high labeling yield (95.5% ± 3.1%). By gel electrophoresis, the radioactive distribution of 131I-AMO was located exactly where was AMO, verifying the successful radiolabeling. 131I-AMO presented high stability during 24 h of incubation in fresh human serum. The cellular uptake of 131I or FAM-labeled AMO in DU145 was significantly higher than that in PC-3 cells. After i.v. administration in mice, single-photon emission tomography (SPECT) imaging showed that increased 131I-AMO was found in DU145 tumor from 4 h to 24 h gradually. H&E staining of major organs validated the biocompatibility of 131I-AMO in vivo. Furthermore, the ability of 131I-AMO to inhibit cell growth is superior to that of 131I, along with stronger apoptosis in DU145 cells than in PC-3 cells. Therefore, AMO can be labeled with 131I via one-step synthesis after tyrosine conjugation in this study. Its high labeling yield, stability, inhibitory effect, and tumor distribution provide the potential value in the targeted theranostic role. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Aggressive thyroid carcinoma (ATC) usually loses radioiodine avidity to iodine-131 ( 131 I) due to the downregulation of sodium/iodide symporter (NIS). The expression of thyroid stimulating hormone receptor (TSHR) is more persistent than NIS and the administration of recombinant human thyroid stimulating hormone (rhTSH) promotes de novo NIS synthesis. Hence, exploring methods integrating 131 I with rhTSH might be a feasible therapeutic strategy for selective delivery of 131 I into thyroid cancer to fortify the effect of radioiodine ablation., Methods: The 131 I, poly (lactic-co-glycolic acid) (PLGA) and rhTSH were used to synthesize of the 131 I-PLGA-rhTSH nanoparticles. The characteristics of the 131 I-PLGA-rhTSH nanoparticles was determined using a light microscopy, scanning electron microscopy (SEM), autoradiography and immunofluorescence (IF) staining. The diameter of the 131 I-PLGA-rhTSH nanoparticles was measured with a Mastersizer 3000, and the encapsulation efficiency (EF) of 131 I in 131 I-PLGA-rhTSH nanoparticles and the radioactivity of a single nanoparticle were determined. Then, the mouse tumor xenograft model was established, and the biodistribution and effect of 131 I-PLGA-rhTSH nanoparticles on apoptosis of thyroid cance cells were investigated in vivo. Thereafter, the role of 131 I-PLGA-rhTSH nanoparticles in cell viability using cell counting kit-8 and lactate dehydrogenase (LDH) release assays. Subsequently, the underlying mechanism of 131 I-PLGA-rhTSH nanoparticles in reducing cell viability was assessed using immunostaining, boyden invasion assays and phalloidin staining., Results: Our results showed that the method of developing nanoparticles-encapsulated 131 I using poly (lactic-co-glycolic acid) (PLGA) and modified with rhTSH ( 131 I-PLGA-rhTSH), was a feasible avenue for the integration of 131 I and rhTSH. Meanwhile, the encapsulation efficiency (EF) of 131 I-PLGA-rhTSH nanoparticles was approximately 60%, and the radioactivity of a single nanoparticle was about 1.1×10-2 Bq. Meanwhile, the 131 I-PLGA-rhTSH nanoparticles were selectively delivered into, gradually enriched and slowly downregulated in xenograft tumor after the administration of 131 I-PLGA-rhTSH nanoparticles through tail vein in mouse tumor xenograft model. Thereafter, the tumor weight was significantly reduced after the administration of 131 I-PLGA-rhTSH nanoparticles. Subsequently, the application of 131 I-PLGA-rhTSH nanoparticles facilitated apoptosis and attenuated immobilization via inhibiting F-actin assembling of FTC-133 cells., Conclusion: The present study develops a suitable approach integrating 131 I and rhTSH, and this strategy is a feasible regimen enhancing the effect of radioiodine ablation for the treatment of thyroid cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Fan, Xiong, Wang, Chen, Fang, Huang and Yuan.)

This study focuses on iodine-131 detected in milk samples from the Dairy Science Unit at Cal Poly, San Luis Obispo, California following events at the Fukushima Dai-ichi Nuclear Power Plant in March of 2011. The milk samples, collected between March 21 and April 11, 2011, were part of the Diablo Canyon Nuclear Power Plant Radiological Environmental Monitoring Program. A correlation is made between the integrated activity of iodine-131 found in milk and the integrated activities of iodine-131 of rainwater, vegetation and air samples that were collected from March 19 to April 18, 2011. A comparison is then made to previous studies conducted on dairy cattle that were administered controlled amounts of iodine-131 through ingestion. The comparison shows good agreement to the model which states that generally 1 percent of the activity of iodine-131 ingested by dairy cattle will be detected in harvested milk. Considering the environmental factors and the uncertainties involved, these data and calculated results derived from a real world situation provide an excellent application and confirmation of studies done under controlled settings. [ABSTRACT FROM AUTHOR]

The sorption of CHI and I from a water vapor-gas medium onto various grades of activated carbon was studied. All the sorbents tested exhibit high ability to take up I. The I uptake exceeds 99.95% at 60°C and contact time of the gas phase with the sorbent τ = 0.5-0.7 s. The ability of the sorbents based on activated carbon to take up CHI strongly depends on the sorbent particle size. High ability to take up CHI from a water vapor-air flow is preserved only for cylindrical particles 1.0 mm in diameter and 1.0-2.0 mm long. Activated anthracite, like activated carbon with cylindrical particles 3.5 mm in diameter and 3.0-9.0 mm long, exhibits low performance in CHI uptake. The degree of localization of CHI does not exceed 40% at 60°C and τ = 0.5-0.7 s. [ABSTRACT FROM AUTHOR]

131 I is widely used in nuclear medicine for diagnostic and therapy of thyroid diseases. Depending of workplace safety conditions, routine handling of this radionuclide may result in a significant risk of exposure of the workers subject to chronic intake by inhalation of aerosols. A previous study including in vivo and in vitro measurements performed recently among nuclear medicine personnel in Brazil showed the occurrence of 131 I incorporation by workers involved in the handling of solutions used for radioiodine therapy. The present work describes the development, optimization and application of a methodology to collect and analyze aerosol samples aiming to assess internal doses based on the activity of 131 I present in a radiopharmacy laboratory. Portable samplers were positioned at one meter distant from the place where non-sealed liquid sources of 131 I are handled. Samples were collected over 1 h using high-efficiency filters containing activated carbon and analyzed by gamma spectrometry with a high-purity germanium detection system. Results have shown that, although a fume hood is available in the laboratory, 131 I in the form of vapor was detected in the workplace. The average activity concentration was found to be of 7.4 Bq/m 3 . This value is about three orders of magnitude below the Derived Air Concentration (DAC) of 8.4 kBq/m 3 . Assuming that the worker is exposed by inhalation of iodine vapor during 1 h, 131 I concentration detected corresponds to an intake of 3.6 Bq which results in a committed effective dose of 7.13×10 −5 mSv. These results show that the radiopharmacy laboratory evaluated is safe in terms of internal exposure of the workers. However it is recommended that the presence of 131 I should be periodically re-assessed since it may increase individual effective doses. It should also be pointed out that the results obtained so far reflect a survey carried out in a specific workplace. Thus, it is suggested to apply the methodology developed in this work to other nuclear medicine services where significant activities of 131 I are routinely handled as an effective means to optimize individual exposures and improve occupational radiation protection safety. [ABSTRACT FROM AUTHOR]

Iodine-131 is known to destroy residual thyroid tissue following surgical resection of differentiated thyroid carcinoma and is widely used to treat hyperthyroidism. However, the mechanism by which iodine-131 induces apoptosis and cell cycle arrest in the human thyrocyte cell line, Htori-3, remains to be elucidated. In the present study, the cytotoxic effect of iodine-131 on the HTori-3 cell line and the underlying mechanism of iodine-131-induced cell apoptosis were investigated. Cell viability was analyzed using an MTT assay, while cell apoptosis and cell cycle arrest were determined using flow cytometry. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analyses were performed to determine the changes in the expression levels of p53, B-cell lymphoma 2 (Bcl-2), Fas and growth arrest and DNA damage-inducible 45 (GADD45), following iodine-131 treatment. The results demonstrated that iodine-131 may inhibit HTori-3 cell growth via cell apoptosis and G2/M phase arrest in a time- and dose-dependent manner. The iodine-131 dose required for 50% growth inhibition of HTori-3 cell viability 48 h after treatment was 27.75±2.22 MBq/ml. Upregulation of Fas and downregulation of Bcl-2 expression levels were observed following iodine-131 treatment. The results of RT-qPCR revealed an increase in the GADD45 mRNA expression following HTori-3 cell exposure to iodine-131. Notably, the mRNA and protein expression levels of p53 were not altered following iodine-131 treatment. In conclusion, iodine-131 may induce apoptosis in HTori-3 cells by downregulating the expression of Bcl-2 and upregulating the expression of Fas. In addition, iodine-131 may upregulate GADD45 mRNA expression in HTori-3 cells, resulting in G2/M phase arrest in a p53-independent pathway. [ABSTRACT FROM AUTHOR]

Résumé Le traitement ablatif à l’iode 131 du cancer de la thyroïde chez l’hémodialysé chronique représente un réel problème puisque la principale voie d’élimination de l’iode radioactif est urinaire. De plus, il n’existe aucune recommandation concernant la gestion de ce traitement chez l’hémodialysé. Nous rapportons dans cet article notre expérience de gestion de ce traitement chez un patient âgé de 38 ans, insuffisant rénal chronique au stade terminal, en hémodialyse chronique, et chez qui avait été portée l’indication d’un traitement à l’iode 131 pour un carcinome papillaire de la thyroïde à haut risque évolutif. Après discussion multidisciplinaire (néphrologues, spécialistes en médecine nucléaire et radioprotection), il a été décidé de traiter le patient par dialyse péritonéale continue ambulatoire (DPCA) pour gérer le traitement ablatif à l’iode 131. Étant donné l’élimination faible mais continue de l’iode en DPCA, le patient a reçu une dose réduite d’iode 131 de 1850 MBq, soit 30 % de la dose habituelle donnée chez un sujet à fonction rénale normale. L’hospitalisation a duré quatre jours dans le service de médecine nucléaire, et le débit émis par le patient à sa sortie était de 2,5 μSv/h à un mètre. En conclusion, la DPCA en relais de l’hémodialyse est une technique d’épuration extra-rénale qui peut être proposée pour minimiser l’exposition à la radioactivité du patient, de sa famille et du personnel médical. Iodine-131 ablation therapy for thyroid cancer in the patient on chronic hemodialysis represents a real problem since the main route of elimination of radioiodine is urinary. There is no recommendation on the management of this treatment in the patient on hemodialysis. We report our experience of management of this treatment in a patient aged 38 years, undergoing hemodialysis for chronic renal failure, and who have been indicated the treatment with iodine-131 for papillary thyroid carcinoma high risk. After multidisciplinary discussions (nephrologists and specialists in nuclear medicine and radiation safety), it has been decided to treat the patient with continuous ambulatory peritoneal dialysis therapy (CAPD). Because of the low but continuous elimination of iodine in the case of CAPD, the patient received a reduced ablative 131 I dose of 1850 MBq, which is 30% of the usual dose delivered in subjects with normal renal function. The patient was hospitalized for four days in nuclear medicine unit and the 131 I radioactivity emitted from him was 2.5 μSv/h at one meter at his hospital discharge. In conclusion, CAPD in relay of hemodialysis is a technique of renal replacement therapy that can be suggested to minimize exposure to radioactivity to the patient, his family and the medical staff. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to investigate the clinical significance of diffuse hepatic uptake on post-therapeutic early and delayed I scan in patients with differentiated thyroid cancer (DTC). Methods: We retrospectively analyzed 219 DTC patients who underwent high-dose I treatment and subsequent post-therapeutic dual I scan. Both early (third day after I treatment) and delayed (5-6th day after I treatment) I scan images were visually assessed and diffuse hepatic uptake was scored using a 4-point grading system depending on intensity. Results: On early I scan, 73 patients (33.4 %) showed diffuse hepatic uptake, while 191 patients (87.2 %) patients showed diffuse hepatic uptake on delayed scan ( p < 0.0001). The serum levels of ALT in patients with diffuse hepatic uptake on early scan were higher than those without diffuse hepatic uptake on early scan ( p = 0.03 for ALT and p = 0.08 for AST). The serum levels of ALT and AST trended with the grade of hepatic uptake on delayed scan ( p = 0.03 for ALT and p = 0.05 for AST). Diffuse hepatic uptake on early or delayed scan showed no significant relationship in the presence of thyroid remnants, metastatic DTC lesions, tumor recurrence during follow-up, and the serum thyroglobulin level ( p > 0.05). On logistic regression analysis, both serum ALT ( p = 0.01) and AST ( p = 0.04) levels were significant predictive factors for diffuse hepatic uptake on early scan, while only serum ALT ( p = 0.01) level was significant predictive factor for diffuse hepatic uptake on delayed scan. Conclusions: The frequency of diffuse hepatic uptake on the delayed scan was significantly higher than the early scan. Diffuse hepatic uptake on early post-therapeutic scan and the intensity of diffuse hepatic uptake on delayed scan showed significant correlation with the serum levels of hepatic enzymes, but no significant association in the presence of thyroid remnants, metastatic DTC lesions, and tumor recurrence during follow-up. The timing and intensity of diffuse hepatic uptake on post-therapeutic scan may be related with factors such as hepatic function other than the thyroid tissue or DTC. [ABSTRACT FROM AUTHOR]

Radioactive iodine (131I) is a known radionuclide which is used both for diagnostic and therapeutic purposes in the treatment of hyperthyroidism and thyroid cancer. Montelukast sodium (Cysteinyl leukotriene receptor-1 antagonist) is also a well-known antioxidant drug. This study aimed to evaluate the histopathological changes in rat livers at the third month following 131I treatment and the radioprotective effect of Montelukast sodium (ML) against I-related liver damage. Thirty female Wistar Albino rats were randomly divided into three groups as control group (n=10), untreated rats; second (RAI) group (n=10), oral radioiodine (111 MBq) administrated rats, and third (ML) group (n=10), oral radioiodine and ML administrated rats. In the third group, ML administration was started 3 days before and ended 10 days after RAI administration. In the third month of radioiodine (RAI) administration, the animals were decapitated and the livers were removed for histopathological examination. The histopathologic data were evaluated comparatively by using Mann Whitney U and Fisher's Exact Tests Differences were determined in all the parameters in terms of intensity between the control and 131I groups, which showed the harmful effects of 131I. In the comparison of the 131I and ML groups, hyperemia was determined respectively 80% to 40%, the presence of inflammatory cells 70% to 60% and capsule thickening 70% to 40%. Montelukast sodium was observed to have a protective effect especially on hyperemia and capsule thickening. According to the study results, radioactive iodine (131I) treatment seems to cause morphological damage to the rat liver, and Montelukast sodium effectively protects the liver against damage. [ABSTRACT FROM AUTHOR]

Thermal decomposition of a volatile organic compound of radioactive iodine, CHI, in a gas flow in the presence of various modifications of granulated materials based on KSKG silica gel impregnated with nanometric particles of Ni compounds was studied. The degree of CHI decomposition as high as 97-99% is reached at 450 ± 20°C in the presence of granules of KSKG-based composite containing 8 wt % Ni in the form of NiO. The degree of CHI decomposition depends on the contact time of the gas phase and composite, temperature of the composite, and amount of CHI introduced into the gas flow. [ABSTRACT FROM AUTHOR]

The present article describes the development of an indigenous technology for large scale production of I based on the neutron irradiation of TeO target followed by the separation of I using dry distillation technique. In one batch, typically 180 g of natural TeO was irradiated for a period of 21 days in a thermal neutron flux of ~5 × 10 n cm s, which after chemical processing provided ~1.85 TBq (50 Ci) of I. The suitability of I for medical application was evaluated scrupulously in order to ensure compliance with stipulated pharmacopoeia requirement. [ABSTRACT FROM AUTHOR]

This study develops and compares different, increasingly detailed anatomical phantoms for rainbow trout ( Oncorhynchus mykiss) for the purpose of estimating organ absorbed radiation dose and dose rates from 131 I uptake in multiple organs. The models considered are: a simplistic geometry considering a single organ, a more specific geometry employing additional organs with anatomically relevant size and location, and voxel reconstruction of internal anatomy obtained from CT imaging (referred to as CSUTROUT). Dose Conversion Factors (DCFs) for whole body as well as selected organs of O. mykiss were computed using Monte Carlo modeling, and combined with estimated activity concentrations, to approximate dose rates and ultimately determine cumulative radiation dose (μGy) to selected organs after several half-lives of 131 I. The different computational models provided similar results, especially for source organs (less than 30% difference between estimated doses), and whole body DCFs for each model (∼3 × 10 −3 μGy d −1 per Bq kg −1 ) were comparable to DCFs listed in ICRP 108 for 131 I. The main benefit provided by the computational models developed here is the ability to accurately determine organ dose. A conservative mass-ratio approach may provide reasonable results for sufficiently large organs, but is only applicable to individual source organs. Although CSUTROUT is the more anatomically realistic phantom, it required much more resource dedication to develop and is less flexible than the stylized phantom for similar results. There may be instances where a detailed phantom such as CSUTROUT is appropriate, but generally the stylized phantom appears to be the best choice for an ideal balance between accuracy and resource requirements. [ABSTRACT FROM AUTHOR]

Objective: to study relationship between the focal adsorbed doses (FAD) in the residual thyroid tissue (RTT) atradioiodine therapy (RIT) in patients with differentiated thyroid cancer (DTC) and efficacy of radioablation (RA)., Materials and Methods: FAD in RTT in 221 patients aged 25-74 years were analyzed. Scintigraphic investigations were executed using gamma-camera «МВ 9200» and single photon emission tomograph «Е. САМ 180». FAD in RTT were determined according to recommendation of the Committee on Medical Internal Radiation Dose., Results: Mean FAD in RTT was consisted (125.9 ± 8.6) Gy with range 1.8-1373.4 Gy. Positive effect after first course of RIT was in 77.4 % of patients complete RA of 78 % of RTT was achieved. Mean FAD in cases with complete RA was (147.0 ± 13.3) Gy with range 1.8-1373.4 Gy. Efficacy of RIT constantly increased from 68.2 to 93.7 % with increasing mean FAD from 30 to 370 Gy. Feather enlarging of FAD did not lead to any significant increasing of efficacy of RIT:enlarging mean FAD from 370 to 776 Gy increased efficacy of RA on 0.4 % only. Repeated RIT decreased FAD in RTTafter each course. Using regression analysis was established type of relationship between efficacy of RA and FAD in RTT, according it efficacy of first RA consists at 40 Gy 72.8 %, 150 Gy - 84.9 %, 300 Gy - 91.2 %, 400 Gy - 93.7 %,500 Gy - 95.7 %., Conclusions: FAD in RTT at RIT differ in large range, it can be explained different anatomical and functional condition of iodine accumulate thyroid tissue after surgical treatment and its radioresistance. Efficacy of RA increases with enlarging of FAD, this relationship is nonlinear. Efficacy of RA has the upper dose threshold in range 350-400 Gy. The frequency of thyroid tissue with high radioresistance is approximately 6 %., (D. О. Dzhuzha.)

[Display omitted] • Silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). • The synthesized nanocomposite was radiolabelled with iodine-131 radionuclide. • The synergistic MM-proliferation inhibition efficacy of the radionanocomposite (131I-Isatuximab/AgNPs) was explored in-vitro. • The proliferation, apoptosis and caspase 3/7 of myeloma cells were investigated while using 131I-Isatuximab/AgNPs. • The results expressed 131I-Isatuximab/AgNPs as a potential new anti-MM agent. The goal of this article was to develop a new therapeutic strategy based on nanotechnology for multiple myeloma (MM) treatment which shows a synergism of different mechanisms. In this concern, 12.9 nm-sized silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). Furthermore, the synthesized nanocomposite was radiolabelled with iodine-131 radionuclide and yielded 95.5 ± 1.5%. Then, the synergistic MM-proliferation inhibition efficacy of the radionanocomposite (131I-Isatuximab/AgNPs) was explored in-vitro in comparison to each single agent. The MTT investigation showed that the antiproliferation effect of 131I-Isatuximab/AgNPs increased by more than 1.5 fold if compared with Isatuximab, AgNPs, Isatuximab/AgNPs or 131I-Isatuximab. Additionally, 131I-Isatuximab/AgNPs exhibited an apoptotic effect on MM cells which was more than that of Isatuximab, AgNPs, Isatuximab/AgNPs or 131I-Isatuximab by 2, 1.8, 1.7 and 1.5 folds, respectively. In conclusion, the results expressed 131I-Isatuximab/AgNPs as a potential new anti-MM agent. [ABSTRACT FROM AUTHOR]

Differentiated thyroid cancer is the second-most frequent tumor among those tumors diagnosed during pregnancy after breast cancer; it also is the most common endocrine malignancy. Pregnancy-associated cancer was defined as a malignancy detected during pregnancy or within 2 years of delivery, but most of the patients with pregnancy-associated cancer were recognized in the postpartum period. The best time for surgery is unclear. Its management is a challenge for both doctors and patients. Enlargement of the thyroid gland in pregnancy is usually a physiological change related to pregnancy, but even if it is rare, it can be due to thyroid malignancy. We report a case of 31-year-old female diagnosed with thyroid papillary cancer during pregnancy with no symptoms except for a lump on her neck. For this reason, the examination of the thyroid gland and the examination of neck lymph nodes should be routinely performed on all pregnant women. [ABSTRACT FROM AUTHOR]

129I is commonly either the top or among the top risk drivers, along with99Tc, at radiological waste disposal sites and contaminated groundwater sites where nuclear material fabrication or reprocessing has occurred. The risk stems largely from129I having a high toxicity, a high bioaccumulation factor (90% of all the body's iodine concentrates in the thyroid), a high inventory at source terms (due to its high fission yield), an extremely long half-life (16M years), and rapid mobility in the subsurface environment. Another important reason that129I is a key risk driver is that there is uncertainty regarding its biogeochemical fate and transport in the environment. We typically can define129I mass balance and flux at sites, but cannot predict accurately its response to changes in the environment. As a consequence of some of these characteristics,129I has a very low drinking water standard, which is set at 1 pCi/L, the lowest of all radionuclides in the Federal Register. Recently, significant advancements have been made in detecting iodine species at ambient groundwater concentrations, defining the nature of the organic matter and iodine bond, and quantifying the role of naturally occurring sediment microbes to promote iodine oxidation and reduction. These recent studies have led to a more mechanistic understanding of radioiodine biogeochemistry. The objective of this review is to describe these advances and to provide a state of the science of radioiodine biogeochemistry relevant to its fate and transport in the terrestrial environment and provide information useful for making decisions regarding the stewardship and remediation of129I contaminated sites. As part of this review, knowledge gaps were identified that would significantly advance the goals of basic and applied research programs for accelerating129I environmental remediation and reducing uncertainty associated with disposal of129I waste. Together the information gained from addressing these knowledge gaps will not alter the observation that129I is primarily mobile, but it will likely permit demonstration that the entire129I pool in the source term is not moving at the same rate and some may be tightly bound to the sediment, thereby smearing the modeled129I peak and reducing maximum calculated risk. [ABSTRACT FROM AUTHOR]

Objective: Non-thyroidal complication of high-dose radioiodine therapy for thyroid carcinoma might cause salivary and lacrimal gland dysfunction, which may be transient or permanent in a dose-dependent manner. However, radiation retinopathy complicating 131I therapy, has not been previously well characterized. The aim of this study was to evaluate the extent of retinal damage among patients who had received high doses of radioiodine treatment. Methods: Forty eyes of 20 patients (3 male, 17 female) who received 250-1000 mCi during 131I therapy and on ophthalmological follow up for a year after the last treatment were included in the study. Mean age of the study group was 50 years (range 25-70 years). In ophthalmologic examination, visual acuity was measured in order to determine visual loss. Intraocular pressure was measured in all the patients. Then lens examination was carried out with slit lamp biomicroscopy in order to investigate cataract or partial lens opacities. Fundus observation was carried out through the dilated pupil with slit lamp biomicroscopy using 90 D noncontact lens. Result: The best corrected visual aquity with Snellen chart was found as 1.0 in 36 eyes (90%) and between 0.6 and 0.9 (10%) in 4 eyes (10%). At the biomicroscopic fundus examination, retinal hemorrhage consistent with radiation retinopathy, microaneurysm, microinfarction, edema or exudation, vitreus hemorrhage, partial or total optical disc pallor indicating papillopathy in the optic disc were not observed in any of the eyes. Conclusion: This result indicates that there is not any significant correlation between repeated high-dose radioiodine therapy and radiation retinopathy in differentiated thyroid carcinomas. Even though there is not a significant restriction in use of higher doses of radioiodine therapy in differentiated thyroid carcinoma, more extensive studies are needed in order to obtain more accurate data on possible occurrence of retinopathy. [ABSTRACT FROM AUTHOR]

We treated patients under age 50 years with iodine-131 (131I)-anti-CD45 antibody combined with fludarabine and 2 Gy total body irradiation to create an improved hematopoietic cell transplantation (HCT) strategy for advanced acute myeloid leukemia or high-risk myelodysplastic syndrome patients. Fifteen patients received 332 to 1561 mCi of 131I, delivering an average of 27 Gy to bone marrow, 84 Gy to spleen, and 21 Gy to liver. Although a maximum dose of 28 Gy was delivered to the liver, no dose-limiting toxicity was observed. Marrow doses were arbitrarily capped at 43 Gy to avoid radiation-induced stromal damage; however, no graft failure or evidence of stromal damage was observed. Twelve patients (80%) developed grade II graft-versus-host disease (GVHD), 1 patient developed grade III GVHD, and no patients developed grade IV GVHD during the first 100 days after HCT. Of the 12 patients with chronic GVHD data, 10 developed chronic GVHD, generally involving the skin and mouth. Six patients (40%) are surviving after a median of 5.0 years (range, 4.2 to 8.3 years). The estimated survival at 1 year was 73% among the 15 treated patients. Eight patients relapsed, 7 of whom subsequently died. The median time to relapse among these 8 patients was 54 days (range, 26 to 1364 days). No cases of nonrelapse mortality were observed in the first year after transplantation. However, 2 patients died in remission from complications of chronic GVHD and cardiomyopathy, at 18 months and 14 months after transplantation, respectively. This study suggests that patients may tolerate myeloablative doses >28 Gy delivered to the liver using 131I-anti-CD45 antibody in addition to standard reduced-intensity conditioning. Moreover, the arbitrary limit of 43 Gy to the marrow may be unnecessarily conservative, and continued escalation of targeted radioimmunotherapy doses may be feasible to further reduce relapse. [ABSTRACT FROM AUTHOR]

Abstract: Using anthropomorphic phantom in Geant4, determination of β- and γ-absorbed fractions and energy absorbed per event due to 131I activity in thyroid of individuals of various age groups and geometrical models, have been carried out. In the case of 131I β-particles, the values of the absorbed fraction increased from 0.88 to 0.97 with fetus age. The maximum difference in absorbed energy per decay for soft tissue and water is 7.2% for γ-rays and 0.4% for β-particles. The new mathematical MIRD embedded in Geant4 (MEG) and two-lobe ellipsoidal models developed in this work have 4.3% and 2.9% lower value of S-factor as compared with the ORNL data. [Copyright &y& Elsevier]

Sorption of CHI from a water vapor-air medium onto Fizkhimin inorganic sorbents containing Ag and nonferrous metals (Cu, Ni, Zn) was studied. Ag-free Fizkhimin inorganic sorbents exhibit poor ability to take up CHI. No more than 51% of the initial 10-mg portion of CHI is taken up by the sorbents heated to 350°C. The sorbents containing 1.4-2 wt % Ag and 5.6-8 wt % nonferrous metal (Cu, Ni, Zn) show high ability to take up CHI (>99.8% uptake), with the performance of the Ni-containing sorbents remaining very high (>99.9%) with variation of various parameters of both the sorbents and the medium. The Cu- and Zn-containing analogs do not exhibit such properties. [ABSTRACT FROM AUTHOR]

Handling a variety of unsealed sources in Nuclear Medicine has led to a significant risk of internal exposure for workers. 131I stands out among the radionuclides of frequent use due to its wide application in diagnosis and treatment of thyroid diseases. This study presents the development of in vivo bioassay techniques, in order to quantify the incorporation of 131I used in nuclear medicine. It also presents the results of research related to the internal exposure of a group of workers involved in handling therapeutic doses of 131I. The in vivo detection system was calibrated with a thyroid phantom developed at IRD (Brazil) which is also used at the UTN-IVIC (Venezuela). The workers monitored in this study presented measurable intake. Therefore, it is important to ensure future monitoring of such exposure. It also gives us the possibility of evaluating intake in cases of suspected accidents. The highest estimated effective dose was 1,28x10-5 Sv by inhalation and 1,27x10-5 Sv by ingestion. The proposed method showed enough sensitivity for its application in the assessment of the effective dose for 131I intake by workers. The minimum detectable effective dose associated with the MDA (244 to 287 Bq) is three orders of magnitude below the recording level of 1 mSv, considering a single intake by inhalation of a Type F compound of 131I in the form of vapor. [ABSTRACT FROM AUTHOR]

Objective: To characterize the epidemiological, diagnostic, and therapeutic behavior of patients with thyroid cancer (TC), with a survival greater than or equal to 20 years. Method: A retrospective and cross-sectional descriptive study was conducted in the Provincial Teaching Oncological Hospital «Maria Curie», Camagüey. The sample included 85 patients with diagnosis of TC who fulfilled the inclusion criteria. The epidemiological behavior of these patients was determined to the 20 years of their treatment. Results: The female sex predominated with 95.29%. The papillary carcinoma was the histological variety more detected. The majority were diagnosed at stage I, thyroidectomy was used as surgical technique and as adjuvant therapy the Iodine-131 and hormonotherapy in accordance. The presence of metastases was not predominant at the time of diagnosis and patient survival was about 25 to 29 years on average. Conclusions: Although thyroid cancer is a current health problem, achieve a survival of 25 to 29 years on average, when there is diagnostic specificity and therapeutic effectiveness. [ABSTRACT FROM AUTHOR]

Abstract: Iodine-131 is a major component of the atmospheric releases following reactor accidents, and the passage of 131I through food chains from grass to human thyroids has been extensively studied. By comparison, the fate and effects of 131I deposition onto lakes and other aquatic systems have been less studied. In this study we: (1) reanalyze 1960s data from experimental releases of 131I into two small lakes; (2) compare the effects of differences in lake trophic structures on the accumulation of 131I by fish; (3) relate concentrations in fish and fish tissues to that in the water column using empirically estimated uptake (L kg−1 d−1) and loss (d−1) parameters; and (4) show that the largest concentrations in the thyroids of trout (Oncorhynchus mykiss) may occur from 8 to 32 days after initial release. Iodine-131 concentration in trout thyroids at 30-days post release may be >1000 times that in the water. Estimates of cumulative radiation dose (mGy) to thyroids computed using an anatomically-appropriate model of trout thyroid structure within the Monte Carlo N-particle modeling software predicted cumulative thyroid doses that increased approximately linearly after the first 8 days and resulted in 32-day cumulative thyroid doses that ranged from 6 mGy g−1 to 18 mGy g−1 per 1 Bq mL−1 of initial 131I in the water depending upon fish size. The majority of this dose is due to beta emissions, and the dose varies with positions in the thyroid tissue. [Copyright &y& Elsevier]

Highlights: [•] p-Tertbutylcalix[4]arene nanoemulsion complexed with 99mTc, 131I &201Tl. [•] p-Tertbutylcalix[4]arene formulation shows wide spectrum decontamination. [•] The nanoemulsion is reasonably stable and skin-safe for application. [Copyright &y& Elsevier]

The removal of I and Cs from aqueous and aqueous-organic solutions with porous polyvinyl formal (PPVF) was studied. The degree of radionuclide removal from water with a PPVF sample is determined by the amount of water absorbed by the polymer and is not influenced by the concentration of salts in solution. Porous polyvinyl formal allows recovering Cs from aqueous-organic solutions with 70 to 99% efficiency. [ABSTRACT FROM AUTHOR]

Introduction: The differentiated thyroid cancers have a good prognosis unless the presence of metastasis. These distant metastases, especially in bone, are a major cause of impaired quality of life and death requiring intensive management. The aim of our work was to study the patients' data, the disease characteristics and to analyze the therapeutic management of these patients. Results: This study concerned a cohort of 21 patients treated for differentiated thyroid cancer during the period from 1995 to 2011. Eighteen of our patients were aged over 45 years. A majority of them had follicular carcinoma. Bone metastases were often multiple and located at the axial skeleton. They were associated with other types of metastases, especially lung metastasis. A majority of patients received 131I treatment, following surgery or external beam radiotherapy for a palliative purpose. Overall survival was 65% at 5 years and 49% at 10 years. A long-term survival was achieved in 10% of the patients benefiting from a multidisciplinary care adapted to each case. Conclusion: Bone metastases often have a pejorative turning in the natural history of differentiated thyroid cancers. The right selection of individuals with better prognosis, for whom more aggressive curative treatment was indicated, requires a better understanding of the features of bone involvement. [ABSTRACT FROM AUTHOR]

The removal of volatile Cs and I compounds from an air flow on various filtering elements was studied. I and CsOH are sorbed on basalt wool, but the degree of their recovery is low: ∼86 and 90-93%, respectively, at the basalt wool bed height of 15-18 cm. The use of a cascade of bubblers in combination with a column packed with basalt wool allows virtually complete (>99.9%) removal of I and Cs in the form of I, CsI, and CsOH from an air flow. [ABSTRACT FROM AUTHOR]

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 I, although significant loss of target material may occur in heating process. In dry distillation technique no chemical was added to irradiated target material. After I separation tellurium dioxide was decayed for 8 years in radioactive waste management facility. The decayed TeO was recovered, melted and crushed for desired mesh size. The TeO was sealed in Al capsule for re-irradiation purposes. The separation of I was carried out via dry distillation. The purity and yield of I separated from both of the irradiated new and irradiated re-used tellurium dioxide targets were comparable. [ABSTRACT FROM AUTHOR]

Fission products, especially131I,134Cs and137Cs, from the damaged Fukushima Dai-ichi nuclear power plant (NPP) were detected in many places worldwide shortly after the accident caused by natural disaster. To observe the spatial and temporal variation of these isotopes in Hungary, aerosol samples were collected at five locations from late March to early May 2011: Institute of Nuclear Research, Hungarian Academy of Sciences (ATOMKI, Debrecen, East Hungary), Paks NPP (Paks, South-Central Hungary) as well as at the vicinity of Aggtelek (Northeast Hungary), Tapolca (West Hungary) and Bátaapáti (Southwest Hungary) settlements. In addition to the aerosol samples, dry/wet fallout samples were collected at ATOMKI, and airborne elemental iodine and organic iodide samples were collected at Paks NPP. The peak in the activity concentration of airborne131I was observed around 30 March (1–3 mBq m−3both in aerosol samples and gaseous iodine traps) with a slow decline afterwards. Aerosol samples of several hundred cubic metres of air showed134Cs and137Cs in detectable amounts along with131I. The decay-corrected inventory of131I fallout at ATOMKI was 2.1±0.1 Bq m−2at maximum in the observation period. Dose-rate contribution calculations show that the radiological impact of this event at Hungarian locations was of no considerable concern. [ABSTRACT FROM AUTHOR]

Protocols in the management of differentiated thyroid cancer, recommend adequate thyroid stimulating hormone (TSH) stimulation for radioactive 131I administrations, both for imaging and subsequent ablations. Commonly followed method is to achieve this by endogenous TSH stimulation by withdrawal of thyroxine. Numerous studies worldwide have reported comparable results with recombinant human thyroid stimulating hormone (rhTSH) intervention as conventional thyroxine hormone withdrawal. Radiation safety applications call for the need to understand radioactive 131I (RA131I) clearance pattern to estimate whole body doses when this new methodology is used in our institution. A study of radiation body burden estimation was undertaken in two groups of patients treated with RA131I; (a) one group of patients having thyroxine medication suspended for 5 weeks prior to therapy and (b) in the other group retaining thyroxine support with two rhTSH injections prior to therapy with RA131I. Sequential exposure rates at 1 m in the air were measured in these patients using a digital auto-ranging beta gamma survey instrument calibrated for measurement of exposure rates. The mean measured exposure rates at 1 m in µSv/h immediately after administration and at 24 h intervals until 3 days are used for calculating of effective ² time of clearance of administered activity in both groups of patients, 81 patients in conventionally treated group (stop thyroxine) and 22 patients with rhTSH administration. The 131I activities ranged from 2.6 to 7.9 GBq. The mean administered 131I activities were 4.24 ± 0.95 GBq (n = 81) in "stop hormone" group and 5.11 ± 1.40 GBq (n = 22) in rhTSH group. The fall of radioactive body burden showed two clearance patterns within observed 72 h. Calculated T²eff values were 16.45 h (stop hormone group) 12.35 h (rhTSH group) for elapsed period of 48 h. Beyond 48 h post administration, clearance of RA131I takes place with T²eff > 20 h in both groups. Neck and stomach exposure rate measurements showed reduced uptakes in the neck for rhTSH patients compared with "stop thyroxine" group and results are comparable with other studies. Whole body clearance is faster for patients with rhTSH injection, resulting in less whole body absorbed doses, and dose to blood. These patients clear circulatory radioactivity faster, enabling them to be discharged sooner, thus reduce costs of the hospitalization. Reduction in background whole body count rate may improve the residual thyroid images in whole body scan. rhTSH provides TSH stimulation without withdrawal of thyroid hormone and hence can help patients to take up therapy without hormone deficient problems in the withdrawn period prior to RA131I therapy. This also will help in reducing the restriction time periods for patients to mix up with the general population and children. [ABSTRACT FROM AUTHOR]

Abstract: Two methods for determination of internal dose due to 131I intake during the preparation and handling of iodine radiopharmaceutical products have been compared. The first method was based on the measurement of 131I in 24-hour urine samples while the second method was based on the measurement in vivo of 131I in thyroid. The results have shown that urine analysis method can be used as a screening test but not for internal dose assessment of exposed workers. Thyroid monitoring method was found to be more reliable and accurate method for assessing internal dose from 131I intake. In addition, the assessed internal dose showed that the annual internal effective dose for some workers was below 1mSv with no risk classification, whereas the results of other group of workers were between 1 and 6mSv with low risk classification. Only one worker reached 7.66mSv with high risk classification; and this worker must be monitored individually. [Copyright &y& Elsevier]