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Sample records for additional thyroid dose

  1. Thyroid-Hormone–Disrupting Chemicals: Evidence for Dose-Dependent Additivity or Synergism

    Crofton, Kevin M.; Craft, Elena S.; Hedge, Joan M.; Gennings, Chris; Simmons, Jane E.; Carchman, Richard A.; Carter, W Hans; DeVito, Michael J.

    2005-01-01

    Endocrine disruption from environmental contaminants has been linked to a broad spectrum of adverse outcomes. One concern about endocrine-disrupting xenobiotics is the potential for additive or synergistic (i.e., greater-than-additive) effects of mixtures. A short-term dosing model to examine the effects of environmental mixtures on thyroid homeostasis has been developed. Prototypic thyroid-disrupting chemicals (TDCs) such as dioxins, polychlorinated biphenyls (PCBs), and poly-brominated diph...

  2. Additional thyroid dose factor from transportation sources in Russia after the Chernobyl disaster.

    Parshkov, E M; Chebotareva, I V; V.A. Sokolov; Dallas, C E

    1997-01-01

    Beginning approximately 4 years after the Chernobyl nuclear accident a steady increase in the incidence of thyroid cancer was observed in children and adolescents of the Bryansk Oblast, which received the highest level of radionuclide contaminants in Russia. We examined the spatial relationship between the residence location of patients with identified thyroid cancer (0-18 years old at the time of the accident) and a number of geographic parameters to better account for the etiology of thyroi...

  3. Required therapeutic dose of 131I for thyroid ablation after surgery for differentiated thyroid carcinoma

    Full text of publication follows. After operation for carcinoma of the thyroid gland a lot of patients are treated with radioactive iodine for ablation of the residual thyroid parenchyma. Aim: to determine the appropriate dose of radioactive iodine for ablation of the residual thyroid parenchyma in patients operated for differentiated thyroid carcinoma. Materials and methods: the study includes 316 patients who underwent a whole-body scan (WBS) scintigraphy with 131I. From 2009 to 2012 year 632 images were taken. Patients range from 21 to 78 years old. The scan was performed on a dual-headed gamma camera Siemens after an oral reception of a diagnostic dose 131I (2 mCi). The remnants of thyroid parenchyma were registered in 67 of the patients. 39 patients with registered remnants of thyroid parenchyma and slightly elevated thyroglobulin (TG) values who took therapeutic dose 131I (80-100 mCi) underwent a WBS scintigraphy with 131I and did not display remnants of thyroid parenchyma or extra thyroid accumulation of the radio nucleotide. 23 patients with several remnants of thyroid parenchyma and elevated values of TG who underwent a WBS scintigraphy with 131I eight to ten months after reception of the first dose therapeutic iodine (80-100 mCi) displayed persisting remnants of thyroid parenchyma. They were treated with a second dose of 131I (50-100 mCi). In 5 patients with high values of TG besides the thyroid remnants 3 of the patients displayed an extra thyroid accumulation in the lungs and 2 of them displayed an extra-thyroid fixation in the thoracic vertebras in addition to the fixation in the lungs. These 5 patients were treated twice with 131I, but still displayed the remnants of thyroid parenchyma and extra thyroid fixation. That group was treated with a third dose of 131I (30-50 mCi) and no remnants of thyroid parenchyma and extra-thyroid fixation of the radio nucleotide were visualized on the control WBS scintigraphy. Conclusion: in the majority of the patients

  4. Estimating thyroid dose in pediatric CT exams from surface dose measurement

    The purpose of this study was to investigate the possibility of estimating pediatric thyroid doses from CT using surface neck doses. Optically stimulated luminescence dosimeters were used to measure the neck surface dose of 25 children ranging in ages between one and three years old. The neck circumference for each child was measured. The relationship between obtained surface doses and thyroid dose was studied using acrylic phantoms of various sizes and with holes of different depths. The ratios of hole-to-surface doses were used to convert patients' surface dose to thyroid dose. ImPACT software was utilized to calculate thyroid dose after applying the appropriate age correction factors. A paired t-test was performed to compare thyroid doses from our approach and ImPACT. The ratio of thyroid to surface dose was found to be 1.1. Thyroid doses ranged from 20 to 80 mGy. Comparison showed no statistical significance (p = 0.18). In addition, the average of surface dose variation along the z-axis in helical scans was studied and found to range between 5% (in 10 cm diameter phantom/24 mm collimation/pitch 1.0) and 8% (in 16 cm diameter phantom/12 mm collimation/pitch 0.7). We conclude that surface dose is an acceptable predictor for pediatric thyroid dose from CT. The uncertainty due to surface dose variability may be reduced if narrower collimation is used with a pitch factor close to 1.0. Also, the results did not show any effect of thyroid depth on the measured dose. (paper)

  5. The reconstruction of thyroid dose following Chernobyl

    The report presents the overview of several approaches in working out the methods of thyroid internal dose reconstruction following Chernobyl. One of these approaches was developed (IBPh, Moscow; MRRC, Obninsk; IRM, Minsk) using the correlations between the mean dose calculation based on I131 thyroid content measurements and Cs137 contamination of territories. The available data on I131 soil contamination were taken into account. The lack of data on I131 soil contamination was supposed to be compensated by I129 measurements in soil samples from contaminated territories. The semiempiric model was developed for dose reconstruction. The comparison of the results obtained by semiempiric model and empirical values are presented. The estimated values of average dose according semiempiric model were used for individual dose reconstruction. The IRH (St.-Petersburg) has developed the following method for individual dose reconstruction: correlation between the total I131 radioiodine incorporation in thyroid and whole body Cs137 content during first months after accident. The individual dose reconstruction is also mentioned to be performed using the data on individual milk consumption during first weeks after accident. For evaluation of average doses it is suggested to use the linear correlation: thyroid dose values based on radioiodine thyroid measurements vs Cs137 contamination, air kerma rate, mean I131 concentration in the milk. The method for retrospective reconstruction of thyroid dose caused by short-living iodine nuclides released after the Chernobyl accident has been developed by Research Centre, Juelich, Germany. It is based on the constant ratio that these nuclides have with the long-living I129. The contamination of soil samples by this nuclide can be used to assess thyroid doses. First results of I129 contamination values and derived thyroid doses are to be presented

  6. Thyroid dose in children undergoing prophylactic cranial irradiation

    Purpose: To determine the radiation dose received by the thyroid gland as a result of prophylactic cranial irradiation (PCI) in childhood leukemia and the factors influencing that dose. Methods and Materials: The dose to the thyroid resulting from simulated cranial irradiation with parallel opposed lateral fields of an adult anthropomorphic (ART) phantom with both 6 MV X-rays and Cobalt-60 γ-rays was measured using thermoluminescent dosimeters (TLDs). The dependence of thyroid dose on the distance of the field from the thyroid and the proportions of thyroid dose from stray radiation (leakage, scatter from jaws, etc.) and tissue scattered radiation were measured. The effects of a shadow tray and shielding blocks were also determined. Calculation of thyroid dose using the Clarkson scatter integration method was performed for 6 MV X-rays to compare with the measured doses. In vivo thyroid dose estimates were made using TLD measurements for three children receiving PCI with 6 MV X-rays. Results: Using open, unshielded fields, the thyroid region of the phantom received 1.2-1.4% of the prescribed cranial dose for 6 MV X-rays and 1.5-1.7% for Cobalt-60. For both treatment units, stray radiation accounted for approximately two thirds of the thyroid dose and tissue scatter accounted for the remaining one third. The thyroid dose increased as the field moved closer to the thyroid, with an increasing proportion of the dose due to tissue scatter. Placement of a thyroid shielding block on a shadow tray reduced the thyroid dose by only 20% compared with the open, unshielded setup. Thyroid dose from 6 MV using open fields was affected by the orientation of the collimator. When the inferior field edge was defined by the lower jaw, the dose was reduced by 27% compared with the upper jaw. Good correlation of dose to the thyroid region was obtained between phantom measured doses, in vivo measured doses and calculation of dose using the Clarkson method. Conclusion: For PCI doses of

  7. Thyroid absorbed dose using TLDs during mammography

    Gonzalez A, M.; Melendez L, M. [IPN, Centro de Investigacion y de Estudios Avanzados, Av. IPN 2508, Col. San Pedro Zacatenco, 07360 Mexico D. F. (Mexico); Davila M, P., E-mail: biomedica.sst@gmail.com [UNEME-DEDICAM de Ciudad Victoria, Circuito Medico s/n, 87087 Ciudad Victoria, Tamaulipas (Mexico)

    2015-10-15

    Full text: In this study, the mean glandular dose (MGD) and the thyroid dose (D Thy) were measured in 200 women screened with mammography in Cranio caudal (Cc) and mediolateral oblique projections. All mammograms were performed with Giotto-Ims (6000-14-M2 Model) equipment, which was verified to meet the criteria of quality of NOM-229-Ssa-2002. During audits performance and HVL, for each anode filter combinations was measured with the camera Radcal mammography equipment 10 X 6-6M (HVL = 0.26 mm Al). D Thy measurements were performed with TLD dosimeters (LiF:Mn) , that were read with the Harshaw 3500 TLD reader. The MGD, was obtained according to the UK and European protocols for mammographic dosimetry using a plane parallel chamber (Standard Imaging, Model A-600) calibrated by a radiation beam UW-23-Mo (= 0.279 mm Al HVL). A comparative statistical analysis was carried out with the measured MGD and D thy. The thyroid mean dose was 0.063 mGy and 0.078 mGy for Cc and mediolateral oblique respectively. There is a linear correlation between the MGD and the D Thy slightly influenced by the anode-filter combination. Using a 95% for the confidence interval in MGD (1.07 mGy), the 90% of measurements are in agreement with the established uncertainty limits. The D Thy are lower than the MGD. There is no risk for cancer induction in thyroid in women due to mammography screening. (Author)

  8. Thyroid absorbed dose using TLDs during mammography

    Full text: In this study, the mean glandular dose (MGD) and the thyroid dose (D Thy) were measured in 200 women screened with mammography in Cranio caudal (Cc) and mediolateral oblique projections. All mammograms were performed with Giotto-Ims (6000-14-M2 Model) equipment, which was verified to meet the criteria of quality of NOM-229-Ssa-2002. During audits performance and HVL, for each anode filter combinations was measured with the camera Radcal mammography equipment 10 X 6-6M (HVL = 0.26 mm Al). D Thy measurements were performed with TLD dosimeters (LiF:Mn) , that were read with the Harshaw 3500 TLD reader. The MGD, was obtained according to the UK and European protocols for mammographic dosimetry using a plane parallel chamber (Standard Imaging, Model A-600) calibrated by a radiation beam UW-23-Mo (= 0.279 mm Al HVL). A comparative statistical analysis was carried out with the measured MGD and D thy. The thyroid mean dose was 0.063 mGy and 0.078 mGy for Cc and mediolateral oblique respectively. There is a linear correlation between the MGD and the D Thy slightly influenced by the anode-filter combination. Using a 95% for the confidence interval in MGD (1.07 mGy), the 90% of measurements are in agreement with the established uncertainty limits. The D Thy are lower than the MGD. There is no risk for cancer induction in thyroid in women due to mammography screening. (Author)

  9. Reconstruction of radiation doses to the thyroid of children in Belarus suffering from thyroid gland cancer

    About four years after the reactor accident of Chernobyl a pronounced rise in childhood tyroid gland cancer was registered throughout the republic of Belarus. It was soon understood that most likely the short-lived radioiodine isotope 131I was responsible for this effect. Therefore, methods had to be developed to reconstruct the tyroid dose of those children who suffered from thyroid cancer. To assess the tyroid dose the concentration of 131 I in soil was then determined using the assumption of a constant release and transport ratio between 129I and 131I. The inferred 131I-deposition densities on ground were used as input data to a radiological food-chain model and an average integrated tyroid dose to certain age groups of various residence areas were calculated for the main exposure path of milk ingestion. An intercomparison between this new approach and the results of direct thyroid activity measurements was performed. In addition to these two approaches two others were applied for comparison. The first one was based on the generalisation of a correlation between the 137Cs-deposition density and a few 131I-measurements. The second approach was based on the determination of 131I-deposition by an atmospheric dispersion model. It turned out that the values which resulted from the 129I-method were higher but still closer to those of the direct measurements than the other two approaches. Thyroid doses inferred by the 129I-method generally ranged between 1 and 100 Sv, depending on the mode of deposition, whereas the values of the direct measurements were found to be in the range of 0.5-5 Sv. The two model approaches applying caesium deposition densities and atmospheric dispersion calculations of radioiodine resulted in lower thyroid exposures ranging between 0.001 and 1.0 Sv only. (orig./MG)

  10. Thyroid doses and risk to paediatric patients undergoing neck CT examinations

    To estimate thyroid doses and cancer risk for paediatric patients undergoing neck computed tomography (CT). We used average CTDIvol (mGy) values from 75 paediatric neck CT examinations to estimate thyroid dose in a mathematical anthropomorphic phantom (ImPACT Patient CT Dosimetry Calculator). Patient dose was estimated by modelling the neck as mass equivalent water cylinder. A patient size correction factor was obtained using published relative dose data as a function of water cylinder size. Additional correction factors included scan length and radiation intensity variation secondary to tube-current modulation. The mean water cylinder diameter that modelled the neck was 14 ± 3.5 cm. The mathematical anthropomorphic phantom has a 16.5-cm neck, and for a constant CT exposure, would have thyroid doses that are 13-17 % lower than the average paediatric patient. CTDIvol was independent of age and sex. The average thyroid doses were 31 ± 18 mGy (males) and 34 ± 15 mGy (females). Thyroid cancer incidence risk was highest for infant females (0.2 %), lowest for teenage males (0.01 %). Estimated absorbed thyroid doses in paediatric neck CT did not significantly vary with age and gender. However, the corresponding thyroid cancer risk is determined by gender and age. (orig.)

  11. Thyroid doses and risk to paediatric patients undergoing neck CT examinations

    Spampinato, Maria Vittoria; Tipnis, Sameer; Huda, Walter [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Tavernier, Joshua [Medical University of South Carolina, College of Medicine, Charleston, SC (United States)

    2015-07-15

    To estimate thyroid doses and cancer risk for paediatric patients undergoing neck computed tomography (CT). We used average CTDI{sub vol} (mGy) values from 75 paediatric neck CT examinations to estimate thyroid dose in a mathematical anthropomorphic phantom (ImPACT Patient CT Dosimetry Calculator). Patient dose was estimated by modelling the neck as mass equivalent water cylinder. A patient size correction factor was obtained using published relative dose data as a function of water cylinder size. Additional correction factors included scan length and radiation intensity variation secondary to tube-current modulation. The mean water cylinder diameter that modelled the neck was 14 ± 3.5 cm. The mathematical anthropomorphic phantom has a 16.5-cm neck, and for a constant CT exposure, would have thyroid doses that are 13-17 % lower than the average paediatric patient. CTDI{sub vol} was independent of age and sex. The average thyroid doses were 31 ± 18 mGy (males) and 34 ± 15 mGy (females). Thyroid cancer incidence risk was highest for infant females (0.2 %), lowest for teenage males (0.01 %). Estimated absorbed thyroid doses in paediatric neck CT did not significantly vary with age and gender. However, the corresponding thyroid cancer risk is determined by gender and age. (orig.)

  12. Results of large scale thyroid dose reconstruction in Ukraine

    In 1993, the Ukrainian Ministry on Chernobyl Affairs initiated a large scale reconstruction of thyroid exposures to radioiodine after the Chernobyl accident. The objective was to provide the state policy on social compensations with a scientific background. About 7000 settlements from five contaminated regions have gotten certificates of thyroid exposure since then. Certificates contain estimates of the average thyroid dose from 131I for seven age groups. The primary dose estimates used about 150000 direct measurements of the 131I activity in the thyroid glands of inhabitants from Chernigiv, Kiev, Zhytomyr, and also Vinnytsa regions. Parameters of the assumed intake function were related to environmental and questionnaire data. The dose reconstruction for the remaining territory was based on empirical relations between intake function parameters and the 137Cs deposition. The relationship was specified by the distance and the direction to the Chernobyl Nuclear Power Plant. The relations were first derived for territories with direct measurements and then they were spread on other areas using daily iodine releases and atmospheric transportation routes. The results of the dose reconstruction allowed to mark zones on the territory of Ukraine according to the average levels of thyroid exposures. These zones underlay a policy of post-accidental health care and social compensations. Another important application of the thyroid dose reconstruction is the radiation risk assessment of thyroid cancer among people exposed during childhood due to the Chernobyl accident

  13. Thyroid cancer development in Chernobyl including new additional results

    Full text: We have been studying the etiology of thyroid cancer development among the exposed people in Hiroshima. In 1993, we have proposed the hypothesis of oncology model of thyroid cancer development in children following the nuclear power plant accident in Chernobyl, and then related studies has been done in Chernobyl and also in Hiroshima. Following findings are included. Urinary iodine level was lower in Chernobyl than in Hiroshima. Stimulation of ret oncogene in thyroid cancer tissues, and appearance of nuclear abnormalities of thyroid follicular cells were found higher rate among the exposed people. Sensitivity of TSH-receptor in thyroid tissues (TSH-R mRNA expression) was higher while young. Synergistic effect of TSH-R mRNA and ER mRNA expressions were found in both of normal tissues and cancer tissues in thyroid, but it was more apparent in cancer tissues. These findings gave the additional proofs on the hypothesis of thyroid cancer development in Chernobyl. Including these results, we like to present the importance of thyroid for the health of the exposed people in Chernobyl

  14. Thyroid doses for evacuees from the Fukushima nuclear accident

    Tokonami, Shinji; Hosoda, Masahiro; Akiba, Suminori; Sorimachi, Atsuyuki; Kashiwakura, Ikuo; Balonov, Mikhail

    2012-07-01

    A primary health concern among residents and evacuees in affected areas immediately after a nuclear accident is the internal exposure of the thyroid to radioiodine, particularly I-131, and subsequent thyroid cancer risk. In Japan, the natural disasters of the earthquake and tsunami in March 2011 destroyed an important function of the Fukushima Daiichi Nuclear Power Plant (F1-NPP) and a large amount of radioactive material was released to the environment. Here we report for the first time extensive measurements of the exposure to I-131 revealing I-131 activity in the thyroid of 46 out of the 62 residents and evacuees measured. The median thyroid equivalent dose was estimated to be 4.2 mSv and 3.5 mSv for children and adults, respectively, much smaller than the mean thyroid dose in the Chernobyl accident (490 mSv in evacuees). Maximum thyroid doses for children and adults were 23 mSv and 33 mSv, respectively.

  15. X-ray and radioiodine dose to thyroid follicular cells

    Faw, R.E. (Kansas State Univ., Manhattan, KS (USA). Dept. of Nuclear Engineering); Eckerman, K.F.; Ryman, J.C. (Oak Ridge National Lab., TN (USA))

    1991-01-01

    Radiation doses to the epithelial cells of thyroid follicles have been calculated for internal exposure by radionuclides of iodine and by secondary radiations created as a result of interactions of externally administered x rays with iodine naturally occurring in the thyroid. Calculations were performed for the thyroids of subjects ranging from the newborn to the adult male. Results for internal radionuclides are reported as the dose rate to follicular-cell nuclei per unit specific activity of the radionuclide in the thyroid as a whole, i.e., as the specific S value'' as used in the MIRD method for internal dosimetry. Results for x rays are reported as the response function, i.e., the absorbed dose per unit fluence of primary x rays. Dose rates are subdivided into internal and external components, the former from radiations emitted within the colloid volume of any one follicle, and the latter from radiations emitted throughout the thyroid in follicles surrounding that one follicle. 37 refs., 5 figs., 3 tabs.

  16. Automated objective thyroid ablation dose calculations using interactive computer program

    Aim: Development of an interactive computer program allowing automatic calculation of an optimized dose of I-131 required for the effective ablation of remnants of thyroid tissue. Materials and methods: The Standard Thyroid Uptake Neck Phantom (Nucl.Assoc.) was used for measurements of efficiency of high energy (for I-131) and low energy (for I-123) collimator mounted on the Picker Prism 2000 gamma camera. The efficiency was calculated for a wide range of distances between the patient's neck and the camera head and for different sizes of remnant thyroid tissue and activities. These data were built into the computer memory (Picker Odyssey FX 729) and then were used for calculation of percentage uptake in the neck (regular quality control and maintenance of gamma camera secures the stability of its performance). On the basis of the uptake on an early and late image after the administration of radioisotope, its biological and effective half lives in the patient are calculated and the dose required for delivery of 50mGy per gram of I-131 radiation to the remaining thyroid tissue is evaluated. Results: The technologist selects the appropriate isotope, enters the patient's dose and the neck to collimator distance then draws the regions of interests around the thyroid remnants on each of anterior images. No other operator interventions are required. When regions are assigned the percentage uptake, biological half life, effective half life and required I-131 activity in MBq per gram are calculated automatically. It was found that efficiency is independent of activity over the range seen clinically. The need for a standard is eliminated and automated calculations ensure accuracy. Estimation of remnant mass and desired radiation dose is required to complete the dose calculations. The program works for both I-131 (using 1 to 3 day and 5 to 10 day images) and I-123 (using 6 and 24 hrs images). The program automatically corrects for the exact imaging time. Results are displayed

  17. Low dose irradiation of thyroid cells reveals a unique transcriptomic and epigenetic signature in RET/PTC-positive cells

    Abou-El-Ardat, Khalil, E-mail: kabouela@sckcen.be [Radiobiology Unit, Molecular and Cellular Biology, GKD Building, Studiecentrum voor Kernenergie - Centre d' Etude de l' Energie Nucleaire (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Universiteit Gent, 9000 Ghent (Belgium); Monsieurs, Pieter [Radiobiology Unit, Molecular and Cellular Biology, GKD Building, Studiecentrum voor Kernenergie - Centre d' Etude de l' Energie Nucleaire (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Anastasov, Natasa; Atkinson, Mike [Department of Radiation Sciences, Helmholtz Zentrum Muenchen, Munich (Germany); Derradji, Hanane [Radiobiology Unit, Molecular and Cellular Biology, GKD Building, Studiecentrum voor Kernenergie - Centre d' Etude de l' Energie Nucleaire (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); De Meyer, Tim [Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Universiteit Gent, 9000 Ghent (Belgium); Department of Applied Mathematics, Biometrics and Process Control, Faculty of Bioscience Engineering, Universiteit Gent, 9000 Ghent (Belgium); Bekaert, Sofie [Clinical Research Center, Faculty for Medicine and Health Sciences, Universiteit Gent, 185 De Pintelaan, 9000 Ghent (Belgium); Van Criekinge, Wim [Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Universiteit Gent, 9000 Ghent (Belgium); and others

    2012-03-01

    The high doses of radiation received in the wake of the Chernobyl incident and the atomic bombing of Hiroshima and Nagasaki have been linked to the increased appearance of thyroid cancer in the children living in the vicinity of the site. However, the data gathered on the effect of low doses of radiation on the thyroid remain limited. We have examined the genome wide transcriptional response of a culture of TPC-1 human cell line of papillary thyroid carcinoma origin with a RET/PTC1 translocation to various doses (0.0625, 0.5, and 4 Gy) of X-rays and compared it to response of thyroids with a RET/PTC3 translocation and against wild-type mouse thyroids irradiated with the same doses using Affymetrix microarrays. We have found considerable overlap at a high dose of 4 Gy in both RET/PTC-positive systems but no common genes at 62.5 mGy. In addition, the response of RET/PTC-positive system at all doses was distinct from the response of wild-type thyroids with both systems signaling down different pathways. Analysis of the response of microRNAs in TPC-1 cells revealed a radiation-responsive signature of microRNAs in addition to dose-responsive microRNAs. Our results point to the fact that a low dose of X-rays seems to have a significant proliferative effect on normal thyroids. This observation should be studied further as opposed to its effect on RET/PTC-positive thyroids which was subtle, anti-proliferative and system-dependent.

  18. Low dose irradiation of thyroid cells reveals a unique transcriptomic and epigenetic signature in RET/PTC-positive cells.

    Abou-El-Ardat, Khalil; Monsieurs, Pieter; Anastasov, Nataša; Atkinson, Mike; Derradji, Hanane; De Meyer, Tim; Bekaert, Sofie; Van Criekinge, Wim; Baatout, Sarah

    2012-03-01

    The high doses of radiation received in the wake of the Chernobyl incident and the atomic bombing of Hiroshima and Nagasaki have been linked to the increased appearance of thyroid cancer in the children living in the vicinity of the site. However, the data gathered on the effect of low doses of radiation on the thyroid remain limited. We have examined the genome wide transcriptional response of a culture of TPC-1 human cell line of papillary thyroid carcinoma origin with a RET/PTC1 translocation to various doses (0.0625, 0.5, and 4Gy) of X-rays and compared it to response of thyroids with a RET/PTC3 translocation and against wild-type mouse thyroids irradiated with the same doses using Affymetrix microarrays. We have found considerable overlap at a high dose of 4Gy in both RET/PTC-positive systems but no common genes at 62.5mGy. In addition, the response of RET/PTC-positive system at all doses was distinct from the response of wild-type thyroids with both systems signaling down different pathways. Analysis of the response of microRNAs in TPC-1 cells revealed a radiation-responsive signature of microRNAs in addition to dose-responsive microRNAs. Our results point to the fact that a low dose of X-rays seems to have a significant proliferative effect on normal thyroids. This observation should be studied further as opposed to its effect on RET/PTC-positive thyroids which was subtle, anti-proliferative and system-dependent. PMID:22027090

  19. Methodology of thyroid dose reconstruction for population of Russia after the Chernobyl accident

    The Chernobyl accident has provoked radioactive contamination upon such extensive territories that the monitoring of short-lived iodine isotopes and estimation of their influence upon people were performed with a delay or not completely. So for solving the problem of dose estimation for thyroid exposure with iodine radionuclides among the population of contaminated territories, it was necessary to analyze retrospectively the existing data and to develop a model of the thyroid dose reconstruction. The reconstruction procedure for the average for a settlement thyroid dose in Russians has been worked out basing on the following data received in May-June 1986: 44 thousand measurements of I-131 content in the thyroid of inhabitants; 2000 gamma-spectrometric measurements of milk samples in Tula region; about 3500 measurements of total beta-activity in milk samples from Bryansk, Kaluga and Orel regions; over 100 radiochemical analysis of milk samples for I and Cs radionuclides' content; about 14000 thousand polls of inhabitants and local administration authorities upon the regime of behavior, milk consumption, cattle pasture dates and countermeasures in May 1986; the data of Roshydromet upon Cs-137 contamination of soil in settlements. The individual dose estimations by direct measurements of I-131 in the thyroid have been accepted as the basis for dose reconstruction. When counting the I-131 activity in the thyroid the additional radiation from cesium radionuclides distributed in extra-thyroidal tissues were excluded. Without this amendment the doses in the later terms of measurements could be 2-5 times overestimated. Because of the limited input data for dose calculations a formalized model of radioiodine intake into human body was used. The parameters of this model were based upon the analysis of the radiation monitoring data. According to the model daily intake of iodine-131 was constant within 10 days after radioactive fallout, and further on reduced proportionally

  20. Optimization of the therapeutic dose of 131I for thyroid differentiated carcinoma

    I-131 thyroid cancer therapy is based on the strategy of concentrating radioactive iodine in the thyroid tissue, to completetly eliminate thyroid tissue and functioning thyroid cancer metastases remaining after thyroidectomy. In Brazil, fixed activities of 131 I generally are given, sometimes either delivering insufficient activities to ablate all of the remnants, or unnecessarily high activities, with patients remaining in the hospital for some period of time. This investigation proposes a protocol of individualized planning of ablative doses, based on individual patients metabolisms and measured thyroid remnant masses. Simulated thyroid remnants were fabricated in various forms, volumes and activities, and optimum image acquisition parameters were determined using Single-Photon Emission Computed Tomography 9SPECT). Resultant images were evaluated, to determine the apparent volumes and the 131 I concentrations. I-131 metabolism was studied in 9 patients who had undergone thyroidectomies. Their thyroid remnant masses were determined applying the same parameters used in SPECT simulation studies, and the optimum activity for their therapy was calculated and compared to the established fixed activity of 3.7 GBq (100 mCi), which would have normally been assigned. Background subtraction using the method of percent maximum counts, using a value of 67.5%, combined with scatter correction (triple energy window method), was shown to be optimum for SPECT quantification of volumes between 3-10 ml. Errors in the method were below 9% for sources with regular geometries and around 11% for sources with irregular geometries. In the patient studies, it was observed that 78% of patients could have received reduced activities of 131 (from 0.8-3-2. GBq (20-87 nCi). In addition, 33% of these patients could have received low enough activities to have discharged from the hospital, using an individualized administration scheme. This could also have resulted in a dose reduction for many

  1. Dose-response relationships for radiation-induced thyroid cancer and thyroid nodules: Evidence for the prolonged effects of radiation on the thyroid

    The risk of developing thyroid cancer and other thyroid neoplasms after radiation exposure is well known, but specific modifiers of the dose-response relationship are not. The authors have identified 4,296 subjects who received treatment before their sixteenth birthday with orthovoltage radiation for benign conditions in the head and neck area. Individual thyroid dose estimates were calculated for 3,843 subjects. Of the 2,634 subjects who have been found, 1,043 have developed thyroid nodules of all types, and 309 have developed thyroid cancer. The radiation dose-response relationship was consistent with a linear excess relative risk model for thyroid cancer and thyroid nodules within the range of observed doses. Women developed thyroid cancer and thyroid nodules at a higher rate, but the slopes of the dose-response curves were the same for men and women. Age at radiation exposure was a significant factor of the risk, with a lower age at exposure associated with a higher risk. To determine the effect of the wide publicity and the screening program, which began in 1974, the authors compared the dose-response relationship for cases diagnosed before and after 1974. The overall rates increased dramatically after 1974, but the estimates of the slopes of the dose-response curves were not statistically different. The slope of the dose-response curve for thyroid neoplasms appears to have reached a maximum 25-29 yr after radiation exposure, but the dose response continued to be elevated at the end of follow-up. These data are consistent with the tumorigenic effects of radiation lasting at least 40 yr

  2. Thyroid

    In vivo thyroid function testing is conducted with isotopes of iodine, the rate-limiting substrate for thyroid hormonogenesis, or with pertechnetate, an anion which the thyroidal follicular cells will concentrate or trap similarly to iodide, but will not organify. The physical characteristics of these isotopes, their advantages or indications, their disadvantages, and the average radiation dose to the thyroid in the infant, child, and adult are reviewed. The latter is expressed as estimated dose in rads per microcurie administered assuming an uptake of 27 percent and a biological half-life of 68 days. For many years the standard isotope for thyroid studies has been 131I. This isotope, however, has the disadvantage of a high radiation dose to the gland, especially in infants and children. Furthermore the high-energy gamma ray (364 keV) requires low-efficiency, thick septal collimators for scanning. More recently 125I, 123I, and 99/sup m/Tc-pertechnetate have been used. (auth)

  3. Estimating individual thyroid doses for a case-control study of childhood thyroid cancer in Bryansk Oblast, Russia

    Following the Chernobyl accident, radioactive fission products, including 131I in 137Cs, were deposited in Bryansk Oblast in Russia. Intakes of radio-iodines, mainly 131I in milk, were the principal sources of radiation doses to thyroids of residents of the contaminated areas, but those radionuclides decayed before detailed contamination surveys could be performed. As a result, 137Cs deposition density is the primary measure of the contamination due to the accident and there are relatively few measurements of the ratio of 131I to 137Cs in vegetation or soil samples from this area. Although many measurements of radiation emitted from the necks of residents were performed and used to estimate thyroidal 131I activities and thyroid doses, such data are not available for all subjects. The semi-empirical model was selected to provide a dose calculation method to be applied uniformly to cases and controls in the study. The model was developed using dose estimates from direct measurements of 131I in adult thyroids, and relates settlement average thyroid doses to 137Cs contamination levels and ratios of 131I to 137Cs. This model is useful for areas where thyroid monitoring was not performed and can be used to estimate doses to exposed individuals. For application to children in this study, adjustment factors are used to address differences in age-dependent intake rates and thyroid dosimetry. Other individual dietary factors and sources (private/public) of milk consumed are reflected in the dose estimates. Countermeasures that reduced thyroid dose, such as cessation of milk consumption and intake of stable iodine, are also considered for each subject. The necessary personal information of subjects was obtained by interview, most frequently of their mothers, using a questionnaire developed for the study. Uncertainties in thyroid dose, estimated using Monte Carlo techniques, are presented for reference conditions. Thyroid dose estimates for individual children made using the

  4. Bone marrow and thyroid absorbed doses from mammography

    Breast dose from mammography has been estimated by various investigators, because of the established effectiveness of mammography in early screening for breast cancer and the relatively high sensitivity of the breast to radiation carcinogenesis. Nevertheless, to our knowledge, there is no available information in the literature about absorbed doses from mammography to organs other than the breast. The absorbed doses to the red bone marrow in the sternum and to the thyroid, due to scattered radiation from mammographic examinations, have been measured using a Plexiglas upper-body phantom and thermoluminescent dosemeters. Their dependence on several parameters has also been examined. It is necessary to emphasize that this work is still in progress. (author)

  5. Thyroid autoantibodies post moderate doses of iodized oil in adolescence

    In this study we examined the effect of a single moderate doses of iodized oil(400 mg) on the production of thyroid autoantibodies, namely thyroid peroxidase(TPO), thyroglobulin(TG), and TSH - receptor(TRAB) antibodies.This is compared with daily dose of 100 mg of L-thyroxine for 6 months.A group of 87 adolescent school girls were selected from a moderately iodine deficient area, on the basis of having goitre grade Ib and above(WHO classification).Randomly the girls were divided into two groups: Group 1 received L-thyroxine (n =46).Group 2 received oral iodized oil (n =41).The prevalence of TPO Ab in the whole group before treatment was 3.4%.No significant level of TRAB was detected in any of the girls before or after treatment. All the patients who had TPO Ab or TG Ab at the start of the study were found to be in group 1, this happened by chance because all the samples were not tested until the end of the study.No patient in group 2 found to have any of the antibodies.By the end of the 14 months follow up period one patient from group 1, who had no TPO Ab or TG Ab, developed TG Ab, while 5 patients from group 2 developed either or both antibodies.The difference between the 2 groups was found not significant (P< 0.1). These findings suggest that introducing moderate dose of iodized oil early in life might have no major ill effect on thyroid immunology as reflected by the production of the main 3 autoantibodies. (Author)

  6. Recalculation of thyroid doses after the Chernobyl accident in a iodine deficient area

    The thyroid doses were estimated in Poland shortly after the Chernobyl accident with assumption of stable iodine consumption for the reference man and areas with ''standard'' stable iodine consumption. These estimates are not representative for southern part of Poland which is known as the iodine deficient area. Therefore the thyroid doses were recalculated based on the real and differentiated stable iodine intakes for people groups of different age without and with thyroid blockade after the accident. (author). 11 refs, 10 figs, 3 tabs

  7. External gamma-irradiation thyroid doses of cohort subjects of radioepidemiological research

    A cumulative external gamma-irradiation thyroid doses are calculated for cohort subjects of the Belarus-American scientific Protocol on studying cancer and other diseases of thyroid in Belarus after Chernobyl accident (1997-2004). Cumulative external g-irradiation thyroid doses are in an interval 0.0069-1434 mGy with a median equal 5.45 mGy. (authors)

  8. Entrance surface dose measurement on the thyroid gland in orthopantomography: The need for optimization

    Background: The anatomic position and proven radiosensitivity of the thyroid make it an organ of concern in dental x-ray examinations. A National Radiation Protection Department sponsored pilot study carried out in the Dental Radiology Department of Rafsanjan University of Medical Sciences, to assess if the radiation dose in panoramic radiographies could be reduced without significant impairment of the subjective image quality. Materials and methods: Thermoluminescent dosimetry is widely acknowledged to be the recommended method for measuring entrance surface doses. In this study, entrance surface doses was measured using LiF thermoluminescent dosimeters (TLD-100) on the thyroid of 40 patients who had referred to the School of Dentistry, Rafsanjan University of Medical Sciences. Patients were no exposed to any additional radiation and the radiographs were used for diagnostic purposes. Thermoluminescent dosimetry were calibrated with radiation energies similar to those commonly used in orthopantomography. Results: The overall mean entrance surface doses on the thyroid in orthopantomography was 0.071±0.012 mGy (ranged from 0.01 to 0.40 mGy). The mean entrance surface doses for radiographies performed with 66 k Vp (20 patients) and 68 k Vp (20 patients) were 0.072± 0.016 respectively. No statistically significant difference was found between these means. Conclusions: The measured surface doses in our study are inconsistent with the only one already reported about the same experiment. However, due to lack of national diagnostic reference levels for orthopantomography, it is not clear whether in case of the Pm 2002 Cc unit used in this experiment, reducing the radiation dose to a level that still keeps a diagnostically acceptable image quality is necessary

  9. Thyroid nodule prevalence and radiation dose from fallout near the Semipalatinsk test site in Kazakhstan

    Thyroid nodule prevalence was use as a biomarker for radiation-related thyroid cancer risk associated with dose from internal and external radiation sources in fallout from the Semipalatinsk Test Site (STS) in Kazakhstan. Ultrasound scans were done on the thyroid glands of 1990 current residents of 7 villages near the STS, all members of a defined study cohort established in the 1960s, and all juveniles at some time during 1949-1962. Questionnaire-guided interviews focused on residential history and childhood consumption of milk and milk products. A refined dose reconstruction algorithm, developed jointly by experts from Russia and the US, was applied to the resulting data to calculate individual estimates of thyroid dose from external and internal sources of fallout-related radiation. Individual radiation dose estimates ranged from zero to 20 Gy for total dose (0-1.7 Gy and 0-20 Gy for dose from external and internal sources, respectively). The ratio of internal to external dose generally increased with increasing distance, reflecting a shift towards smaller particle sizes at greater distances and more effective transfer of small particles through the foodchain. Dose-response analysis was focused on variation of nodule prevalence by sex, age at screening, measured thyroid volume, and reconstructed thyroid dose from external (mainly gamma-ray) and internal (mainly 131I) radiation sources. Nodule prevalence was markedly higher among women and increased significantly with increasing age at screening and with thyroid volume. Highly significant dose responses were observed for nodule prevalence as a function of total thyroid dose and, in a separate analysis, of doses from internal and external sources as distinct independent variables; dose response was linear for total dose 131I cf. x ray with respect to thyroid cancer as an endpoint, based on theoretical, experimental, and epidemiological data

  10. Additive value of pinhole imaging in well differentiated thyroid cancer after surgery

    Park, Soon A.; Lim, Seok Tae; Sohn, Myung Hee [Chonbuk National Univ., Chonju (Korea, Republic of)

    2000-07-01

    It is well known that the image by pinhole collimator (PH) has more good resolution than that by high resolution parallel-hole collimator (HRPH). We performed this study to compare PH and HRPH for the detection of metastatic cervical lymphadenopathy (MCL) from remnant thyroid tissue (RT). One hundred forty three studies in 71 patients (M :F=12: 59, age 43.3{+-}13.9 yrs) were included in our investigation. In 111 of 143 studies which were received 1110 MBq of I-131, HRPH and PH were performed 3 days after intake. PH were obtained with 6 mm aperture in size and for 10 minutes. Markers were placed to the submental and sternal notch region. We compared two image modality for the detection of MCL and RT in cervcal region. All of the patients were revealed well differentiated thyroid cancer (papillary: follicular=68: 3). Sixty five of 111 studies (58.6%) showed concordant results and 46 of 111 (41.4%) showed discordant results. In the group of discordant result, PH study was more useful for the detection of lesions with RT and MCL 25/46 (54.3%) and 29/46 (63%), respectively. In well differentiated thyroid cancer after surgery, we conclude that PH has more useful value in monitoring of therapeutic response in RT, and provides additive information for the necessity of high dose radioactive iodine therapy in patient with MCL.

  11. Comparison of different 131I doses for thyroid remnant ablation in patients with differentiated thyroid carcinoma

    Objective: To compare the ablation efficacy of different 131I doses for thyroid remnant in patients with DTC, and to analyze the factors related to the ablation efficacy. Methods: A total of 343 DTC patients without local or distant metastases post total or near-total thyroidectomy were enrolled into this study. The patients were divided into three groups according to the initial 131I ablation dose: group A included 101 patients with 1850 to 2220 MBq, group B included 103 patients with 2590 to 2960 MBq, group C included 139 patients with 3330 to 3700 MBq. The patients were followed up for 6 to 12 months after initial 131I ablation. Successful ablation was determined according to follow-up 131I whole body scan and TSH stimulated serum Tg levels (<10 μg/L). The χ2 test and logistic regression were performed. Results: The overall successful rate was 63% (215/343). The successful rates in groups A, B and C were 59% (60/101), 64% (66/103) and 64% (89/139), respectively, with no significant difference among three groups (χ2=0.657, P=0.720). Univariant analysis identified that gender (P=0.030), type of surgery (P<0.01), number of the operations (P=0.004), pre-treatment TSH (P=0.019) and pre-treatment Tg (P<0.01) levels were related to the successful ablation rate. Logistic regression identified type of surgery (P<0.01) and pre-treatment Tg (P<0.01) level as the independent predictors for successful ablation. Conclusions: Low dose 131I for thyroid remnant ablation is almost similar to higher dose for DTC patients. However, the type of surgery and pre-treatment TSH stimulated Tg level affect the success rate of 131I ablation. (authors)

  12. Low Dose Gamma Irradiation Potentiates Secondary Exposure to Gamma Rays or Protons in Thyroid Tissue Analogs

    Green, Lora M

    2006-05-25

    We have utilized our unique bioreactor model to produce three-dimensional thyroid tissue analogs that we believe better represent the effects of radiation in vivo than two-dimensional cultures. Our thyroid model has been characterized at multiple levels, including: cell-cell exchanges (bystander), signal transduction, functional changes and modulation of gene expression. We have significant preliminary data on structural, functional, signal transduction and gene expression responses from acute exposures at high doses (50-1000 rads) of gamma, protons and iron (Green et al., 2001a; 2001b; 2002a; 2002b; 2005). More recently, we used our DOE funding (ending Feb 06) to characterize the pattern of radiation modulated gene expression in rat thyroid tissue analogs using low-dose/low-dose rate radiation, plus/minus acute challenge exposures. Findings from these studies show that the low-dose/low-dose rate “priming” exposures to radiation invoked changes in gene expression profiles that varied with dose and time. The thyrocytes transitioned to a “primed” state, so that when the tissue analogs were challenged with an acute exposure to radiation they had a muted response (or an increased resistance) to cytopathological changes relative to “un-primed” cells. We measured dramatic differences in the primed tissue analogs, showing that our original hypothesis was correct: that low dose gamma irradiation will potentiate the repair/adaptation response to a secondary exposure. Implications from these findings are that risk assessments based on classical in vitro tissue culture assays will overestimate risk, and that low dose rate priming results in a reduced response in gene expression to a secondary challenge exposure, which implies that a priming dose provides enhanced protection to thyroid cells grown as tissue analogs. If we can determine that the effects of radiation on our tissue analogs more closely resemble the effects of radiation in vivo, then we can better

  13. Chernobyl accident: revision of individual thyroid dose estimates for the children included in the cohort of the Belarusian-American study

    The observed sharp increase in the number of childhood-thyroid-cancer cases in Belarus that has occurred since the Chernobyl accident stimulated the undertaking in 1994 of a long-term American-Belarusian cohort study. That epidemiological study is aimed at revealing the carcinogenic effectiveness of 131I (the main contributor to the thyroid exposure) and at estimating the risk coefficient of thyroid disease, especially thyroid cancer, as a function of age at exposure. It is planned to follow actively 15,000 children (aged 0-18 at the time of the accident) sampled among about 40,000 who had their thyroid measured in vivo in 1986. Such direct thyroid measurements provide the basis for the initial thyroid dose estimates that have been established for the 40,000 children in the absence of personal interviews. As of August 1999, approximately 5,000 cohort subjects have been screened and interviewed. The initial estimates of individual thyroid dose are being revised for all of the cohort subjects that have been screened. The revision procedure of the 131I thyroid dose assessment consists of two parts: (1) re-analysis of the direct thyroid measurements and (2) analysis of the responses to the personal interview which were conducted in order to determine the kinetics of the radioiodine intake by the cohort subjects. Revised estimates of thyroid dose resulting from 131I intake are presented for a sample of 1,000 subjects residing in various areas of Belarus. The reason for the differences between the initial and the revised thyroid dose estimates are discussed. In addition to the estimation of the internal thyroid dose from 131I, three minor contributors to the thyroid exposure are considered separately: (1) the internal exposure resulting from intake of short-lived radioiodines and radiotelluriums, (2) the internal exposure resulting from intake of other radionuclides (mainly radiocesiums), and (3) external exposure from radionuclides deposited on the ground. Examples are

  14. Thyroid dose estimation with potassium iodide (KI) administration in a nuclear emergency

    In a breach-of-containment nuclear reactor accident, the near-field exposure is primarily through inhalation of radioiodine. Thyroid blockade by oral potassium iodide (KI) is a practical and effective protective measure for the general public in such an emergency. The retention functions incorporating the thyroid blocking effects by KI have been derived using a standard three-compartment model of iodine metabolism. This allows more accurate estimation of the thyroid dose by calculating the blocking factor. (authors)

  15. Effect of vertical angulation to dose of thyroid glands in periapical radiography

    Hosoi, Keitaro; Satoh, Keiji; Furumoto, Keiichi (Nippon Dental Univ., Tokyo (Japan). School of Dentistry)

    1992-10-01

    Much attention has been given to reducing the dose of radiation in dental radiography in terms of the highest risk for the head and neck. Organ doses in intraoral radiography vary greatly with subtle differences in vertical angulation. Quantitative determination of doses delivered to the thyroid gland is thus necessary in determining adequate doses and risk for dental radiography. A personal computer program, prepared for estimating organ doses under various radiographic conditions, was used to evaluate the effect of vertical angulation on the dose delivered to the thyroid gland in radiography of the maxillary and mandibular incisors. Review of the literature revealed that the calculated dose delivered to the thyroid gland is approximately in accordance with the data of the actual determination under the same radiographic conditions. The dose-dependence of radiation delivered to the thyroid gland on vertical angulation of the maxilla was much more than that of the mandible. In the mandible, the dose delivered to the thyroid gland increased about three fold at a field size of 6 cm[phi] and about 1.5 fold at 8 cm[phi] when the vertical angulation changed from -40deg to 0deg. In the maxilla, the delivered dose increased about 480 times at a field size of 6 cm[phi] when vertical angulation changed from 0deg to 50deg and rapidly increased about 280 times at 8 cm[phi] when the angulation changed from 0deg to 40deg. The dose of radiation delivered to the thyroid gland was evaluated as a function of product of the irradiated volume within the primary beam directed at the thyroid gland and the inverse square of the distance between a subject's surface and the thyroid gland. (N.K.).

  16. Thyroid uptake and radiation dose after 131I-lipiodol treatment: is thyroid blocking by potassium iodide necessary?

    In radionuclide therapy with iodine-131 labelled pharmaceuticals, free 131I may be released and trapped by the thyroid, causing an undesirable radiation burden. To prevent this, stable iodide such as potassium iodide (KI) can be given to saturate the thyroid before 131I is administered. The guidelines of the European Association of Nuclear Medicine do not, however, recommend special precautions when administering 131I-lipiodol therapy for hepatocellular carcinoma. Nevertheless, some authors have reported 131I uptake in the thyroid as a consequence of such therapy. In this study, the influence of prophylactic KI on the thyroid uptake and dose (MIRD dosimetry) was prospectively investigated. 131I-lipiodol was given as a slow bolus selectively in the proper hepatic artery or hyperselectively in the right and/or left hepatic artery. Patients were prospectively randomised into two groups. One group received KI in a dose of 100 mg per day starting 2 days before 131I-lipiodol administration and continuing until 2 weeks after therapy (KI group; n=31), while the other group received no KI (non-KI group; n=37). Thyroid uptake was measured scintigraphically as a percentage of administered activity 7 days after 131I-lipiodol (n=68 treatments). The absorbed radiation dose to the thyroid was assessed by scintigraphy after 7 and 14 days using a mono-exponential fitting model and MIRD dosimetry (n=40 treatments). The mean activity of 131I-lipiodol administered was 1,835 MBq in a volume of 2 (n=17) or 4 (n=51) ml. Thyroid uptake was lower in the KI group, being 0.23%±0.06% of injected activity (n=31) compared with 0.42%±0.20% in the non-KI group (n=37); the mean thyroid dose was 5.5±1.6 Gy in the KI group (n=19) versus 11.9±5.9 Gy in the non-KI group (n=21). These differences were statistically significant (P131I-lipiodol administration was evident (P>0.1). 131I-lipiodol is associated with a generally low thyroid uptake and dose that may be significantly decreased by KI

  17. Irradiation doses on thyroid gland during the postoperative irradiation for breast cancer

    Mustafa Akın

    2014-01-01

    Conclusions: In majority of the node-positive breast cancer patients treated with 3D CRT, the thyroid gland was exposed to considerable doses. On the other hand, for 44% of the patients are at risk for developing thyroid function abnormalities which should be considered during the routine follow-up.

  18. Thyroid doses to Belarussian children from the Chernobyl accident: results of an American-Belarussian collaboration

    Full text: The U.S. National Cancer Institute (NCI), in cooperation with the Ministry of Health of Belarus is involved in epidemiological studies of thyroid diseases in children presumably related to the Chernobyl accident. Within the framework of this study, individual thyroid absorbed doses, as well as uncertainties, have been estimated for all members of the cohort (11,918), who were selected from the large group of children aged 0 to 18 whose thyroids were monitored for gamma radiation within a few weeks after the accident. Information on the residence history and dietary habits of each cohort member was obtained during personal interviews. The methodology used to estimate the thyroid absorbed doses resulting from intakes of I 131 by the Belarussian cohort subjects is described. The model of thyroid dose estimation is run in two modes: deterministic and stochastic. In the stochastic mode, the model is run 1,000 times for each subject using a Monte-Carlo procedure. The geometric means of the individual thyroid absorbed doses obtained in the stochastic mode range from 0.0006 to 55 Gy. The arithmetic and geometric means of these individual thyroid absorbed doses over the entire cohort are found to be 1.39 and 0.35 Gy, respectively. On average, the individual thyroid dose estimates obtained in the deterministic mode are about the same as the geometric mean doses obtained in the stochastic mode, while the arithmetic mean thyroid absorbed doses obtained in the stochastic mode are about 25% higher than those obtained in the deterministic mode. The distributions of the 1000 values of the individual thyroid absorbed dose estimates are found to be approximately lognormal, with geometric standard deviations ranging from 1.7 to 4.2 for most cohort subjects. For the time being, only the thyroid doses resulting from intakes of I 131 have been estimated for all subjects. Future work will include the estimation of the contributions to the thyroid doses resulting from external

  19. Absorbed dose by thyroid in case of nuclear accidents; Dose absorvida pela tireoide em casos de acidentes nucleares

    Campos, Laelia; Attie, Marcia Regina Pereira [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Fisica; Lima, Fernando Roberto de Andrade, E-mail: falima@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Amaral, Ademir [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    Radioisotopes of iodine are produced in abundance in nuclear fission reactions, and great amounts of radioiodine may be released into the environment in case of a nuclear reactor accident. Thyroid gland is among the most radiosensitive organs due to its capacity to concentrate iodine. The aim of this work was to evaluate the importance of contributions of internally deposited iodines ({sup 131}I, {sup 132}I, {sup 133}I, {sup 134}I and {sup 135}I) to the dose absorbed to thyroid follicle and to the whole organ, after internal contamination by those isotopes. For internal dose calculation, the code of particles transport MCNP4C was employed. The results showed that, in case of nuclear accidents, the contribution of short-lived iodines for total dose is about 45% for thyroid of newborn and about 40% for thyroid of adult. Thus, these contributions should not be neglected in a prospective evaluation of risks associated to internal contamination by radioactive iodine. (author)

  20. Chernobyl accident. Assessment of the Collective thyroid dose for the Belarusian population

    As a consequence of the Chernobyl accident, a widespread radioactive contamination occurred over the territory of the Republic of Belarus. During the first few weeks after the accident, the intake of 131I, due essentially to the consumption of contaminated milk, resulted in substantial thyroid exposures for many Belarusians. The sharp increase of thyroid cancer cases among children that has been observed since the early 1990s has triggered many studies on the comparison between the levels of thyroid exposure among children and the number of cancer cases. In 1996, we estimated the collective thyroid dose to the Belarusian population to be about 510,000 person Gy (including 130,000 person Gy for the children up to 7 years old at the time of the accident). Since 1996, we have improved the dose assessment model used for 7.3 million residents (73%) of Belarus. Two models will be to assess thyroid doses for rural inhabitants: the first one is based on relationship between mean adult-thyroid dose and the deposition density of 131I or 137Cs in the settlements where lived a sufficient number of residents whose thyroids were measured in vivo in May through beginning of June 1986; the second one is an environmental transfer model making use of the available measurements of 131I in fallout, grass, and milk. For the other 2.7 million residents we will estimate the collective dose based on doses obtained by residents of corresponding settlements or areas, whose thyroids were measured in 1986. The associated uncertainties will be discussed. The magnitude of the collective dose will be compared to the number of observed thyroid cancer cases among children, Oblast by Oblast. The variations observed in various Oblasts of Belarus will be analyzed. (author)

  1. Thyroid doses in Belarus resulting from the Chernobyl accident: comparison of the estimates based on direct thyroid measurements and on measurements of 131I in milk

    A substantial increase of childhood cancer cases observed in Belarus, Ukraine and Russia after the Chernobyl accident has been associated with thyroid exposure to radio iodines following the accident. A large number of direct thyroid measurements (i.e. measurement of the exposure rate near the thyroid of the subject)were conducted in Belarus during a few weeks after the accident. Individual thyroid doses based on results of the direct thyroid measurements were estimated for about 126,000 Belarusian residents and settlement-average thyroid doses for adults were calculated for 426 contaminated settlements in Gomel and Mogilev Oblasts. Another set of settlement-average thyroid doses for adults was estimated based on results of activity measurements in milk samples for 28 settlements (with not less than 2 spectrometric measurements) and 155 settlements (with not less than 5 total beta-activity measurements) in Gomel and Mogilev Oblasts. Concentrations of 131I in milk were derived from these measurements. In the estimation of this set of thyroid doses, it was assumed that adults consumed 0.5 L d-1 of milk locally produced. The two sets of dose estimates were compared for 47 settlements, for which simultaneously were available a dose estimate based on thyroid measurements and a dose estimate based either on spectrometric or radiometric milk data. The settlement average thyroid doses based on milk activity measurements were higher than those based on direct thyroid measurements by a factor of 1.8 for total beta-activity measurements (30 settlements were compared) and by a factor of 2.4 for spectrometric measurements (17 settlements). This systematic difference can be explained by overestimation of the milk consumption rate used in the calculation of the milk-based thyroid doses and/or by application of individual countermeasures by people. (author)

  2. Method for recovery of thyroidal radiation dose due to 131I incorporation

    Method for retrospective recovery of the radiation dose in the thyroid of humans of dirrerent age groups due to 131I incroporation is developed. Method is based on the analysis of density of 137Cs fallout, dose of the mixture of desimented gamma-sources, and the measured adiation dose in the thyroid. The technique is developed using the available data on Chernobyl accident. Ckrrelations were found between the examined parameters in a wide range of the sedimented radionuclides concentrations. The resultant estimated dose dostribution in the thyroid virtually does not differ from that measured in the known settlements. Thyroid radiations doses in similar fallout density of 137Cs and in the same gamma-radiation doses vary by scores; the share of subjects with the maximal radiaiton doses makes up 0.01-0.005%. Highest value of the correlation factor of thyroid radiation dose fallout with the dose of external gamma-radiaiton was found within the risk 8 months after the accident

  3. Reconstruction of radiation doses to the thyroid of children in Belarus suffering from thyroid gland cancer; Rekonstruktion der Schilddruesendosis fuer Kinder mit Schilddruesenkrebs in Weissrussland

    Robl, R.; Voigt, G.; Paretzke, H.G.

    1997-10-01

    About four years after the reactor accident of Chernobyl a pronounced rise in childhood tyroid gland cancer was registered throughout the republic of Belarus. It was soon understood that most likely the short-lived radioiodine isotope {sup 131}I was responsible for this effect. Therefore, methods had to be developed to reconstruct the tyroid dose of those children who suffered from thyroid cancer. To assess the tyroid dose the concentration of {sup 1}31 I in soil was then determined using the assumption of a constant release and transport ratio between {sup 129}I and {sup 131}I. The inferred {sup 131}I-deposition densities on ground were used as input data to a radiological food-chain model and an average integrated tyroid dose to certain age groups of various residence areas were calculated for the main exposure path of milk ingestion. An intercomparison between this new approach and the results of direct thyroid activity measurements was performed. In addition to these two approaches two others were applied for comparison. The first one was based on the generalisation of a correlation between the {sup 137}Cs-deposition density and a few {sup 131}I-measurements. The second approach was based on the determination of {sup 131}I-deposition by an atmospheric dispersion model. It turned out that the values which resulted from the {sup 129}I-method were higher but still closer to those of the direct measurements than the other two approaches. Thyroid doses inferred by the {sup 129}I-method generally ranged between 1 and 100 Sv, depending on the mode of deposition, whereas the values of the direct measurements were found to be in the range of 0.5-5 Sv. The two model approaches applying caesium deposition densities and atmospheric dispersion calculations of radioiodine resulted in lower thyroid exposures ranging between 0.001 and 1.0 Sv only. (orig./MG)

  4. An assessment of thyroid dose of patient and staff performing barium swallow and upper gastrointestinal fluoroscopy examinations

    Introduction: Fluoroscopy is an important diagnostic technique in medicine. Among fluoroscopic procedures barium swallow and upper gastrointestinal account for a large number of examinations. During these procedures. the thyroid of patients is normally irradiated by the primary and scatter ionizing radiation causing both the deterministic and hazardous effects on this tissue. Therefore, the assessment of absorbed doses to the thyroid from these examinations becomes necessary. In addition, to perform these examinations. it is normally required that the radiologists and other radiation workers and paramedics stay in the fluoroscopic room. This puts the clinicians body and their various organs/ tissues, especially their thyroid, under the secondary/ scatter ionizing radiation. This research was carried out to estimate the thyroid absorbed doses of patient and radiation workers involved in fluoroscopic examinations at four different large scale genera hospitals in Tehran. Materials and Methods: To assess the pate int and radiation worker thyroid doses, Li-F thermoluminescent dosimeters were used which are known as thermoluminescent dosimeters -100 and made by Harshaw Company. The thermoluminescent dosimeters cubic chips were first annealed and read out using an appropriate consistent oven to make their background stored counts free. Then, they were exposed to know various amounts of radiation at Karaj Secondary Standard Dosimetry Laboratory of Iran, enabling us to determine a calibration curve for them over the range of exposure common in fluoroscopic procedures. The results of this dose assessment were also compared with those obtained in other countries and with the reference dose levels recommended by some radiation protection organizations. Results: The results indicated an average absorbed dose to the thyroid of patients of 7.89 mGy SE: 1.33) and 2.97 mGy for the barium swallow and upper gastrointestinal fluoroscopic examinations respectively. Corresponding values

  5. Methodology and results of internal dose reconstruction in Russia after the Chernobyl accident. Generic approach and thyroid dose

    Reconstruction of internal dose for various populations has been conducted in Russia following past major environmental radionuclide releases resulting from operation of and emergencies at Mayak PA facility in Urals in 1950s, nuclear weapons tests at Semipalatinsk test site since 1949, and the Chernobyl accident in 1986. The objectives of those activities usually were radiation risk assessment and/or support of radiation and social protection programs and of epidemiological studies. The Russian internal thyroid dose reconstruction program that is the closest to the Fukushima program under development was the Chernobyl study for populations of the more affected areas. Radiation monitoring conducted in the affected areas included measurements of both environmental and food samples and human thyroid. The dose reconstruction procedure for various areas was structured according to availability of monitoring data. The paper presents general methodology for reconstruction of the internal dose in groups of inhabitants of the Chernobyl accident area and practical techniques for reconstruction of the 131I absorbed dose in thyroid. The techniques are based on the results of radiation monitoring performed in 1986 in the Bryansk, Tula, Orel and Kaluga regions of Russia. The 131I measurements of the thyroid as the data most relevant to internal dose are of first priority for dose reconstruction. Radionuclide intake estimation with foods is considered as the second priority and application of radioecological models as the third priority when measurement data are lacking. The developed internal thyroid dose reconstruction algorithms were converted in the official national methodology that was used for large scale reconstruction of average internal thyroid dose in more than four thousand Russian settlements affected by the Chernobyl fallout. The results were used both for decision making regarding radiation and social protection of the public and as support for epidemiological

  6. Dose distribution in the thyroid gland following radiation therapy of breast cancer-a retrospective study

    To relate the development of post-treatment hypothyroidism with the dose distribution within the thyroid gland in breast cancer (BC) patients treated with loco-regional radiotherapy (RT). In two groups of BC patients postoperatively irradiated by computer tomography (CT)-based RT, the individual dose distributions in the thyroid gland were compared with each other; Cases developed post-treatment hypothyroidism after multimodal treatment including 4-field RT technique. Matched patients in Controls remained free for hypothyroidism. Based on each patient's dose volume histogram (DVH) the volume percentages of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual mean thyroid dose over the whole gland (MeanTotGy). The mean and median thyroid dose for the included patients was about 30 Gy, subsequently the total volume of the thyroid gland (VolTotGy) and the absolute volumes (cm3) receiving respectively < 30 Gy and ≥ 30 Gy were calculated (Vol < 30 and Vol ≥ 30) and analyzed. No statistically significant inter-group differences were found between V20, V30, V40 and V50Gy or the median of MeanTotGy. The median VolTotGy in Controls was 2.3 times above VolTotGy in Cases (ρ = 0.003), with large inter-individual variations in both groups. The volume of the thyroid gland receiving < 30 Gy in Controls was almost 2.5 times greater than the comparable figure in Cases. We concluded that in patients with small thyroid glands after loco-radiotherapy of BC, the risk of post-treatment hypothyroidism depends on the volume of the thyroid gland

  7. Assessment of thyroid doses due to 131I from atmospheric nuclear weapons tests in Nevada

    About 100 of the atmospheric nuclear weapons tests carried out at the Nevada Test Site (NTS) resulted in off-site detection of radioactive materials. These tests released about 5 EBq of 131I in the atmosphere, predominantly in 1952, 1953, 1955 and 1957. Radioiodine was deposited across the United States of America, with the highest values immediately downwind of the NTS and the lowest values of the west coast. In the 1980s, three major dose reconstruction studies were undertaken in order to address the assessment of thyroid doses due to 131I fallout from the NTS: (1) the ORERP study of the US Department of Energy; (2) the Utah thyroid cohort study; and (3) the NCI thyroid study. The first two studies are concerned with doses received by 'local' populations (less than 800 km from the NTS), while the third study deals with the estimation of thyroid doses received by populations across the continental USA. In all three studies, uncertainty estimates were attached to the calculated doses. The second and third studies specifically addressed the assessment of thyroid doses from radioiodines, whereas the first study has a much wider scope, in that it considers both external and internal irradiation of the main organs and tissues of the body from all radionuclides produced by nuclear weapons tests. The thyroid doses from NTS fallout resulted essentially from the ingestion of milk contaminated with 131I; other, usually less important, pathways of exposure are the consumption of leafy vegetables and eggs. Because children generally drink more milk than adults, and because of the smaller mass of their thyroid gland, children received higher doses than adults for a given deposition of 131I. The thyroid doses are estimated to have ranged up to a few grays for small children in south-western Utah who drank milk from a family owned goat. A preliminary estimate of the collective thyroid dose to the US population from NTS fallout is 4 x 106 man·Gy, corresponding to a per capita

  8. Estimation of effective dose at thyroid cancer patients treated with I131

    Full text of publication follows. Radioiodine therapy for thyroid cancer patients and hyperthyroid patients at the Institute of Pathophysiology and nuclear medicine is performed in a form of capsules. During the oral application it is reasonable to presume that 15 minutes in stomach is long enough to make additional exposure to stomach as well to other organs nearby. It is almost impossible to perform direct measurements to estimate internal doses of organs, so it is rather recommended to estimate the dose by calculation. Absorbed energy per unit transformation in stomach and surrounding organs has been calculated. The dose equivalents in several internal organs have been calculated in aim to determine the effective doses using appropriate tissue weighting factor values. The MCNP-4b model was used for this calculation. The phantom model was created using three major sections: - an elliptical cylinder representing the trunk and arms - two truncated circular cones representing the legs and feet - a circular cylinder on which sits an elliptical cylinder capped by half an ellipsoid representing the neck and head. The stomach wall is represented by the volume between two concentric ellipsoids and the contents by the volume within the inner ellipsoid. Also TLD measurements were performed over gastric region for limited time of 15 minutes. Estimated effective dose was highest in stomach 7,43*10-02 Sv. The estimated values for other organs like colon, liver, lungs, ovary and bone surface was less than the estimated effective dose of stomach. (authors)

  9. Intercomparison of iodine thyroid doses estimated for people living in urban and rural environments

    The radioecological model ECOSYS, developed in GSF-Institut fuer Strahlenschutz has been applied to calculate thyroid doses to the population due to I-131 exposures after the Chernobyl accident. The main contribution to the thyroid doses calculated is given by the consumption of milk and vegetables. Results are presented taking into account the different activity concentrations measured in milk of private family cows and mixed collective milk of a creamery in upper Bavaria, as well as different consumption behaviour of children and adults in rural and urban areas. Thyroid doses due to different milk consumption habits and a different milk origin in adults living in urban environments are estimated to be up to 12 times, in children up to 3 times lower than those estimated for rural environments. The dose contribution by vegetables, however, in any case exceeded the one by milk because of the high intake rates for the case investigated here. These values, however, may be overestimates for vegetables and have a very high uncertainty. For adults total thyroid dose by ingestion was higher in rural areas by a factor of 1.4, for children at the age of 10 years, total thyroid dose by ingestion was 1.5 times higher in urban environments for the conditions described here. (author)

  10. Development of a method to estimate thyroid dose from fallout radioiodine in a cohort study

    A cohort of 4831 persons aged 11-18 y in 1965 was identified among students in the schools of Washington County, UT; Lincoln County, NV; and Graham County, AZ. These children who had potentially been exposed to radioiodine from atomic weapons test fallout from the Nevada Test Site during 1951-1962 were selected for participation in a study of thyroid disease. The entire cohort was first examined during 1965-1968 for thyroid abnormalities. A total of 3,085 of these people were again reexamined during 1985-1986 to determine any subsequent occurrence of thyroid disease. In order to determine the relationship of the radiation dose to the thyroid with incidence of thyroid disease, we have developed a suite of models to calculate estimates of the internal dose received by the thyroid from fallout radioiodines. For completeness, the exposure to the thyroid from external radiation is also estimated. Dose estimates are made specific to each individual in the study using individual residential histories, the locality-specific exposure rate and radionuclide deposition, descriptions of dairy management for identified milk producers, and the subjects' sources of foods and intake rates of milk and leafy vegetables determined by interview. Other data such as the relationship of radioiodine deposition to measured exposure rate, environmental transfer parameters, and age-dependent factors for the conversion of radioiodine intake to thyroid dose were taken from work of other investigators. Dairy management information, milk distribution practices, the milk source for each study subject, as well as age-specific intake rates of milk and leafy vegetables, were determined by interview

  11. Clinicodiagnostic particularities of microcarcinomas at children who has thyroid cancer in dependence on absorbed doses

    The study showed that microcarcinomas are characterized by long latent development period under comparison with tumors of more than 1 cm. There was marked statistically significant increase of TTG concentration level comparing with low dose at children in high dose group which can be the evidence of possibility of a thyroid functional status decrease during further period of time. (authors)

  12. Thyroid cancer rates and 131I doses from Nevada atmospheric nuclear bomb tests: an update.

    Gilbert, Ethel S; Huang, Lan; Bouville, Andre; Berg, Christine D; Ron, Elaine

    2010-05-01

    Exposure to radioactive iodine ((131)I) from atmospheric nuclear tests conducted in Nevada in the 1950s may have increased thyroid cancer risks. To investigate the long-term effects of this exposure, we analyzed data on thyroid cancer incidence (18,545 cases) from eight Surveillance, Epidemiology, and End Results (SEER) tumor registries for the period 1973-2004. Excess relative risks (ERR) per gray (Gy) for exposure received before age 15 were estimated by relating age-, birth year-, sex- and county-specific thyroid cancer rates to estimates of cumulative dose to the thyroid that take age into account. The estimated ERR per Gy for dose received before 1 year of age was 1.8 [95% confidence interval (CI), 0.5-3.2]. There was no evidence that this estimate declined with follow-up time or that risk increased with dose received at ages 1-15. These results confirm earlier findings based on less extensive data for the period 1973-1994. The lack of a dose response for those exposed at ages 1-15 is inconsistent with studies of children exposed to external radiation or (131)I from the Chernobyl accident, and results need to be interpreted in light of limitations and biases inherent in ecological studies, including the error in doses and case ascertainment resulting from migration. Nevertheless, the study adds support for an increased risk of thyroid cancer due to fallout, although the data are inadequate to quantify it. PMID:20426666

  13. Dose-specific transcriptional responses in thyroid tissue in mice after 131I administration

    Introduction: In the present investigation, microarray analysis was used to monitor transcriptional activity in thyroids in mice 24 h after 131I exposure. The aims of this study were to 1) assess the transcriptional patterns associated with 131I exposure in normal mouse thyroid tissue and 2) propose biomarkers for 131I exposure of the thyroid. Methods: Adult BALB/c nude mice were i.v. injected with 13, 130 or 260 kBq of 131I and killed 24 h after injection (absorbed dose to thyroid: 0.85, 8.5, or 17 Gy). Mock-treated mice were used as controls. Total RNA was extracted from thyroids and processed using the Illumina platform. Results: In total, 497, 546, and 90 transcripts were regulated (fold change ≥ 1.5) in the thyroid after 0.85, 8.5, and 17 Gy, respectively. These were involved in several biological functions, e.g. oxygen access, inflammation and immune response, and apoptosis/anti-apoptosis. Approximately 50% of the involved transcripts at each absorbed dose level were dose-specific, and 18 transcripts were commonly detected at all absorbed dose levels. The Agpat9, Plau, Prf1, and S100a8 gene expression displayed a monotone decrease in regulation with absorbed dose, and further studies need to be performed to evaluate if they may be useful as dose-related biomarkers for 131I exposure. Conclusion: Distinct and substantial differences in gene expression and affected biological functions were detected at the different absorbed dose levels. The transcriptional profiles were specific for the different absorbed dose levels. We propose that the Agpat9, Plau, Prf1, and S100a8 genes might be novel potential absorbed dose-related biomarkers to 131I exposure of thyroid. Advances in knowledge: During the recent years, genomic techniques have been developed; however, they have not been fully utilized in nuclear medicine and radiation biology. We have used RNA microarrays to investigate genome-wide transcriptional regulations in thyroid tissue in mice after low

  14. Normal tissue tolerance to external beam radiation therapy: Thyroid; Dose de tolerance des tissus sains: la thyroide

    Berges, O.; Giraud, P. [Service d' oncologie-radiotherapie, hopital europeen Georges-Pompidou, universite Paris Descartes, 75 - Paris (France); Belkacemi, Y. [Service d' oncologie-radiotherapie, CHU Henri-Mondor, universite Paris 12, 94 - Creteil (France)

    2010-07-15

    The thyroid is the most developed endocrine gland of the body. Due to its anatomical location, it may be exposed to ionizing radiation in external radiotherapy involving head and neck. This review aims to describe the thyroid radiation disorders, probably under-reported in the literature, their risk factors and follow-up procedures. The functional changes after external beam radiation consists mainly of late effects occurring beyond 6 months, and are represented by the clinical and subclinical hypothyroidism. Its incidence is approximately 20 to 30% and it can occur after more than 25 years after radiation exposure. Hyperthyroidism and auto-immune manifestations have been described in a lesser proportion. The morphological changes consist of benign lesions, primarily adenomas, and malignant lesions, the most feared and which incidence is 0.35%. The onset of hypothyroidism depends of the total dose delivered to the gland, and the irradiated. Modern techniques of conformal radiotherapy with modulated intensity could improve the preservation of the thyroid, at the expense of the increase in low doses and the theoretical risk of secondary cancers. (authors)

  15. Using total beta-activity measurements in milk to derive thyroid doses from Chernobyl fallout

    Following the Chernobyl accident, more than 200 childhood thyroid cancer cases have been observed in Brest Oblast of Belarus in territories slightly contaminated with 137Cs, but with suspected relatively high 131I fallout. The most helpful measurements available that can be used to estimate thyroid doses for the population of Brest Oblast are the total beta-activity measurements in cow's milk performed using DP-100 device within a few weeks after the accident. The 131I concentrations in milk were derived from the total beta-activity measurements on the basis of (1) a radioecological model used to estimate the variation with time of the radionuclide composition in milk and (2) the determination of the calibration factors of the DP-100 device for the most important radionuclides present in milk. As a result, 131I concentrations in milk were reconstructed for territories with different levels of 137Cs deposition. A non-linear dependence of the 131I concentration in milk on the 137Cs deposition density was obtained; it was used to estimate the thyroid doses from the consumption of 131I-contaminated cow's milk by the population of Brest Oblast. The average individual thyroid doses have been estimated to be 0.15, 0.18, 0.12, 0.06, 0.04 and 0.03 Gy for newborn, children aged 1, 5, 10 and 15 y and adults, respectively. The collective thyroid dose for the entire population of Brest Oblast is estimated to be 64,500 man Gy, the contribution from the adult population being about one half of the total. The methodology that is described could be applied in the framework of epidemiological studies of the relationship between radiation exposure to the thyroid gland and thyroid cancer in areas where numerous total beta-activity measurements in cow's milk were performed within a few weeks after the accident. (authors)

  16. Thyroid dose of I-131 absorbed by the internal organs of a pregnant woman

    The use of nuclear techniques, for diagnosis or treatment, generates stress in the patient and its relatives. During the pregnancy some sufferings related with the thyroid gland can be presented. If the patient is pregnant, OEP or NOEP, the stress comes from the fear to that the product can it turns affected. The dose is calculated that the Iodine 131, captured by the thyroid of a woman with three months of pregnancy, it deposits in the brain, stomach, heart, kidneys, liver, lungs, ovaries, pancreas, thymus, spleen and in the uterus. The thymus is the organ that receives the biggest dose. (Author)

  17. Estimation of thyroid doses received by the population of Belarus as a result of the Chernobyl accident

    Within weeks of the Chernobyl accident, about 300000 measurements of human thyroidal 131I content were conducted in the more contaminated territories of the Republic of Belarus. Results of these and other measurements form the basis of thyroid-dose reconstruction for residents of Belarus. Preliminary estimates of thyroid doses have been divided into three classes. Class 1 ('measured' doses). Individual doses are estimated directly from the measured thyroidal 131I content of the person considered, plus information on life style and dietary habits. Such estimates are available for about 130000 individuals from the contaminated areas of Gomel and Mogilev Region and Minsk city. Class 2 ('passport' doses). For every settlement with a sufficient number of residents with 'measured' doses, individual thyroid-dose distributions are determined for several age groups and levels of milk consumption. This action has been called the 'passportization' of the settlement. A population of about 2.7 million people resides in the 'passportized' settlements. Class 3 ('inferred' doses). For any settlement where the number of residents with 'measured' doses is small or equal to zero, individual thyroid doses are derived from the relationship obtained between the mean adult-thyroid dose and the deposition density of 131I or 137Cs in settlements with 'passport' doses presenting characteristics similar to those of the settlement considered. This method can be applied to the remainder of the population (about 7.3 million people). An approximate estimate of the collective thyroid dose for the residents of Belarus is presented. Illustrative results of individual thyroid dose and associated uncertainty are discussed for rural settlements and urban areas

  18. Reconstruction of individual doses for the subjects of a case-control study of thyroid cancer in French Polynesia

    A case-control study of thyroid cancer coordinated b y the Unit 605 I.N.S.E.R.M. as carried out in French Polynesia. Forty-six atmospheric nuclear weapons tests (including five safety tests) were conducted in French Polynesia between 966 and 1974. The study includes 600 subjects both cases and controls all aged up to 30 years old at start of nuclear weapons testing. Under the normal conditions following testing the radioactive debris was moved to the east from he test site (atolls Moruroa or Fangataufa) over the uninhabited regions of the Pacific. However, some of the radioactive debris in troposphere was caught in anticyclones eddies and were transferred back to the central South Pacific area in a few days. Radioactive clouds with changed direction result ed in the local deposition of radionuclides on the ground of inhabited islands of French Polynesia. Radiation doses to the thyroids of the subjects were assessed based on the available historical results of radiometric measurements and meteorological data. These included annual reports on the radiological situation in French Polynesia that had been sent to the Secretariat of UNSCEAR. Results of measurements of exposure rate and of total activity in filtered air were used to evaluate the ground depositions of specific radionuclides. Radiation monitoring also included measurements of 131I and 137Cs in cows milk produced in Tahiti and measurements of radioactivity in foodstuffs produced on the selected islands. For each atmospheric nuclear weapons test that contributed substantially to the local deposition of radionuclides, the radiation dose to the thyroid from 131I intake via inhalation and ingestion was estimated. In additional, thyroid doses from the intake of short-lived radio iodines (132, 133, 135 I) and 132Te, external exposure from gamma-emitted radionuclides deposited on the ground, and ingestion of long-lived 137Cs were reconstructed. The assessment of individual thyroid doses took into account: (1) the

  19. Assessment of dose in thyroid and salivary glands in dental radiology using thermoluminescent dosimetry

    Mantuano, Natalia de O.; Silva, Ademir X. da [Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa em Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Canevaro, Luca V.; Mauricio, Claudia Lucia P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ) Rio de Janeiro, RJ (Brazil); Correa, Samanda C.A., E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Radiobiological and epidemiological studies have provided evidence of risk of salivary and thyroid glands tumors incidence associated with oral radiology. Based on these studies, the tissue weighting factors were reviewed by the International Commission on Radiological Protection (ICRP) in 2007. The main objective of the present work is to estimate the absorbed dose on thyroid and salivary glands (parotid, submandibular and sublingual), during a complete periapical examination. The complete periapical examination was simulated using a Spectro 70X Seletronic X-ray dental equipment on an Alderson Rando phantom with Harshaw LiF:Mg,Ti thermoluminescent dosemeters (TLD100). A PTW DIADOS dosimetric system was used for calibration. The TLD100 were inserted into the phantom slices corresponding to the organs of interest. During a complete periapical examination, the highest evaluated mean absorbed dose was 4.9 mGy in the right submandibular gland and the lowest one of 1.5 mGy in the left thyroid lobe. Entrance surface doses ranged from 2.1 to 2.6 mGy, measured, respectively, for the techniques of upper left molar and lower right molar. When compared with the diagnostic reference levels (DRL), the entrance surface doses values were lower than the DRLs recommended in Brazilian current legislation. However, the dosimetric results show the need of optimization for complete periapical examination to minimize patient exposure. Measurements were performed without the use of thyroid protectors. The use of this device is certainly an easy and simple method of dose reduction. (author)

  20. Assessment of dose in thyroid and salivary glands in dental radiology using thermoluminescent dosimetry

    Radiobiological and epidemiological studies have provided evidence of risk of salivary and thyroid glands tumors incidence associated with oral radiology. Based on these studies, the tissue weighting factors were reviewed by the International Commission on Radiological Protection (ICRP) in 2007. The main objective of the present work is to estimate the absorbed dose on thyroid and salivary glands (parotid, submandibular and sublingual), during a complete periapical examination. The complete periapical examination was simulated using a Spectro 70X Seletronic X-ray dental equipment on an Alderson Rando phantom with Harshaw LiF:Mg,Ti thermoluminescent dosemeters (TLD100). A PTW DIADOS dosimetric system was used for calibration. The TLD100 were inserted into the phantom slices corresponding to the organs of interest. During a complete periapical examination, the highest evaluated mean absorbed dose was 4.9 mGy in the right submandibular gland and the lowest one of 1.5 mGy in the left thyroid lobe. Entrance surface doses ranged from 2.1 to 2.6 mGy, measured, respectively, for the techniques of upper left molar and lower right molar. When compared with the diagnostic reference levels (DRL), the entrance surface doses values were lower than the DRLs recommended in Brazilian current legislation. However, the dosimetric results show the need of optimization for complete periapical examination to minimize patient exposure. Measurements were performed without the use of thyroid protectors. The use of this device is certainly an easy and simple method of dose reduction. (author)

  1. A Study on the Effects of Scattering Dose on Eyes and Thyroid for Panoramagraphy

    This study concerning the surface dose of eye and thyroid from panoramagraphy used thermoluminescent dosimeter (TLD) and photoluminescent dosimeter (PLD) to take measurements at ten hospitals in the Gwangju metropolitan area. The recommendations from ICRP 60 and ICRP 73 on the allowance standard for eye are 15 mSv and for thyroid is 1 mSv. The left eye TLD and PLD values are 0.19 mSv and 0.24 mSv respectively. The right eye TLD and PLD values are 0.23 mSv and 0.25 mSv respectively. Thyroid TLD and PLD values are 0.08 mSv and 0.25 mSv respectively and did not exceed the allowance standards(p0.05). The TLD and PLD measured dose from panoramagraphy instruments on eyes and thyroid from each hospital did not exceed the recommended dose from ICRP 60 for surface dose measurements. However, due to the probability of influence, consideration should be made for all levels of dose

  2. Radiation Dose to the Thyroid and Gonads in Patients Undergoing Cardiac CT Angiography

    The present data show a global increase in the rate of cardiovascular disease. Cardiac CT angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. The aim of this study was to measure the radiation dose to the thyroid and pelvis regions in patients undergoing cardiac CT angiography using the Care Dose 4D method of 64-slice scanner. Eighty-one patients (41 males and 40 females) who were diagnosed with suspected coronary artery disease and were referred to Golestan Hospital, Imaging Department were recruited. Inclusion criteria were based on the protocol of multi-slice CT coronary angiography. The radiation dose to the thyroid and pelvis regions was measured using thermo luminescent dosimeters (TLDs). The mean radiation dose to the thyroid in male and female subjects was 0.32 mSv and 0.41 mSv, respectively (P = 0.032) (total mean, 0.36 mSv). The mean radiation dose to the pelvis in male and female subjects was 81 μSv and 112 μSv, respectively (P = 0.026) (total mean, 96.5 μSv), The total mean radiation dose to the thyroid and gonads was 0.36 mSv, and 96.5 μSv, respectively for the subjects. These values were high for one organ in a single study. Gender can affect the radiation dose to the thyroid and gonads. This can be attributed to the anatomical characteristic differences of the male and female subjects

  3. Efficiency of radioiodine therapy with a fix dose of I-131 in toxic thyroid adenoma

    Purpose: The aim of this study was to estimate the results obtained using a fix dose of I-131 in the treatment of the solitary toxic thyroid adenoma. Material and Methods: We have performed radioiodine therapy m 64 patients, 49 female (50+17 yrs) and 15 male (43+-15 yrs) with solitary toxic thyroid adenoma. 45 patients received fix dose I-131 of 850 MBq, while 19 patients were treated with calculated (MBq/gr) dose 555-1100 MBq Previously 39(64%) patients were clinically hyperthyreotic and received thyreostatic meditication which were interruptecf one week before the administration of I-131. Those patients who were euthyreotic, TSH was suppressed(<0.25 MU/m1). 61(95.3%) patients received a single dose, while 3(4, 7%) patients needed two doses. Resulting thyroid matabolism and volume of nodules were evaluated 6-48 months after treatment. Results: From 45 radioiodine treated patients with fix dose 6(9, 8%) became hypothyroidism, 36(85, 3%) euthyroidism and 3(4, 9%) recurrent hyperthyroidism, in comparison with 19 treated patients with calculated I-131 dose: 2(10, 5%) hypothyroidism, 16(84, 3%) euthyroidism and 1(5, 2%) recurrent hyperthyroidism. The size of the nodules became unpalpable m 17(26, 2%), decreased evidently in 33(52, 5%) and remained unchanged in 14(21, 3%) of the treated patients. Conclusion: A fix dose of I-131 is simple, safe and efficient in the treatment of solitary toxic thyroid adenoma. There was not significant different in incidence of late follow-up results of hypothyroidism and recurrent hyperthyroidism between fix dose and calculated MBq/gr dose. (authors)

  4. Alterations of Thyroid Morphology and Function After Long-Term Exposure to Low Doses of Endocrine Disruptor Dichlorodiphenyltrichloroethane

    Yaglov V.V.

    2014-12-01

    Full Text Available The aim of the investigation was to evaluate changes in thyroid morphology and function after different long-term exposure to low doses of endocrine disruptor dichlorodiphenyltrichloroethane (DDT under the maximum permissible levels in food products. Materials and Methods. The experiment was performed on adult male Wistar rats (n=62. Drinking water was substituted for water solution of o,p-DDT 20 and 80 μg/L. Mean daily consumption of DDT was 1.89±0.86 and 7.77±0.17 µg/kg body weight, respectively. Rat serum thyroid hormone content and histology of the thyroid glands were studied after 6 and 10 weeks of exposure to DDT. Results. 6-week exposure to DDT caused inhibition of thyroid function followed by reactive increase of thyroid stimulating hormone secretion and triiodothyronine production. These symptoms were similar to those of the early stage of iodine deficiency. Restoration of rat thyroid status after 10 weeks of exposure was achieved due to diffuse microfollicular transformation of thyroid parenchyma. Conclusion. Exposure to low doses of DDT inhibits thyroid function. Reactive increase of thyroid hormone production after exposure to DDT and in iodine deficiency is similar, but early changes in thyroid histology are different. Long-term exposure to DDT is supposed to aggravate iodine deficiency and to be a risk factor of thyroid tumors.

  5. United States population dose estimates for 131I in the thyroid after the Chinese atmospheric nuclear weapons tests

    Analysis of samples collected within the United States after the Chinese atmospheric nuclear weapons tests of 26 September and 17 November 1976 indicates that the radiation dose to the thyroid from iodine-131 in milk was predominant. A U.S. population dose to the thyroid of 68,000 man-rads was calculated for the iodine-131 fallout. The four excess thyroid cancers that are estimated to occur as a result of the September test during the next 45 years will be masked by the 380,000 cases of thyroid cancer which are expected to occur in the United States from all causes during the same interval

  6. Fetus dose estimation in thyroid cancer post-surgical radioiodine therapy

    Unrecognised pregnancy during radioisotope therapy of thyroid cancer results in hardly definable embryo/fetus exposures, particularly when the thyroid gland is already removed. Sources of such difficulty include uncertainty in data like pregnancy commencing time, amount and distribution of metastasized thyroid cells in body, effect of the thyroidectomy on the fetus dose coefficient etc. Despite all these uncertainties, estimation of the order of the fetus dose in most cases is enough for medical and legal decision-making purposes. A model for adapting the dose coefficients recommended by the well-known methods to the problem of fetus dose assessment in athyrotic patients is proposed. The model defines a correction factor for the problem and ensures that the fetus dose in athyrotic pregnant patients is less than the normal patients. A case of pregnant patient undergone post-surgical therapy by I-131 is then studied for quantitative comparison of the methods. The results draw a range for the fetus dose in athyrotic patients using the derived factor. This reduces the concerns on under- or over-estimation of the embryo/fetus dose and is helpful for personal and/or legal decision-making on abortion. (authors)

  7. Dose distribution in the thyroid and neighboring regions in therapy with 131I

    In this work, simulations were performed with two types of computer simulators: the MIRD phantom and voxel phantom MASH, both of type adult male and in the standing position, coupled to the computational tool GATE (Geant4 Application for Tomographic Emission), to obtain the dose deposited in thyroid and neighboring regions

  8. Thyroid gland morphology in young adults: normal subjects versus those with prior low-dose neck irradiation in childhood

    Thyroid glands obtained at autopsy from young adults were studied to establish more accurately the ''normal'' morphology in the groups 20 to 40 years of age. A total of 56 autopsy specimens (many obtained from trauma victims) were examined in detail by totally embedding and sectioning the thyroid glands. The morphology of these thyroid glands also was compared to that of surgically removed thyroid glands from 47 young adult patients with prior low-dose neck irradiation. The ''normal'' thyroid specimens frequently showed morphologic features, such as thyroid tissue outside the recognizable capsule of the gland (40 of 56 patients) and in the strap muscles of the neck (six of 56 patients), which are conditions commonly considered as evidence for invasive thyroid carcinoma. The thyroid glands from the ''normal'' young adult population were significantly different from those thyroid glands surgically removed from patients who had received irradiation. The irradiated thyroid glands invariably showed multiple nodules of a wide variety of histologic types, extensive lymphocytic infiltrates, and distorting fibrosis as well as a high incidence of malignancy (27 of 47 patients). A single 0.1 cm focus of papillary carcinoma was found in one specimen in the nonirradiated thyroid group. This study suggests that ''occult'' thyroid carcinomas in the group 20 to 40 years of age are rare and are significantly fewer in number than in the older population (P less than 0.02)

  9. Decreased uptake of therapeutic doses of iodine-131 after 185-MBq iodine-131 diagnostic imaging for thyroid remnants in differentiated thyroid carcinoma

    We performed a prospective random study to assess possible thyroid stunning by a 185-MBq iodine-131 dose used to diagnose thyroid remnants. Patients with differentiated thyroid carcinoma were included after total or near-total thyroidectomy. They were randomly assigned to two groups. In group 0 (G0, 32 patients), iodine-123 administration only was used to diagnose thyroid remnants and/or metastasis, so that no thyroid stunning by 131I would occur. In group 1 (G1, 19 patients), diagnostic imaging was performed with 123I and 185 MBq 131I. 123I imaging was less sensitive than 131I imaging in identifying thyroid remnants in both groups (94%). Thyroid uptake of 123I was measured in both groups (at 2 h) and was not significantly different between the groups. Patients with thyroid remnants who remained in the study (28/32 in G0, 17/19 in G1) were treated with 370 MBq 131I, 5 weeks after treatment (mean time, range 12-84 days). In 12/17 G1 patients thyroid uptake measurement was repeated immediately before treatment. Uptake was equal to 1.97%±0.71% and significantly lower (P131I decreases thyroid uptake for several weeks after administration and can impair immediate subsequent 131I therapy; (2) 123I is slightly less sensitive than 131I in identifying thyroid remnants; and (3) the need to scan for thyroid remnants remains to be confirmed, since only 2/51 patients enrolled in this study were not treated with 131I. (orig.)

  10. Molecular alterations in childhood thyroid cancer after Chernobyl accident and low-dose radiation risk

    The linear no-threshold (LNT) model of radiation carcinogenesis has been used for evaluating the risk from radiation exposure. While the epidemiological studies have supported the LNT model at doses above 100 mGy, more uncertainties are still existed in the LNT model at low doses below 100 mGy. Thus, it is urged to clarify the molecular mechanisms underlying radiation carcinogenesis. After the Chernobyl accident in 1986, significant amount of childhood thyroid cancer has emerged in the children living in the contaminated area. As the incidence of sporadic childhood thyroid cancer is very low, it is quite evident that those cancer cases have been induced by radiation exposure caused mainly by the intake of contaminated foods, such as milk. Because genetic alterations in childhood thyroid cancers have extensively been studied, it should provide a unique chance to understand the molecular mechanisms of radiation carcinogenesis. In a current review, molecular signatures obtained from the molecular studies of childhood thyroid cancer after Chernobyl accident have been overviewed, and new roles of radiation exposure in thyroid carcinogenesis will be discussed. (author)

  11. Metastasis survey with a high dose of I-131 May Stun the thyroid

    This paper reports that up to 10 mCi of I-131 has been advocated as a scanning dose to help select patients for I-131 thyroablation after total thyroidectomy for differentiated thyroid cancers. A study was conducted to determine if such doses could stun the thyroid cells and if the same phenomenon occurred with I-123. The diagnostic scans and their corresponding therapy scans were visually compared in 33 patients. If the thyroid activity in the therapy scan (after 100-200 mCi) was less than in the diagnostic scan, the thyroid was considered stunned. Twenty-six patients received I-131 (3-10 mCi) and seven received I-123 (300 μCi). Stunning occurred in two of the five patients given 3 mCi, two of the three given 5 mCi, and 16 of the 18 given 10 mCi of I-131, and in one of the seven patients given I-123 (P = .0007). Fifteen of the 24 remnants compared with one of 11 distant metastases were stunned (P = .004). Seven of the 13 patients with stunned thyroid function showed unsuccessful ablation

  12. Radiation Dose in the Thyroid and the Thyroid Cancer Risk Attributable to CT Scans for Pediatric Patients in One General Hospital of China

    Yin-Ping Su

    2014-03-01

    Full Text Available Objective: To quantify the radiation dose in the thyroid attributable to different CT scans and to estimate the thyroid cancer risk in pediatric patients. Methods: The information about pediatric patients who underwent CT scans was abstracted from the radiology information system in one general hospital between 1 January 2012 and 31 December 2012. The radiation doses were calculated using the ImPACT Patient Dosimetry Calculator and the lifetime attributable risk (LAR of thyroid cancer incidence was estimated based on the National Academies Biologic Effects of Ionizing Radiation VII model. Results: The subjects comprised 922 children, 68% were males, and received 971 CT scans. The range of typical radiation dose to the thyroid was estimated to be 0.61–0.92 mGy for paranasal sinus CT scans, 1.10–2.45 mGy for head CT scans, and 2.63–5.76 mGy for chest CT scans. The LAR of thyroid cancer were as follows: for head CT, 1.1 per 100,000 for boys and 8.7 per 100,000 for girls; for paranasal sinus CT scans, 0.4 per 100,000 for boys and 2.7 per 100,000 for girls; for chest CT scans, 2.2 per 100,000 for boys and 14.2 per 100,000 for girls. The risk of thyroid cancer was substantially higher for girls than for the boys, and from chest CT scans was higher than that from head or paransal sinus CT scans. Conclusions: Chest CT scans caused higher thyroid dose and the LAR of thyroid cancer incidence, compared with paransal sinus or head CT scans. Therefore, physicians should pay more attention to protect the thyroid when children underwent CT scans, especially chest CT scans.

  13. Dose and risk evaluation to the thyroid gland in intra-oral dental radiology

    Intra-oral technique is one of the most frequently used procedures of dental radiology, allowing the detection of a variety of dental anomalies such as caries, dental trauma and periodontal lesions, while exposing patients to relatively low doses of radiation. However, although the adverse effects of doses generated by dental radiology are essentially stochastic, a number of epidemiological studies have provided evidence of an increased risk of thyroid tumors for dental radiography. Many studies have measured doses of radiation for dental radiography, but only a few have estimated thyroid dose. Furthermore, most of the studies on dose evaluation in dental radiology are based on standardized calculation phantoms, which neglect the variance of the patient size or even sex. The purpose of this study is to use the Monte Carlo code MCNPX and the FAX (Female Adult voXel) and MAX (Male Adult voXel) phantoms to investigate how absorbed doses to the thyroid gland in intraoral dental examinations vary in female and male patients. The lifetime cancer incidence attributable to dental examinations were estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The phantoms study proved a useful trial for detecting the radiation dose to the thyroid gland and conclusively supported that the anatomy may be regarded as an influencing factor in radiation dose received during dental examination. Finally, the results have also confirmed that the association of the MCNPX code and the MAX and FAX phantoms is very useful in dosimetric studies on radiographic examinations of female and male patients. (author)

  14. Dose and risk evaluation to the thyroid gland in intra-oral dental radiology

    Intra-oral technique is one of the most frequently used procedures of dental radiology, allowing the detection of a variety of dental anomalies such as caries, dental trauma and periodontal lesions, while exposing patients to relatively low doses of radiation. However, although the adverse effects of doses generated by dental radiology are essentially stochastic, a number of epidemiological studies have provided evidence of an increased risk of thyroid tumors for dental radiography. Many studies have measured doses of radiation for dental radiography, but only a few have estimated thyroid dose. Furthermore, most of the studies on dose evaluation in dental radiology are based on standardized calculation phantoms, which neglect the variance of the patient size or even sex. The purpose of this study is to use the Monte Carlo code MCNPX and the FAX (Female Adult voXel) and MAX (Male Adult voXel) phantoms to investigate how absorbed doses to the thyroid gland in intra-oral dental examinations vary in female and male patients. The lifetime cancer incidence attributable to dental examinations were estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The phantoms study proved a useful trial for detecting the radiation dose to the thyroid gland and conclusively supported that the anatomy may be regarded as an influencing factor in radiation dose received during dental examination. Finally, the results have also confirmed that the association of the MCNPX code and the MAX and FAX phantoms is very useful in dosimetric studies on radiographic examinations of female and male patients. (author)

  15. Radiation Dose to the Thyroid and Gonads in Patients Undergoing Cardiac CT Angiography

    Behroozi, Hamid; Davoodi, Mohammad; Aghasi, Shahriar

    2015-01-01

    Background: The present data show a global increase in the rate of cardiovascular disease. Cardiac CT angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. Objectives: The aim of this study was to measure the radiation dose to the thyroid and pelvis regions in patients undergoing cardiac CT angiography using the Care Dose 4D method of 64-slice scanner. Patients and Methods: Eighty-one patients (41 males an...

  16. Measurement of the thyroid's iodine absorption utilizing minimal /sup 131/I dose

    Paz A, B.; Villegas A, J.; Delgado B, C. (Universidad Nacional San Agustin de Arequipa (Peru). Departamento de Bioquimica)

    1981-03-01

    We utilize a minimal dose of /sup 131/I thus limiting the contact of the thyroid tissues with the isotopic materials to determine the absorption of /sup 131/I by the thyroid from 6 to 24 hours in 90 pupils of the locality of Arequipa. The average rate of absorption in 6 and 24 hours in the case considered are of 24.15% and 35.42% respectively, with a standard deviation of 6.93% and 9.61%. No significant differences were reported from the results of those of adults and our own results in all the probes which were undertaken.

  17. Optimization of the therapeutic dose of {sup 131}I for thyroid differentiated carcinoma; Otimizacao da dose terapeutica com {sup 131}I para carcinoma diferenciado da tiroide

    Lima, Fabiana Farias de

    2002-09-01

    I-131 thyroid cancer therapy is based on the strategy of concentrating radioactive iodine in the thyroid tissue, to completetly eliminate thyroid tissue and functioning thyroid cancer metastases remaining after thyroidectomy. In Brazil, fixed activities of {sup 131} I generally are given, sometimes either delivering insufficient activities to ablate all of the remnants, or unnecessarily high activities, with patients remaining in the hospital for some period of time. This investigation proposes a protocol of individualized planning of ablative doses, based on individual patients metabolisms and measured thyroid remnant masses. Simulated thyroid remnants were fabricated in various forms, volumes and activities, and optimum image acquisition parameters were determined using Single-Photon Emission Computed Tomography 9SPECT). Resultant images were evaluated, to determine the apparent volumes and the {sup 131} I concentrations. I-131 metabolism was studied in 9 patients who had undergone thyroidectomies. Their thyroid remnant masses were determined applying the same parameters used in SPECT simulation studies, and the optimum activity for their therapy was calculated and compared to the established fixed activity of 3.7 GBq (100 mCi), which would have normally been assigned. Background subtraction using the method of percent maximum counts, using a value of 67.5%, combined with scatter correction (triple energy window method), was shown to be optimum for SPECT quantification of volumes between 3-10 ml. Errors in the method were below 9% for sources with regular geometries and around 11% for sources with irregular geometries. In the patient studies, it was observed that 78% of patients could have received reduced activities of {sup 131} (from 0.8-3-2. GBq (20-87 nCi). In addition, 33% of these patients could have received low enough activities to have discharged from the hospital, using an individualized administration scheme. This could also have resulted in a dose

  18. Thyroid nodules in the population living around semipalatinsk nuclear test site. Possible implications for dose-response relationships study

    The risk of radiation-induced nodules is higher than the risk for radiation-induced cancer. Risk factors and specific modifiers of the dose-response relationship may vary among different populations and not be well recognized. Many thyroid studies have considered thyroid nodularity itself, but not specific morphological types of thyroid nodules. There are many specific types of thyroid nodules which follow a morphological classification of thyroid lesions, including some congenital and tumor-like conditions. Modern equipment and technique can help us to identify particular specific types of thyroid nodules. In this study we report some results of a clinically applicable approach to materials derived from three studies. From 1999 through 2002, we have screened 571 current residents from 4 exposed and 1 control village near the Semipalatinsk Nuclear Test Site area, who were of similar ages (<20) at the time of major radiation fallout events at the Semipalatinsk Nuclear Test Site (SNTS). Prevalent nodules were identified by ultrasound and fine-needle aspiration biopsy, cytopathology results. Analysis of ultrasound images and cytopathology of thyroid lesions among exposed and non-exposed population allowed us to distinguish some interesting ultrasound features for specific types of thyroid nodules. We believe that it would be interesting and possibly more informative for thyroid dosimetry studies to consider specific morphological types of thyroid nodules. We need more detailed research to clarify the feasibility of applying these findings for study of the dose-response relationship. (author)

  19. Effects of different doses of iodine on 99TcmO4- uptake of thyroid in mice

    Objective Thyroid is the important endocrine organ in human body. If the function of thyroid is hurt, the basal metabolism will be disorded. The thyroid radionuclide imaging of thyroid plays an important role in the diagnosis and treatment of thyroid. The aim of this study was to observe the effect of different levels of iodine on thyroid uptake of 99TcmO4- in mice. Methods: 288 Kunming mice were divided into 8 groups at completely random. One was control group fed with running water, the others were high iodine groups fed with water containing different KIO3 concentration, i.e. 50, 100, 150, 200, 250, 500, 5000 μg/L. After fed 7 days, the mice was injected 99TcmO4- 3.7 MBq/L (0.1 mCi),t hen the thyroid weight and thyroid uptake of 99TcmO4- in mice were measured at 10 min, 20 min, 25 min. 30 min, 45 min, 60 min. Results: There was a negative correlationship between the iodine dose and the 99TcmO4- radioactive uptake of thyroid. The thyroid uptake of 99TcmO4- in the groups that the KIO3 concentration is 150 μg/L or above was significantly different from that control group at different times (P 99TcmO4- uptake was depressed in the thyroid of mice. (authors)

  20. Proposal for dose measurement in the crystalline lens and thyroid in computerized tomography of paranasal sinuses

    With the evolution of diagnostic imaging equipment, a computerized tomography (CT) has become one of the most used tests to assess pathologies affecting the paranasal sinuses. This work aims at presenting a method of obtaining measurements of dose in the eye lenses and thyroid, from the execution of CT of the paranasal sinuses protocol. Experimental procedure will be used in an object simulator (phantom) head and neck made with accessible materials and thermoluminescent dosimeters (TLDs) of LiF: Mg,Ti for the absorbed dose in the regions of interest, when exposed to radiation in a CT scanner 16 channels. After the dosimetric evaluation with phantom use, this methodology will be applied in vivo, or in patients with medical request for the examination and approval by the Ethics Committee. Thus, at the end of this survey protocols and actions aimed at reducing the absorbed dose in the eye lenses and thyroid without impairing the diagnostic image quality can be proposed. (author)

  1. Predictive estimate of blood dose from external counting data preceding radioiodine therapy for thyroid cancer

    Bone marrow depression following 131I therapy for metastatic thyroid cancer can occur in up to one-quarter of all patients so treated. An analysis was made of the 131I whole body (WB) retention and its relationship to activity in blood for 46 patients (45 adult, 1 adolescent in 49 total studies) to define the accuracy of utilizing WB external counting data as a predictor of blood dose in comparison to the more classical method which requires data from sequential blood samples. The mean percentage differences between blood dose estimates based on external WB counting and those calculated by the classical method lie within ± 10%. The WB methodology provides a useful first-order approximation for hematopietic dose estimates in adult patients undergoing 131I therapy for thyroid cancer. (author)

  2. Internal thyroid doses to Fukushima residents-estimation and issues remaining.

    Kim, Eunjoo; Kurihara, Osamu; Kunishima, Naoaki; Momose, Takumaro; Ishikawa, Tetsuo; Akashi, Makoto

    2016-08-01

    Enormous quantities of radionuclides were released into the environment following the disastrous accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011. It is of great importance to determine the exposure doses received by the populations living in the radiologically affected areas; however, there has been significant difficulty in estimating the internal thyroid dose received through the intake of short-lived radionuclides (mainly, (131)I), because of the lack of early measurements on people. An estimation by the National Institute of Radiological Sciences for 1 April 2012 to 31 March 2013 was thus performed using a combination of the following three sources: thyroid measurement data ((131)I) for 1080 children examined in the screening campaign, whole-body counter measurement data ((134)Cs, (137)Cs) for 3000 adults, and atmospheric transport dispersion model simulations. In this study, the residents of Futaba town, Iitate village and Iwaki city were shown to have the highest thyroid equivalent dose, and their doses were estimated to be mostly below 30 mSv. However, this result involved a lot of uncertainties and provided only representative values for the residents. The present paper outlines a more recent dose estimation and preliminary analyses of personal behavior data used in the new method. PMID:27538842

  3. Neck ultrasonography as preoperative localization of primary hyperparathyroidism with an additional role of detecting thyroid malignancy

    Kwon, Joon Ho; Kim, Eun-Kyung [Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Lee, Hye Sun [Biostatistics Collaboration Unit, Medical Research Center, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Moon, Hee Jung [Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kwak, Jin Young, E-mail: docjin@yuhs.ac [Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of)

    2013-01-15

    Objective: To evaluate and compare the diagnostic performances of high-resolution ultrasonography and {sup 99m}Tc-sestamibi scintigraphy for the preoperative localization of abnormal parathyroid glands and to evaluate the ability of US for additional diagnostic roles in detecting thyroid malignancy in patients with pHPT. Materials and methods: Preoperative localization images of 115 parathyroid adenomas from high-resolution ultrasonography (US) and {sup 99m}Tc-sestamibi scintigraphy (SS) were studied from 105 patients, who had undergone parathyroidectomy. Sensitivity, accuracy, and positive predictive value were calculated for the identification of adenomas in lesions and patients for both US and SS, respectively, and US and SS diagnostic performances were compared using generalized estimating equation. Results: Preoperative imaging by both modalities localized 105 (93.8%) of the 112 parathyroid lesions confirmed at surgery and histology. Sensitivity, accuracy, and positive predictive value were 93.1% and 92.2%, 90.4% and 89.5%, and 96.9% and 96.9% by US and SS, respectively, without any statistically significant differences (P = 0.796, 0.796, 0.879). US found incidental thyroid nodules in 47 patients (47/107, 43.9%), and 7 patients (7/107, 6.5%) were confirmed to have malignancy based on pathology results (all had papillary thyroid carcinoma). Conclusion: Neck ultrasonography and {sup 99m}Tc-sestamibi scintigraphy are complementary methods of the preoperative localization of parathyroid adenomas. Neck ultrasounds add an additional thyroid gland evaluation, and can be useful in the detection of incidental thyroid gland lesions, especially malignant nodules.

  4. I-131 therapy for thyroid diseases: Doses, new regulations and patient advice

    I-131 therapy has been widely used in the past 50 years. Its main applications are hyperthyroidism and functioning thyroid cancer. The indications, doses, regulations, precautions and guidelines differ in various centers. The following are recommended: 1. I-131 should be indicated in agreement of the endocrinologist and the nuclear physician with the patient consent; 2. Pre-treatment I-131 thyroid uptake must be performed; 3. The only contraindication for treatment is pregnancy, in children it might be used with caution; 4. For thyrotoxicosis both a calculated or an ablative dose (555 MBq) criteria are acceptable In this case secondary hypothyroidism must be considered an objective rather than a complication; 5. In uninodular toxic goiter a 1110 MBq dose is recommended; 6. Iodine free diet is indicated only for cancer patients; 7. Propylthiouracil (PTU) must be discontinued 5 days before treatment, it should be reinitiated 5 days later; 8. Prophylactic use of corticoid in Graves' disease still require more clinical data to support its use; 9. In treatment failure, wait six months for a new dose; 10. In intrathyroid cancer disease an ablative dose of 3700 MBq should be administered 4 weeks post-thyroidectomy or with a TSH level above 30 μUI/mL; 11. A whole body scan should be done one week later; 12. Follow-up whole body scan should be used only if there is clinical suspicion of metastasis. Thyroid hormone replacement must be discontinued for 30 days or with TSH value above 30 I/mL. For follow-up scan 185 MBq of I-131 are recommended to ovoid thyroid tissue stunning; 13. For metastases, 5700 to 7400 MBq dose is recommended if there are cervical lymphatic nodes or distant metastases. We recommended to adopt the criteria proposed by the United States Nuclear Regulatory Commission (NRC) published as 10 CFR 35.75 and the Regulatory Guide 8.39 for patients release after I-131 administration. (author)

  5. The thyroid dose assessments of Belarus population by iodine 131 after the Chernobyl accident derived with method of radioecological modeling

    During the Chernobyl accident large activities of iodine were released (more than 1850 GBq). The most important radioiodine isotope was I-131, its deposition varied from from 0.2 to 37 MBq/m2 in five from six Belarus districts. Therefore, in the first few months, the thyroid was the most exposed organ. The correct information on a large group people needs for the thyroid dose estimation and risk assessment. The radioecological model was applied to estimate age-dependence thyroid doses for the Belarus population. The average thyroid doses were calculated for 0-18 age group and adults for 23 thousand 325 settlements of all Belarus areas and Gomel and Minsk cities. The maximum values of thyroid dose were estimated for the inhabitants of the Gomel area and city. The average thyroid dose for the Mogilev area is similar to Brest area. In the Mogilev area, there was predominantly wet deposition leading to a relatively higher initial contamination of the plant, whereas in the Brest area, the deposition was mixed. The estimates for Grodno and Minsk areas are very similar. The lowest thyroid doses were derived for Vitebsk area with the lowest level of depositions (author)

  6. Marginal iodide deficiency and thyroid function: Dose-response analysis for quantitative pharmacokinetic modeling

    Severe iodine deficiency (ID) results in adverse health outcomes and remains a benchmark for understanding the effects of developmental hypothyroidism. The implications of marginal ID, however, remain less well known. The current study examined the relationship between graded levels of ID in rats and serum thyroid hormones, thyroid iodine content, and urinary iodide excretion. The goals of this study were to provide parametric and dose-response information for development of a quantitative model of the thyroid axis. Female Long Evans rats were fed casein-based diets containing varying iodine (I) concentrations for 8 weeks. Diets were created by adding 975, 200, 125, 25, or 0 μg/kg I to the base diet (∼25 μg I/kg chow) to produce 5 nominal I levels, ranging from excess (basal + added I, Treatment 1: 1000 μg I/kg chow) to deficient (Treatment 5: 25 μg I/kg chow). Food intake and body weight were monitored throughout and on 2 consecutive days each week over the 8-week exposure period, animals were placed in metabolism cages to capture urine. Food, water intake, and body weight gain did not differ among treatment groups. Serum T4 was dose-dependently reduced relative to Treatment 1 with significant declines (19 and 48%) at the two lowest I groups, and no significant changes in serum T3 or TSH were detected. Increases in thyroid weight and decreases in thyroidal and urinary iodide content were observed as a function of decreasing I in the diet. Data were compared with predictions from a recently published biologically based dose-response (BBDR) model for ID. Relative to model predictions, female Long Evans rats under the conditions of this study appeared more resilient to low I intake. These results challenge existing models and provide essential information for development of quantitative BBDR models for ID during pregnancy and lactation.

  7. The Effect of High Dose Radioiodine Therapy on Formation of Radiation Retinopathy During Thyroid Cancer Treatment

    Tülay Kaçar Güvel

    2014-10-01

    Full Text Available 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.

  8. [Technic of fine needle aspiration cytology of the thyroid gland: coagulation inhibiting and stabilizing additives].

    Schröder, F; Poley, F

    1988-04-01

    In the fine needle aspiration cytology of the thyroid gland by the moistening of cannule and syringe with heparin or citric sodium rather disadvantages for the evaluation are the result. Artificial changes are most clearly to be seen in heparin. ACD-buffer does indeed not bring about any artefacts, does, however, also not show any provable advantages. In the fine needle biopsy the additives mentioned are entirely avoidable. PMID:3388921

  9. Radiation dose to family members of hyperthyroidism and thyroid cancer patients treated with 131I

    The thermoluminescence dosemeter (TLD) was used for measuring radiation dose to family members of thyrotoxicosis and thyroid cancer patients treated with 131I using CaSO4:Dy discs. There were 45 family members of thyrotoxicosis patients, who were divided into two groups with 22 in the first and 23 in the second group. Radiation safety instructions were the same for both the groups except in the second group where the patients were advised to use a separate bed at home for the first 3 d of dose administration. An activity ranging from 185 to 500 MBq was administered to these patients. The whole-body dose to family members ranged from 0.4 to 2.4 mSv (mean 1.1 mSv) in the first group and 0-1.9 mSv (mean 0.6 mSv) in the second group. A total of 297 family members of thyroid cancer patients were studied for whole-body dose estimation. An activity ranging from 0.925 to 7.4 GBq was administered to the thyroid cancer patients. The family members were divided into three groups depending upon the mode of transport and facilities available at home to avoid close proximity with the patient. Group A with 25 family members received a dose ranging from 0 to 0.9 mSv (mean 0.4 mSv), group B with 96 family members received a dose ranging from 0 to 8.5 mSv (mean 0.8 mSv) and group C with 176 family members received a dose ranging from 0 to 5.0 mSv (mean 0.8 mSv). The thyroid monitoring was also done in 103 family members who attended the patients in isolation wards for >2 d. Thyroid dose in them ranged from 0 to 2.5 mGy (mean 0.1 mGy). (authors)

  10. Age- and sex-dependent model for estimating radioiodine dose to a normal thyroid

    This paper describes the derivation of an age- and sex-dependent model of radioiodine dosimetry in the thyroid and the application of the model to estimating the thyroid dose for each of 4215 patients who were exposed to 131I in diagnostic and therapeutic procedures. The model was made to conform to these data requirements by the use of age-specific estimates of the biological half-time of iodine in the thyroid and an age- and sex-dependent representation of the mass of the thyroid. Also, it was assumed that the thyroid burden was maximum 24 hours after administration (the 131I dose is not critically sensitive to this assumption). The metabolic model is of the form A(t) = K[exp(-μ1t) - exp(-μ2t)] (μCi), where μ1 = lambda/sub r/ + lambda/sub i//sup b/ (i = 1, 2), lambda/sub r/ is the radiological decay-rate coefficient, and lambda/sub i//sup b/ are biological removal rate coefficients. The values of lambda/sub i//sup b/ are determined by solving a nonlinear equation that depends on assumptions about the time of maximum uptake and the eventual biological loss rate (through which age dependence enters). The value of K may then be calculated from knowledge of the uptake at a particular time. The dosimetric S-factor (rad/μCi-day) is based on specific absorbed fractions for photons of energy ranging from 0.01 to 4.0 MeV for thyroid masses from 1.29 to 19.6 g; the functional form of the S-factor also involves the thyroid mass explicitly, through which the dependence on age and sex enters. An analysis of sensitivity of the model to uncertainties in the thyroid mass and the biological removal rate for several age groups is reported. The model could prove useful in the dosimetry of very short-lived radioiodines. Tables of age- and sex-dependent coefficients are provided to enable readers to make their own calculations. 12 refs., 5 figs., 4 tabs

  11. Comparison of skin absorbed radiation dose in thyroid gland area during panoramic radiography and spiral tomography techniques

    Najmeh Akhlaghi

    2011-01-01

    Full Text Available Introduction: Thyroid gland is one of the critical organs during radiation in the head and neck region. The aim of this study was to compare absorbed radiation dose by skin in the thyroid area during spiral tomography and panoramic radiography by means of thermoluminance dosimetry (TLD.Materials and Methods: Thirty-six LiF (TLD-100 thermoluminescence dosimetry chips were utilized in this experimental in vitro study. One TLD chip was placed on the tube side and another was placed on the opposite side of the thyroid gland of a sliced anatomic Alderson head and neck phantom during panoramic radiography and spiral tomography. The dosimeters were read by a SOLARO 2A TLD reader twice followed by calculation of the absorbed dose. The results were analyzed by Wilcoxon’s test at a confidence interval of 95%.Results: The mean dose for screen-film panoramic radiographs was 34 µGy in the left thyroid and 39 on the right side. With spiral tomography the thyroid gland received a mean dose of 30‒71 µGy. There were no statistically significant differences in the mean thyroid doses between anterior and posterior spiral tomography and panoramic examination (p value > 0.05.Conclusion: Skin absorbed radiation dose of a tomographic examination, which includes four sections with a specific thickness, are almost comparable to that with a panoramic radiographic technique. Key words: Absorbed dose, Spiral tomography, Panoramic radiography.

  12. Comparison of therapeutic efficacy and clinical parameters between recombinant human thyroid stimulating hormone and thyroid hormone withdrawal in high-dose radioiodine treatment with differentiated thyroid cancer

    High-dose radioiodine treatment (HD-RIT) after injection of recombinant human thyroid stimulating hormone (rh-TSH) has become widely used. This study compared the therapeutic efficacy of HD-RIT and clinical parameters between rh-TSH supplement and thyroid hormone withdrawal (THW) after total thyroidectomy in patients with differentiated thyroid cancer. We retrospectively reviewed 266 patients (47 male and 219 female; age, 49.0 ± 10.9 years) with differentiated thyroid cancer detected from September 2011 to September 2012. Patients comprised THW (217, 81.6 %) and rh-TSH (49, 18.4 %). Inclusion criteria were: first HD-RIT; any TN stage; absence of distant metastasis. To evaluate the complete ablation of the remnant thyroid tissue or metastasis, we reviewed stimulated serum thyroglobulin (sTg), I-123 whole-body scan (RxWBS) on T4 off-state, and thyroid ultrasonography (US) or [F-18]-fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) 6–8 months after HD-RIT. We defined a complete ablation state when all three of the follow-up conditions were satisfied; <2.0 ng/ml of the sTg, I-123 RxWBS (−), and thyroid US or F-18 FDG PET/CT (−). If one of the three was positive, ablation was considered incomplete. We also compared various clinical biomarkers (body weight, body mass index, liver and kidney function) between THW and rh-TSH groups. The rates of complete ablation were 73.7 % (160/217) for the THW group and 73.5 % (36/49) for the rh-TSH group. There was no significant difference between the two groups (p = 0.970). The follow-up aspartate transaminase (p = 0.001) and alanine transaminase (p = 0.001) were significantly higher in the THW group. The renal function parameters of blood urea nitrogen (p = 0.001) and creatinine (p = 0.005) tended to increase in the THW group. The change of body weight was + Δ0.96 (±1.9) kg for the THW group and was decreased by -Δ1.39 (±1.5) kg for the rh-TSH group. The change

  13. Comparison of therapeutic efficacy and clinical parameters between recombinant human thyroid stimulating hormone and thyroid hormone withdrawal in high-dose radioiodine treatment with differentiated thyroid cancer

    Choi, Se Hun; Na, Chang Ju; Kim, Jeong Hun; Han, Yeon Hee; KIm, Hee Kwon; Jeong, Hwan Jeong; Sohn, Myung Hee; Lim, Seok Tae [Dept. of Nuclear Medicine, Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of)

    2015-06-15

    High-dose radioiodine treatment (HD-RIT) after injection of recombinant human thyroid stimulating hormone (rh-TSH) has become widely used. This study compared the therapeutic efficacy of HD-RIT and clinical parameters between rh-TSH supplement and thyroid hormone withdrawal (THW) after total thyroidectomy in patients with differentiated thyroid cancer. We retrospectively reviewed 266 patients (47 male and 219 female; age, 49.0 ± 10.9 years) with differentiated thyroid cancer detected from September 2011 to September 2012. Patients comprised THW (217, 81.6 %) and rh-TSH (49, 18.4 %). Inclusion criteria were: first HD-RIT; any TN stage; absence of distant metastasis. To evaluate the complete ablation of the remnant thyroid tissue or metastasis, we reviewed stimulated serum thyroglobulin (sTg), I-123 whole-body scan (RxWBS) on T4 off-state, and thyroid ultrasonography (US) or [F-18]-fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) 6–8 months after HD-RIT. We defined a complete ablation state when all three of the follow-up conditions were satisfied; <2.0 ng/ml of the sTg, I-123 RxWBS (−), and thyroid US or F-18 FDG PET/CT (−). If one of the three was positive, ablation was considered incomplete. We also compared various clinical biomarkers (body weight, body mass index, liver and kidney function) between THW and rh-TSH groups. The rates of complete ablation were 73.7 % (160/217) for the THW group and 73.5 % (36/49) for the rh-TSH group. There was no significant difference between the two groups (p = 0.970). The follow-up aspartate transaminase (p = 0.001) and alanine transaminase (p = 0.001) were significantly higher in the THW group. The renal function parameters of blood urea nitrogen (p = 0.001) and creatinine (p = 0.005) tended to increase in the THW group. The change of body weight was + Δ0.96 (±1.9) kg for the THW group and was decreased by -Δ1.39 (±1.5) kg for the rh-TSH group. The change

  14. Age- and sex-dependent model for estimating radioiodine dose to a normal thyroid

    This paper describes the derivation of an age- and sex-dependent model of radioiodine dosimetry in the thyroid and the application of the model to estimating the thyroid dose for each of 4215 patients who were exposed to 131I in diagnostic and therapeutic procedures. In most cases, the available data consisted of the patient's age at the time of administration, the patient's sex, the quantity of activity administered, the clinically-determined uptake of radioiodine by the thyroid, and the time after administration at which the uptake was determined. The metabolic model is of the form A(t) = K[exp(-μ1t) -exp(-μ2t)] (μCi), where μ1 = λ/sub r/ - λ/sub i//sup b/ (i = 1, 2), λ/sub r/ is the radiological decay-rate coefficient, and λ/sub i//sup b/ are biological removal rate coefficients. The values of λ/sub i//sup b/ are determined by solving a nonlinear equation that depends on assumptions about the time or maximum uptake an the eventual biological loss rate (through which age dependence enters). The value of K may then be calculated from knowledge of the uptakes at a particular time. The dosimetric S-factor (rad/μCi-day) is based on specific absorbed fractions for photons of energy ranging from 0.01 to 4.0 MeV for thyroid masses from 1.29 to 19.6 g; the functional form of the S-factor also involves the thyroid mass explicitly, through which the dependence on age and sex enters. An analysis of sensitivity of the model to uncertainties in the thyroid mass and the biological removal rate for several age groups is reported. 12 references, 5 figures, 5 tables

  15. Influence of age and mode of radioiodine exposure on thyroidal radiologic dose

    In assessing the age-related variability in thyroidal radiation dose following exposure to ingested and inhaled radioiodine, available data on milk consumption and respiration, and data on iodine metabolism for humans or derived from animal studies have been utilized to estimate thyroidal doses following acute exposures to 131I, 132I and 133I. Age groups considered include adults, fetuses in the 13th, 20th and 32nd weeks of gestation, neonates, 1-yr-old infants, and 5-, 10-, and 15-yr-old children. The more susceptible members of the population to raioiodine exposure, are determined. From ingested 131I, fetuses were calculated to receive 0.1, 3, and 7 times the adult dose in the 13th, 20th and 32nd weeks of gestation, respectively. Newborns were calculated to receive 4 times the adult value, while 1-yr-old infants would receive the highest relative dose, over 12 times that of adults. Five-, 10-, and 15-yr-old children were estimated to receive about 5, 3 and 2 times the adult dose respectively. From inhaled radioiodines, the relative doses can be ranged 132I>133I>131I. Relative to adults, doses to fetuses at the 3 respective ages were up to 0.6, 7, and 10 times greater. Doses to neonates and infants were determined to be 4 and 2 times the adult dose, respectively, while doses to children were less than 30% more than those to adults. These results indicate that from equivalent exposures to radioiodines, there are differing doses to the thyroid glands of various members of population, reflecting metabolic differences. Furthermore, the age-related changes vary with the mode of exposure. From ingested 131I, the infant appears to receive the greatest radiation dose, calculated to be 12 times the adult dose, while the near-term fetus would receive about 7 times the adult value. Following inhalation, on the other hand, the fetus was calculated to receive up to 10 times the adult dose, and the infant, only about twice the adult value

  16. Dose concepts and dosimetry for radioiodine therapy of benign thyroid diseases

    Dose planning prior to radioiodine therapy of benign thyroidal disease is usually based on macrodosimetry. The paper shows that this assumption is acceptable. The common concepts for dose planning are given. The following target doses are nowadays widely accepted: 150 Gy for euthyroid goiter, 400 Gy for toxic adenoma, 150 Gy for disserminated autonomy, 200 Gy for hyperthyroid Grave's disease if posttherapeutic euthyroidism is intended, and 250 (to 300) Gy if the risk of recurrency is to be minimized ('ablative' concept). Finally, a surveyfis given concerning the precision in which the parameters relevant for the dose calcultion can be determined. For realistic favourable conditions, the dose can be determined with an accuracy of better than ±25%. (orig.)

  17. Thyroid cancer

    The role of ionizing radiation in the introduction of thyroid carcinoma is discussed. In the treatment of thyroid cancer, radioiodine administration is of value as an ablation procedure, completing the thyroidectomy and as a method to irradiate selectively functioning thyroid carcinoma tissue that cannnot be removed surgically. Results of the clinical management of 155 patients with malignant thyroid tumours are presented. The ablation dose of iodine-131 can be decreased to 40 millicuries thus effectively reducing the patients whole body radiation dose

  18. Pregnancy after high therapeutic doses of iodine-131 in differentiated thyroid cancer: potential risks and recommendations

    Seventy female patients who had been treated with high doses of iodine-131 for differented thyroid cancer (DTC) and who had a subsequent pregnancy were evaluated. The global 131I dose ranged from 1.85 to 16.55 GBq (mean±SD=4.39±25.20 GBq). Age at first therapy ranged from 15 to 36 years (mean±SD=24.3±5.0 years) and the interval from 131I therapy to pregnancy varied from 2 to 10 years (mean±SD=5.3±2.8 years). The estimated radiation dose to the gonads ranged from 10 to 63 cGy (mean±SD=24.0±13.5 cGy). All patients were treated with L-thyroxine at doses capable of suppressing thyroid-stimulating hormone. Seventy-three children were followed-up and seven pregnancies are still in progress. One child was affected by Fallot's trilogy and three had a low birth weight though with subsequent regular growth; the others were healthy with subsequent regular growth. No newborn with clinical or biochemical thyroid dysfunctions was found. Two spontaneous abortions during the second month of pregnancy were recorded. One of two patients in question subsequently had two healthy children. On the basis of these data, previous administration of high 131I doses does not appear to be a valid reason for dissuading young female DTC patients from considering pregnancy. However, patients should be advised to avoid pregnancy after 131I administration for a period sufficient to ensure complete elimination of the radionuclide and to permit confirmation of complete disease remission, i.e. at least 1 year in our opinion. (orig.)

  19. Thyroid absorbed dose for people at Rongelap, Utirik, and Sifo on March 1, 1954

    A study was undertaken to reexamine thyroid absorbed dose estimates for people accidentally exposed to fallout at Rongelap, Sifo, and Utirik Islands from the Pacific weapon test known as Operation Castle BRAVO. The study included: (1) reevaluation of radiochemical analysis, to relate results from pooled urine to intake, retention, and excretion functions; (2) analysis of neutron-irradiation studies of archival soil samples, to estimate areal activities of the iodine isotopes; (3) analysis of source term, weather data, and meteorological functions used in predicting atmospheric diffusion and fallout deposition, to estimate airborne concentrations of the iodine isotopes; and (4) reevaluation of radioactive fallout, which contaminated a Japanese fishing vessel in the vicinity of Rongelap Island on March 1, 1954, to determine fallout components. The conclusions of the acute exposure study were that the population mean thyroid absorbed doses were 21 gray (2100 rad) at Rongelap, 6.7 gray (670 rad) at Sifo, and 2.8 gray (280 rad) at Utirik. The overall thyroid cancer risk we estimated was in agreement with results published on the Japanese exposed at Nagasaki and Hiroshima. We now postulate that the major route for intake of fallout was by direct ingestion of food prepared and consumed outdoors. 66 refs., 13 figs., 25 tabs

  20. Thyroid absorbed dose for people at Rongelap, Utirik, and Sifo on March 1, 1954

    Lessard, E.T.; Miltenberger, R.P.; Conrad, R.A.; Musoline, S.V.; Naidu, J.R.; Moorthy, A.; Schopfer, C.J.

    1985-03-01

    A study was undertaken to reexamine thyroid absorbed dose estimates for people accidentally exposed to fallout at Rongelap, Sifo, and Utirik Islands from the Pacific weapon test known as Operation Castle BRAVO. The study included: (1) reevaluation of radiochemical analysis, to relate results from pooled urine to intake, retention, and excretion functions; (2) analysis of neutron-irradiation studies of archival soil samples, to estimate areal activities of the iodine isotopes; (3) analysis of source term, weather data, and meteorological functions used in predicting atmospheric diffusion and fallout deposition, to estimate airborne concentrations of the iodine isotopes; and (4) reevaluation of radioactive fallout, which contaminated a Japanese fishing vessel in the vicinity of Rongelap Island on March 1, 1954, to determine fallout components. The conclusions of the acute exposure study were that the population mean thyroid absorbed doses were 21 gray (2100 rad) at Rongelap, 6.7 gray (670 rad) at Sifo, and 2.8 gray (280 rad) at Utirik. The overall thyroid cancer risk we estimated was in agreement with results published on the Japanese exposed at Nagasaki and Hiroshima. We now postulate that the major route for intake of fallout was by direct ingestion of food prepared and consumed outdoors. 66 refs., 13 figs., 25 tabs.

  1. Hormones of thyroid gland in sera of rats treated with different dose of concentrated potassium iodine solutions

    Marković Ljiljana

    2010-01-01

    Full Text Available Introduction Potassium iodine (KI is used as a drug therapy for treating numerous diseases such as small-vessel vasculitis, erythema nodosum, vasculitis nodularis, Sweet's syndrome, tuberculosis and granulomatosis, and for iodized salt. At the same time, KI can be harmful. Iodine intake may increase the frequency of thyroiditis in humans, and may induce the occurrence of experimental thyroiditis (ET in animals. Investigations on an experimental model for the examination of thyroiditis in Wistar rats have clearly showed morphological changes in the rat thyroid evoked by KI administration. Objective The purpose of this study was to compare the effects of low and high doses of KI on the thyroid gland of Wistar rats and determine the effect on hormone status (T4, T3 and TSH in this rat strain. Methods Two groups of rats from the Wistar strain were treated with a low iodine dose (225 μg/g BW and with a high iodine dose (675 μg/g BW of KI solutions. Untreated nonimmunized animals served as controls. The solution was administrated daily intraperitoneally during the period of 26 consecutive days. Results Monitoring hormone status (TSH, T3 and T4 and morphological changes it was found that therapeutic doses of KI applied in treatment induced the occurrence of experimental thyroiditis (chronic destructive Hashimoto's thyroiditis in humans and cell necrosis in animals not carrying a genetic susceptibility. Significant inflammatory changes were observed in rats treated with a high iodine dose. Conclusion The early iodine induced cell necrosis and inflammation in the nonimmunized animals without genetic susceptibility is a new experimental model of thyroiditis. .

  2. The usefulness of Al face block fabrication for reducing exposure dose of thyroid glands in mammography

    Hong, Eun Ae [Dept. of Diagnostic Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of); Lee, In Ja [Dept. of Radiologic Technology, Dongnam Health College, Suwon (Korea, Republic of)

    2013-03-15

    Currently, there are many studies being conducted around the world to reduce exposure dose to radiation for patients to receive medical treatments in a safe environment. We developed and fabricated of this shield that the patients are protected from the radiation and are need of safety control during breast imaging. In this study, for breast imaging, GE Senography 2000D were used and set at SID 65 cm, 28 kVp, and 63 mAs. The measuring instrument was Flukes Victoreen 6000-529. And we performed Face Block on with 30 patients. The chamber on the actual thyroid glands to take CC and MLO and measure the dosage before and after wearing the Face Block. For the results, after wearing the Face Block, exposure was decreased by 53.8%-100% and 65.8% in average in CC View and by 50%-100% and 60.7% in average in MLO View. The development of the Face Block that practically decreased the exposure dose of thyroid glands, crystalline eyes during breast imaging and reduced the patients anxiety during breast imaging. The Face Block is expected to improve patients satisfaction and contribute to reducing patients exposure dose, but more efforts should be made to reduce exposure dose to medical radiation.

  3. Influence of Lake Trophic Structure on Iodine-131 Accumulation and Subsequent Cumulative Radiation Dose to Trout Thyroids

    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. - Highlights: • 131I introduced into lakes is concentrated through food webs. • Highest concentrations in trout thyroids are from 8 to 32 days after release. • Continuing high concentrations causes linearly increasing cumulative doses. • The majority of the dose to thyroids is due to beta emissions. • Cumulative doses at 32 days may be >6 mGy g−1 per initial 131I mBq mL−1

  4. Efficacy of low-dose iodine-131 ablation of post-operative thyroid remnants: a study of 69 cases

    Low-dose iodine-131 of mean activity 1117 MBq was used to ablate post-operative thyroid remnants in 69 patients with differentiated thyroid cancer. Successful ablation was defined as uptake of less than 1% at 48 h and absence of visible image on the post-ablation scan. Ablation by one dose was successful in 95% of patients after total or subtotal thyroidectomy, and 56% of patients after partial or hemithyroidectomy. All patients with uptake of 10% or less on the pre-ablation scan had successful ablation. The results are compared with other reports using low-dose radioiodine ablation and the significance of the findings discussed. (Author)

  5. Salivary gland protection by amifostine in high-dose radioiodine therapy of differentiated thyroid cancer

    Quantitative salivary gland scintigraphy using 100 to 120 MBq Tc-99m-pertechnetate was performed in 17 patients with differentiated thyroid cancer prior to and 3 months after radioiodine treatment with 6 GBq I-131. Eight patients were treated with 500 mg/m2 amifostine prior to high-dose radioiodine treatment and compared retrospectively with 9 control patients. Xerostomia was graded according to WHO criteria. In 9 control patients high-dose radioiodine treatment significantly (p<0.01) reduced Tc-99m-pertechnetate uptake by 35.4±22.0% and 31.7±21.1% in parotid and submandibular glands, respectively. Of these 9 patients, 3 exhibited xerostomia Grade I (WHO). In contrast, in 8 amifostine-treated patients, there was no significant (p=0.878) decrease in parenchymal function following high-dose radioiodine treatment, and xerostomia did not occur in any of them. (orig.)

  6. Prognosis of thyroid doses in case of a maximum design basis accident at a nuclear power plant

    The aim of this study was to make prognosis of thyroid doses in case of an accident at a nuclear power plant. In order to achieve this, the following was done: - assessment of thyroid doses formed due to maximum design basis accident (MDBA) at NPP with pressurized water reactor (at different distances from the station); - estimation of the length of the territories at which dose exposure may exceed the current international generic criteria for protective and other actions in case of a nuclear emergency. Various scenarios of possible weather conditions were considered in order to simulate the transfer of radionuclides in the atmosphere. This study allowed estimating the thyroid doses, as well as the necessity of protective and other actions in case of the MDBA. Results of prognosis using the international models have demonstrated that: - thyroid doses due to inhalation of iodine-131 don't exceed 2 mGy, due to consumption of contaminated milk - 40 mGy, vegetables - 5 mGy; - there is no need in thyroid blocking for population; The results of modeling performed in this study form a basis for developing national arrangements for response to a MDBA at considered NPP. (authors)

  7. Thyroid equivalent doses due to radioiodine-131 intake for evacuees from Fukushima Daiichi Nuclear Power Plant accident

    A primary health concern among residents and evacuees in affected areas immediately after a nuclear accident is the internal exposure of the thyroid to radioiodine, particularly I-131, and subsequent thyroid cancer risk. In Japan, the natural disasters of the earthquake and tsunami in March 2011 destroyed an important function of the Fukushima Daiichi Nuclear Power Plant (F1-NPP) and a large amount of radioactive material was released to the environment. Here we report for the first time extensive measurements of the exposure to I-131 revealing I-131 activity in the thyroid of 46 out of the 62 residents and evacuees measured. The median thyroid equivalent dose was estimated to be 4.2 mSv and 3.5 mSv for children and adults, respectively, much smaller than the mean thyroid dose in the Chernobyl accident (490 mSv in evacuees). Maximum thyroid doses for children and adults were 23 mSv and 33 mSv, respectively. (author)

  8. Value of basal TSH and free T3 in detecting thyroid disorders as compared to additional T4 parameters

    Data of 411 untreated patients undergoing thyroid investigations were stored in a data base system. Three combinations of thyroidal hormone parameters were compared with respect to their clinical value. In patients with concordant basal TSH (bTSH) and free T3(fT3)-values (e.g. bTSH normal and fT3 normal, bTSH decreased and fT3 increased) it could be demonstrated that the predictive value of the combined evaluation of basal TSH (supersensitive) and free T3 alone (97% in normal thyroid function, 98% in thyrotoxicosis, and 97% in hypothyroidism) was sufficient. Additional determinations of T4 parameters did not increase predictive value (e.g. TT4: 95% in thyrotoxicosis). Thus, thyroid disorders may currently be diagnosed by the combined evaluation of basal TSH and free T3, saving costs without loss of diagnostic efficacy. (orig.)

  9. Usefulness of recombinant human TSH aided radioiodine doses administered in patients with differentiated thyroid carcinoma

    The published studies confirming the safety and efficacy of rh TSH for diagnostic purposes have led to an increased interest in its use for preparation for radioiodine (RI) dose administration in patients with recurrent or persistent differentiated thyroid carcinoma (DTC). In order to establish the efficacy of RI therapy after rh TSH, we have reviewed 39 rh TSH-aided radioiodine treatments in a series of 28 DTC patients. Patients were divided into two groups: GI (n=17), with previous thyroid bed uptake and undetectable thyroglobulin (Tg) levels under levothyroxine treatment and GII (n=11), with proven metastatic local or distant disease. Median follow-up after the first rh TSH-aided radioiodine treatment was 32 ± 13 months (range 8 to 54 months). Sixteen patients (94%) in GI were rendered disease free and one patient was shown to have persistent disease. In GII, the post therapy whole body scan showed pathological uptakes in all cases: in four patients in lungs, in four in mediastinum and in three in lateral neck. In two patients with mediastinum uptake, Tg levels were undetectable after rh TSH. In the follow-up, two patients with lateral neck uptake were rendered disease free, four patients died (three due to thyroid cancer) and five out of the remaining patients have persistent disease. In conclusion, rh TSH aided therapy was helpful to eliminate normal thyroid bed remnants in 16/17 (94%) patients (GI). rh TSH stimulated Tg was undetectable in two patients with mediastinal metastasis. We believe that rh TSH is a good alternative to levothyroxine withdrawal for the treatment of DTC with radioactive iodine, increasing the quality of life in these patients. Caution should be recommended in the follow-up of unselected DTC patients only with stimulated Tg levels. (author)

  10. Application of Monte Carlo method for dose calculation in thyroid follicle

    The Monte Carlo method is an important tool to simulate radioactive particles interaction with biologic medium. The principal advantage of the method when compared with deterministic methods is the ability to simulate a complex geometry. Several computational codes use the Monte Carlo method to simulate the particles transport and they have the capacity to simulate energy deposition in models of organs and/or tissues, as well models of cells of human body. Thus, the calculation of the absorbed dose to thyroid's follicles (compound of colloid and follicles' cells) have a fundamental importance to dosimetry, because these cells are radiosensitive due to ionizing radiation exposition, in particular, exposition due to radioisotopes of iodine, because a great amount of radioiodine may be released into the environment in case of a nuclear accidents. In this case, the goal of this work was use the code of particles transport MNCP4C to calculate absorbed doses in models of thyroid's follicles, for Auger electrons, internal conversion electrons and beta particles, by iodine-131 and short-lived iodines (131, 132, 133, 134 e 135), with diameters varying from 30 to 500 μm. The results obtained from simulation with the MCNP4C code shown an average percentage of the 25% of total absorbed dose by colloid to iodine- 131 and 75% to short-lived iodine's. For follicular cells, this percentage was of 13% to iodine-131 and 87% to short-lived iodine's. The contributions from particles with low energies, like Auger and internal conversion electrons should not be neglected, to assessment the absorbed dose in cellular level. Agglomerative hierarchical clustering was used to compare doses obtained by codes MCNP4C, EPOTRAN, EGS4 and by deterministic methods. (author)

  11. Retrospective estimation of contamination with short-lived nuclides of belarus territory and modeling of doses to the thyroid gland of population after accident at the Chernobyl NPP

    Observed in Belarus a growth of thyroid pathology in population attracted attention of the specialists to the problem of reconstruction of radiation situation and doses from short-lived radionuclides particularly iodine isotopes. However, available data regarding radiation situation and obtained dose estimates to thyroid could not explain this fact. (authors)

  12. Calculation of thyroid doses with milk consumption after the Chernobyl accident

    Internal irradiation dose build-up when using milk as a food is considered taking as an example 131 I fallout in Obninsk (Kaluga region). The technique for estimation of human thyroid internal irradiation dose caused by 131 I intake into the organism over the chain including atmospheric fallout-grass-cow-milk under conditions of milk animals grazing during contamination period and under condition of consumption only the locally produced milk is suggested. The curves characterizing maximum dose build-up with time, as well as the picture of 131 I accumulation with time in grass and in soil for comparison are given. It is shown that internal dose accumulated as a result of fallout before June, 1 and September, 1 under the conditions of milk animals grazing during the whole period of grass contamination with 131 I deviates slightly and amounts to 0.084 and 0.085 cSv respectively. The main contribution ≅ 99% is given by the dose connected with fallout before June, 1, the contributions of those before May, 5 and May, 1 are 80% and 40% correspondingly

  13. Estimate of dose in crystalline and thyroid in exam complete periapical

    The constant achievement of dental radiography portrays the necessity of care in this practice for neither patient nor professional subject to a risk of excessive radiation. The main aim of this work is to estimate the crystalline and thyroid absorbed dose, during dental radiography. To evaluate the dose distribution it was used thermoluminescent dosimeter T.L.D.100. The measures were carried out on patients during intra-oral dental radiography in some dental clinics in Rio de Janeiro. Three dental equipments were investigated: Dhabi ATLANTE 1070, DABI ATLANTE 70x and SELETRONIC 70x. Analyzing the doses evaluated, it can be observed that there is a variation in the obtained values for the three points studied and for the three equipments utilized. It was noticed that while using the DABI1070, a larger dose was taken because of the size field diameter to equipment. In the 70x equipment was that one what obtains best results in every points. The results obtained from the SELETRONIC 70x have shown that there is a difference in two techniques used: with the positioner or without it. This achieved values superior than that, because the tip of patient was on display straight to radiation. This study was useful to confirm the excessive dose, besides of not was biased to nothing for the radiography quality,represents a risk for the patient who retains unnecessary and harmful radiation to system. (authors)

  14. Estimate of dose in crystalline and thyroid in exam complete periapical

    Bonzoumet, S.P.J.; Braz, D. [Lab. de Instrumentacao Nuclear, COPPE/UFRJ, CEP, Rio de Janeiro (Brazil); Barroso, R.C. [Rio de Janeiro Univ. do Estado, Instituto de Fisica (Brazil); Mauricio, C.L.P.; Domingues, C. [Instituto de Radioprotecao e Dosimetria IRD / CNEN (Brazil); Padilha, L.G.F. [Rio de Janeiro Univ. Federal, Hospital Universitario (Brazil)

    2006-07-01

    The constant achievement of dental radiography portrays the necessity of care in this practice for neither patient nor professional subject to a risk of excessive radiation. The main aim of this work is to estimate the crystalline and thyroid absorbed dose, during dental radiography. To evaluate the dose distribution it was used thermoluminescent dosimeter T.L.D.100. The measures were carried out on patients during intra-oral dental radiography in some dental clinics in Rio de Janeiro. Three dental equipments were investigated: Dhabi ATLANTE 1070, DABI ATLANTE 70x and SELETRONIC 70x. Analyzing the doses evaluated, it can be observed that there is a variation in the obtained values for the three points studied and for the three equipments utilized. It was noticed that while using the DABI1070, a larger dose was taken because of the size field diameter to equipment. In the 70x equipment was that one what obtains best results in every points. The results obtained from the SELETRONIC 70x have shown that there is a difference in two techniques used: with the positioner or without it. This achieved values superior than that, because the tip of patient was on display straight to radiation. This study was useful to confirm the excessive dose, besides of not was biased to nothing for the radiography quality,represents a risk for the patient who retains unnecessary and harmful radiation to system. (authors)

  15. External dose measurements for patients receiving therapeutic I-131 for thyroid cancer

    Iodine-131 is a well established and effective treatment, supplementing surgery, in differentiated thyroid carcinoma. Iodine-131 except from its β-emission, that generates a cell-killing effect in a small area, has also a γ-emission irradiating distant tissues and even people who are close enough with the treated patient. The International Commission on Radiation Protection, ICRP has estimated the probability of a radiation-induced fatal cancer for the whole population at 5.0 % per sievert for low doses and at low dose rates and at 1.3 % for serious genetic diseases. For elderly people the probability seems to be 3 to 10 times lower, whereas for children up to the age of 10 years, 2-3 times higher. These findings led the ICRP to recommend new dose limits, lower than the previous ones. The European Union has endorsed the ICRP recommendations and the Council issued two directives, with which the Greek legislation complied recently. The current annual public dose limit is 1 mSv, while in the new Greek legislation the concept of dose constrains (0.5 m Sv in Greece) has also been proposed as a goal to reach whenever possible

  16. Action of different doses of 131I on thyroid gland, its tissue distribution and elimination in adult male rats

    Adult male Wistar rats were administered 4, 37, 74 or 185 MBq/kg 131I i.p. Activities were measured in the thyroid gland or region, blood plasma (total and protein bound), salivary glands, cerebral cortex, skin, liver, spleen, small intestine, kidney, heart and skeletal muscle after 1-30 (36) days. Beginning 8 days after radiothyroidectomy the remaining or possibly regenerated thyroid function was tested with a test dose of 185 kBq/kg i.p. After administration of 4 MBq/kg 131I the thyroid gland showed a regeneration within 30 days, but not after treatment with higher doses. The time course of tissue distribution of activity is dose dependent: after 4 MBq/kg 131I increasing activities after the 3rd-8th day are observed in skin, brain, salivary glands, intestine, spleen, kidney, heart and skeletal muscle. After 37 MBq/kg 131I only in skin, brain, liver and intestine increasing activities between the 8th and 30th day have been observed. After 185 MBq/kg 131I only in skin, spleen and intestine increasing activities after the 15th day were measured. Thyroid gland activity 24 hs after administration of 185 kBq/kg 131I showed during the experimental period of 50 days considerable variation with a factor of 4 for thyroid gland, 8 for protein-bound and about 10 for total plasma 131I activity. (author)

  17. Transcriptional Response in Mouse Thyroid Tissue after 211At Administration: Effects of Absorbed Dose, Initial Dose-Rate and Time after Administration.

    Nils Rudqvist

    Full Text Available 211At-labeled radiopharmaceuticals are potentially useful for tumor therapy. However, a limitation has been the preferential accumulation of released 211At in the thyroid gland, which is a critical organ for such therapy. The aim of this study was to determine the effect of absorbed dose, dose-rate, and time after 211At exposure on genome-wide transcriptional expression in mouse thyroid gland.BALB/c mice were i.v. injected with 1.7, 7.5 or 100 kBq 211At. Animals injected with 1.7 kBq were killed after 1, 6, or 168 h with mean thyroid absorbed doses of 0.023, 0.32, and 1.8 Gy, respectively. Animals injected with 7.5 and 100 kBq were killed after 6 and 1 h, respectively; mean thyroid absorbed dose was 1.4 Gy. Total RNA was extracted from pooled thyroids and the Illumina RNA microarray platform was used to determine mRNA levels. Differentially expressed transcripts and enriched GO terms were determined with adjusted p-value 1.5, and p-value <0.05, respectively.In total, 1232 differentially expressed transcripts were detected after 211At administration, demonstrating a profound effect on gene regulation. The number of regulated transcripts increased with higher initial dose-rate/absorbed dose at 1 or 6 h. However, the number of regulated transcripts decreased with mean absorbed dose/time after 1.7 kBq 211At administration. Furthermore, similar regulation profiles were seen for groups administered 1.7 kBq. Interestingly, few previously proposed radiation responsive genes were detected in the present study. Regulation of immunological processes were prevalent at 1, 6, and 168 h after 1.7 kBq administration (0.023, 0.32, 1.8 Gy.

  18. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-01-01

    Abstract The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36–6.23) and 1.00 (0.67–1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident. PMID:27583855

  19. Thyroid cancer

    This paper reviews the relationship between A-bomb radiation and thyroid cancer in the literature. The previous studies have showed a similar outcome; that is, the incidence of thyroid cancer is higher with increasing radiation doses. Risk for thyroid cancer is significantly high in women. Latent cancer found at autopsy is also found to be significantly increased with increasing radiation doses, especially for women. (N.K.)

  20. Time-integrated thyroid dose for accidental releases from Pakistan Research Reactor-1

    The two-hourly time-integrated thyroid dose due to radio-iodines released to the atmosphere through the exhaust stack of Pakistan Research Reactor-1 (PARR-1), under accident conditions, has been calculated. A computer program, PAKRAD (which was developed under an IAEA research grant, PAK/RCA/8990), was used for the dose calculations. The sensitivity of the dose results to different exhaust flow rates and atmospheric stability classes was studied. The effect of assuming a constant activity concentration (as a function of time) within the containment air volume and an exponentially decreasing air concentration on the time-integrated dose was also studied for various flow rates (1000-50,000 m3 h-1). The comparison indicated that the results were insensitive to the containment air exhaust rates up to or below 2000 m3 h-1, when the prediction with the constant activity concentration assumption was compared to an exponentially decreasing activity concentration model. The results also indicated that the plume touchdown distance increases with increasing atmospheric stability. (note)

  1. Time-integrated thyroid dose for accidental releases from Pakistan Research Reactor-1.

    Raza, S Shoaib; Iqbal, M; Salahuddin, A; Avila, R; Pervez, S

    2004-09-01

    The two-hourly time-integrated thyroid dose due to radio-iodines released to the atmosphere through the exhaust stack of Pakistan Research Reactor-1 (PARR-1), under accident conditions, has been calculated. A computer program, PAKRAD (which was developed under an IAEA research grant, PAK/RCA/8990), was used for the dose calculations. The sensitivity of the dose results to different exhaust flow rates and atmospheric stability classes was studied. The effect of assuming a constant activity concentration (as a function of time) within the containment air volume and an exponentially decreasing air concentration on the time-integrated dose was also studied for various flow rates (1000-50000 m3 h(-1)). The comparison indicated that the results were insensitive to the containment air exhaust rates up to or below 2000 m3 h(-1), when the prediction with the constant activity concentration assumption was compared to an exponentially decreasing activity concentration model. The results also indicated that the plume touchdown distance increases with increasing atmospheric stability. PMID:15511022

  2. Dose reconstruction starting from the pre-dose effect of quartz: combined procedure of additive dose and multiple activation

    The pre-dose effect of the 110 C thermoluminescence (Tl) peak of quartz gives rise to the use of a sensitive technique to estimate of low-level doses under retrospective conditions. However, one can appreciate how aliquots of quartz, from the same mineral fraction, display different sensitivities. In this sense, we herein report on a new measurement protocol based on the aforementioned pre-dose effect. Such procedure includes additive dose and multiple activation steps allows to determine simultaneously the sensitivity changes induced by the thermal activation and the Tl dose dependence. This behaviour let calculate the field accrued dose by interpolation thus permitting an increase of both precision and accuracy. (Author)

  3. Role of sulfite additives in wine induced asthma: single dose and cumulative dose studies

    Vally, H; Thompson, Van P.

    2001-01-01

    BACKGROUND—Wine appears to be a significant trigger for asthma. Although sulfite additives have been implicated as a major cause of wine induced asthma, direct evidence is limited. Two studies were undertaken to assess sulfite reactivity in wine sensitive asthmatics. The first study assessed sensitivity to sulfites in wine using a single dose sulfited wine challenge protocol followed by a double blind, placebo controlled challenge. In the second study a cumulative dose su...

  4. An estimate by two methods of thyroid absorbed doses due to BRAVO fallout in several northern Marshall Islands

    Estimates of the thyroid absorbed doses due to fallout originating from the 1 March 1954 BRAVO thermonuclear test on Bikini Atoll have been made for several inhabited locations in the Northern Marshall Islands. Rongelap, Utirik, Rongerik and Ailinginae Atolls were also inhabited on 1 March 1954, where retrospective thyroid absorbed doses have previously been reconstructed. Current estimates are based primarily on external exposure data, which were recorded shortly after each nuclear test in the Castle Series, and secondarily on soil concentrations of 137Cs in samples collected in 1978 and 1988, along with aerial monitoring done in 1978. External exposures and 137Cs Soil concentrations were representative of the atmospheric transport and deposition patterns of the entire Castle Series tests and show that the BRAVO test was the major contributor to fallout exposure during the Castle series and other test series which were carried out in the Marshall Islands. These data have been used as surrogates for fission product radioiodines and telluriums in order to estimate the range of thyroid absorbed doses that may have occurred throughout the Marshall Islands. Dosimetry based on these two sets of estimates agreed within a factor of 4 at the locations where BRAVO was the dominant contributor to the total exposure and deposition. Both methods indicate that thyroid absorbed doses in the range of 1 Gy (100 rad) may have been incurred in some of the northern locations, whereas the doses at southern locations did not significantly exceed levels comparable to those from worldwide fallout. The results of these estimates indicate that a systematic medical survey for thyroid disease should be conducted, and that a more definitive dose reconstruction should be made for all the populated atolls and islands in the Northern Marshall Islands beyond Rongelap, Utirik, Rongerik and Ailinginae, which were significantly contaminated by BRAVO fallout. 30 refs., 2 figs., 10 tabs

  5. An estimate by two methods of thyroid absorbed doses due to BRAVO fallout in several Northern Marshall Islands.

    Musolino, S V; Greenhouse, N A; Hull, A P

    1997-10-01

    Estimates of the thyroid absorbed doses due to fallout originating from the 1 March 1954 BRAVO thermonuclear test on Bikini Atoll have been made for several inhabited locations in the Northern Marshall Islands. Rongelap, Utirik, Rongerik and Ailinginae Atolls were also inhabited on 1 March 1954, where retrospective thyroid absorbed doses have previously been reconstructed. The current estimates are based primarily on external exposure data, which were recorded shortly after each nuclear test in the Castle Series, and secondarily on soil concentrations of 137Cs in samples collected in 1978 and 1988, along with aerial monitoring done in 1978. The external exposures and 137Cs soil concentrations were representative of the atmospheric transport and deposition patterns of the entire Castle Series tests and show that the BRAVO test was the major contributor to fallout exposure during the Castle series and other test series which were carried out in the Marshall Islands. These data have been used as surrogates for fission product radioiodines and telluriums in order to estimate the range of thyroid absorbed doses that may have occurred throughout the Marshall Islands. Dosimetry based on these two sets of estimates agreed within a factor of 4 at the locations where BRAVO was the dominant contributor to the total exposure and deposition. Both methods indicate that thyroid absorbed doses in the range of 1 Gy (100 rad) may have been incurred in some of the northern locations, whereas the doses at southern locations did not significantly exceed levels comparable to those from worldwide fallout. The results of these estimates indicate that a systematic medical survey for thyroid disease should be conducted, and that a more definitive dose reconstruction should be made for all the populated atolls and islands in the Northern Marshall Islands beyond Rongelap, Utirik, Rongerik and Ailinginae, which were significantly contaminated by BRAVO fallout. PMID:9314227

  6. [Thyroid cancer].

    Nagayama, Yuji

    2012-03-01

    The thyroid glands are a vulnerable organ to ionizing radiation. Indeed the epidemiological studies have revealed an increase in the incidences of thyroid cancer among atomic bomb survivors in Hiroshima and Nagasaki and radiation casualties in Chernobyl. The carcinogenic risk for the thyroids is dependent on radiation dose, and higher in younger people. Recent advances in molecular biology contribute to clarify the mechanisms for thyroid carcinogenesis at genetic and molecular levels. Here radiation-induced thyroid carcinogenesis is reviewed from epidemiological data to basic research. PMID:22514922

  7. Modeling the absorbed dose to the common carotid arteries following radioiodine treatment of benign thyroid disease

    la Cour, Jeppe Lerche; Hedemann-Jensen, Per; Søgaard-Hansen, Jens;

    2013-01-01

    External fractionated radiotherapy of cancer increases the risk of cardio- and cerebrovascular events, but less attention has been paid to the potential side effects on the arteries following internal radiotherapy with radioactive iodine (RAI), i.e. 131-iodine. About 279 per million citizens in the...... western countries are treated each year with RAI for benign thyroid disorders (about 140,000 a year in the EU), stressing that it is of clinical importance to be aware of even rare radiation-induced side effects. In order to induce or accelerate atherosclerosis, the dose to the carotid arteries has to...... exceed 2 Gy which is the known lower limit of ionizing radiation to affect the endothelial cells and thereby to induce atherosclerosis....

  8. Clinical study of 312 cases with matastatic differentiated thyroid cancer treated with large doses of 131 I

    ZHU Rui-sen; YU Yong-li; LU Han-kui; LUO Quan-yong; CHEN Li-bo

    2005-01-01

    @@ Patients with metastatic thyroid cancer (MTC) was routinely treated with a small dose of 131I before 1989. After that we have been switched to multiple courses of large dose 131I therapy. In this paper, the therapeutic result and its effect, in particular on bone marrow depression, pulmonary, parathyroid and salivary gland function as well as chromosome aberration1-3 were observed and reported.

  9. Low radiation dose to relatives after discharge of thyroid cancer patients treated with I-131

    Remy, H.; Camps, E. [Pharmacy, Institut de Cancerologie Gustave Roussy, Villejuif (France); Ricard, M.; Lavielle, F.; Coulot, J. [Medical Physics, Institut de Cancerologie Gustave Roussy, Villejuif (France); Borget, I. [Health Economics, Institut de Cancerologie Gustave Roussy, Villejuif (France); Schhumberger, M. [Nuclear Medicine, Institut de Cancerologie Gustave Roussy, Villejuif (France); University Paris-sud, Bicetre (France)

    2012-07-01

    Patients treated with I-131 for thyroid carcinoma are potential source of radiation exposure for other individuals. In order to provide more reliable information to patients and relatives, this study evaluated the radiation dose received by family members after discharge from the hospital. Three main observations can be drawn. First, rhTSH (recombinant human Thyrotropin) stimulation leads to lower irradiation when mean rate is considered (cumulated irradiation divided by time contact) 1.4 {mu}Sv per hour compared to 1.6 {mu}Sv with withdrawal. However, this had no impact on the radiation dose received by relatives, because of a longer time spent close to the patient when rhTSH is used. Secondly, the mean cumulated radiation dose delivered to the relatives during the 7 days following discharge was similar with either rhTSH (58 {mu}Sv) or withdrawal patients (49.6 {mu}Sv). Thirdly, in euthyroid patients after rhTSH, the whole body retention of I-131 after three days of hospitalization is significantly lower than in hypothyroid patients after withdrawal. The hospital stay can be shortened when rhTSH is used

  10. Adjuvant radioactive iodine (I131) therapy in patients with papillary thyroid cancer: comparison of ablation outcome post low and high doses of I131

    Full text of publication follows. Introduction: I131 ablation post total thyroidectomy is a well established adjuvant therapy in patients with papillary thyroid cancer. Many factors can affect ablation outcome including size of remnant thyroid tissue, stage of the disease and given dose of I131. Some authors stated that small doses of I131 can achieve successful complete ablation outcome comparable to high ablative dose. Aim: the aim of the current study is to compare successful complete ablation rate using low I131 ablation dose (30 mCi) versus high dose (100 mCi) post total thyroidectomy in patients with papillary thyroid cancer confined to the thyroid gland. Patients and methods: 129 patients with papillary thyroid cancer confined to the thyroid gland, with no regional lymph nodal or systemic metastases, candidates for I131 ablation therapy post total thyroidectomy, were included in the current study. 61 patients received 30 mCi ablative dose on our patient basis. The remaining 68 patients received high ablation dose (100 mCi). All patients performed follow up I131 whole body scan, neck ultrasound and unsuppressed serum thyroglobulin level (Tg) 6-9 months post I131 therapy. Successful complete ablation was considered in absence of any I131 avid thyroid tissue in the neck, free neck ultrasound and Tg level < 2 ng/ml. Results: successful complete ablation post 30 mCi of I131 was noted in 36 out of 61 patients (59%). On the other hand, this was observed post 100 mCi in 56 out of 68 patients (82.3%), with a statistically significant difference between both groups (p<0.05). Conclusion: in patients with papillary thyroid cancer confined to the thyroid gland, candidates for I131 ablation therapy post total thyroidectomy, high ablation dose of I131 (100 mCi) has significantly higher successful complete ablation rate compared to small I131 dose (30 mCi). (authors)

  11. BRAF mutation in papillary thyroid microcarcinoma – additional marker of risk stratification

    Dmitriy Yuriyevich Semyonov

    2014-11-01

    Full Text Available BackgroundPapillary thyroid microcarcinoma (PTMC is heterogeneous group of tumor less than 1 cm in the diameter. The volume of surgical treatment stay unstable because unclear biological potential of PTMC.AimThe aim of our study was to assess the utility of BRAF gene mutation as preoperative additional marker of risk stratification.Materials and methodsWe include 44 patient who were operated in general surgery department Pavlov State Medical University from 2001 to 2013. In all 44 cases BRAF gene mutation was detected and compared with clinic-morphological features (multifocality, invasive growth, lymph node metastasis, recurrence retrospectivelyResultsIn our study the frequency of BRAF gene mutation was 68.2%. On multivariate regression analysis the presence of bilateral tumoural foci, lymph node metastasis and the presence of capsular invasion were significantly related to BRAF positive gene status.ConclusionsThus, appropriate volume for the BRAF positive PTMC is thyroidectomy with central compartment lymph node dissection.

  12. Intake ratio of 131I to 137Cs derived from thyroid and whole-body doses to Fukushima residents

    This study deals with the intake ratio of 131I to 137Cs that allows for the utilisation of late whole-body measurements to reconstruct the internal thyroid doses to Fukushima residents. The ratio was derived from the thyroid dose distribution of children and the effective dose distribution of adults based on the assumption that various age groups of persons inhaled the two nuclides at the same activity ratio and at around the same time, while taking into account age-dependent ventilation rates. The two dose distributions were obtained from residents of Iitate village and Kawamata town, located northwest of Fukushima Daiichi nuclear power plant (FDNPP). As a result, the intake ratios for the residents were 2-3, which was much smaller than the activity ratio observed in air sampling. A main reason for this discrepancy presumably lies in the relatively smaller thyroid uptake for iodine in the Japanese subjects than that in the reference persons on whom the biokinetic model promulgated by International Commission on Radiological Protection is based. The actual intake ratio of the two nuclides is believed to have been higher south of the FDNPP; however, this would depend on which of three significant plume events dominantly contributed to the intake for individuals. Further studies are needed to clarify this issue as a part of the reconstruction of early internal doses related to the FDNPP accident. (authors)

  13. Intake ratio of 131I to 137Cs derived from thyroid and whole-body doses to Fukushima residents.

    Kim, Eunjoo; Kurihara, Osamu; Tani, Kotaro; Ohmachi, Yasushi; Fukutsu, Kumiko; Sakai, Kazuo; Akashi, Makoto

    2016-03-01

    This study deals with the intake ratio of (131)I to (137)Cs that allows for the utilisation of late whole-body measurements to reconstruct the internal thyroid doses to Fukushima residents. The ratio was derived from the thyroid dose distribution of children and the effective dose distribution of adults based on the assumption that various age groups of persons inhaled the two nuclides at the same activity ratio and at around the same time, while taking into account age-dependent ventilation rates. The two dose distributions were obtained from residents of Iitate village and Kawamata town, located northwest of Fukushima Daiichi nuclear power plant (FDNPP). As a result, the intake ratios for the residents were 2-3, which was much smaller than the activity ratio observed in air sampling. A main reason for this discrepancy presumably lies in the relatively smaller thyroid uptake for iodine in the Japanese subjects than that in the reference persons on whom the biokinetic model promulgated by International Commission on Radiological Protection is based. The actual intake ratio of the two nuclides is believed to have been higher south of the FDNPP; however, this would depend on which of three significant plume events dominantly contributed to the intake for individuals. Further studies are needed to clarify this issue as a part of the reconstruction of early internal doses related to the FDNPP accident. PMID:25982788

  14. Thyroid radiation dose during panoramic and cephalometric dental x-ray examinations

    Radiation exposure from panoramic equipment can be reduced significantly by use of smaller film, adjustment of the beam height to the height of the smaller film, and careful positioning of patients. These techniques have no adverse effect on the quality of the diagnostic information needed in dentistry. In addition to describing methods of reducing exposures from panoramic machines, this study demonstrates that the use of a barrier collar during static, cephalometric examinations can appreciably reduce thyroid exposure. Since the objective is to obtain diagnostic information from the film without irradiating the thyroid, the application of a lead-impregnated collar is a minor inconvenience, easily borne by the patient and operator. It should be noted that the use of the collar during panoramic examinations affords little or no protection since the relative motion of the panoramic machine places the axis of movement inside the head and neck of the patient. While the evolution of diagnostic radiology may have reached a high level of technical refinement of equipment and film, the clinician still must avoid unnecessary exposure for x-ray examinations and must carefully select the best type of examination to be used for each patient. For example, a complete panoramic examination to determine the position of a known unerupted third molar tooth is probably not an exercise of good judgment since other examinations, such as periapical, could yield the same information with less exposure. Decisions must be made with good judgment, value being placed on relative risks versus the benefits of diagnostic yield

  15. Iodine-131 dose dependent gene expression in thyroid cancers and corresponding normal tissues following the Chernobyl accident.

    Michael Abend

    Full Text Available The strong and consistent relationship between irradiation at a young age and subsequent thyroid cancer provides an excellent model for studying radiation carcinogenesis in humans. We thus evaluated differential gene expression in thyroid tissue in relation to iodine-131 (I-131 doses received from the Chernobyl accident. Sixty three of 104 papillary thyroid cancers diagnosed between 1998 and 2008 in the Ukrainian-American cohort with individual I-131 thyroid dose estimates had paired RNA specimens from fresh frozen tumor (T and normal (N tissue provided by the Chernobyl Tissue Bank and satisfied quality control criteria. We first hybridized 32 randomly allocated RNA specimen pairs (T/N on 64 whole genome microarrays (Agilent, 4×44 K. Associations of differential gene expression (log(2(T/N with dose were assessed using Kruskall-Wallis and trend tests in linear mixed regression models. While none of the genes withstood correction for the false discovery rate, we selected 75 genes with a priori evidence or P kruskall/P trend <0.0005 for validation by qRT-PCR on the remaining 31 RNA specimen pairs (T/N. The qRT-PCR data were analyzed using linear mixed regression models that included radiation dose as a categorical or ordinal variable. Eleven of 75 qRT-PCR assayed genes (ACVR2A, AJAP1, CA12, CDK12, FAM38A, GALNT7, LMO3, MTA1, SLC19A1, SLC43A3, ZNF493 were confirmed to have a statistically significant differential dose-expression relationship. Our study is among the first to provide direct human data on long term differential gene expression in relation to individual I-131 doses and to identify a set of genes potentially important in radiation carcinogenesis.

  16. Parathyroid changes after high dose radioactive iodine in patients with thyroid cancer

    The study aimed to investigate the effect of high dose radioactive iodine (RAI) on parathyroid function in patients with differentiated thyroid cancer. Nineteen patients (8 men/11 women, age 46.5±13.2 years) undergoing RAI for thyroid remnant ablation were enrolled in the study. The biochemical parameters related to parathyroid function [serum calcium (Ca), phosphate (P), creatinine (Cr), alkaline phosphatase (ALP), intact parathyroid hormone (iPTH), urinary Ca, cAMP concentrations and the maximum tubular capacity for phosphate per unit volume of glomerular filtrate (TmP/GFR)] were evaluated at baseline and at the 1st, 3rd, 6th and 12th months of RAI administration. SPSS 15.0 was used for statistical analysis. For all patients, thyroid-stimulating hormone levels were >30 U/ml at baseline and <0.1 U/ml at the following visits. Serum iPTH levels were decreased significantly at the 6th month and reached basal levels at the 12th month (baseline vs. 6th p=0.027, 1st vs. 6th p=0.011, 3rd vs. 6th p=0.047, 3rd vs. 12th p=0.014, 6th vs. 12th p=0.001). At the 6th month, P and TmP/GFR levels were higher (p=0.036, 0.017, respectively), and urinary cAMP measurements were lower (p=0.020) compared to those of the 1st month. No difference was detected concerning the other parameters. Serum Ca levels decreased below 2.1 mmol/l in several patients (n=5 at 1st month, n=4 at 3rd month, n=8 at 6th month and n=3 at 12th month) without clinical symptoms. The study indicated a transient decline in PTH levels at the 6th month following RAI therapy. Although this decrease did not cause symptoms in any of the present cases, this pattern might be important especially in individuals with diminished parathyroid background. (author)

  17. Development of a method for the retrospective reconstruction of the thyroid dose for children in Belarus after the reactor accident of Chernobyl by determination of the 129I-concentration in soil

    About four years after the reactor accident of Chernobyl, a pronounced rise in childhood thyroid gland cancer was registered throughout the republic of Belarus. It was soon understood that most likely the shortlived radioiodine isotope 131I was responsible for this effect. As there were only a few direct measurements performed to measure the iodine activity in thyroids, other methods had to be developed to reconstruct the thyroid dose of those children who suffered from thyroid cancer. First approaches to this task were performed by the determination of caesium deposition densities on ground which were correlated to a few available measurements of 131I in soil samples. But soon it had to be realized that this approach was not appropriate for a consistent retrospective dose reconstruction due to the patchy depositions patterns and the different release and transport mechanisms between caesium and iodine. For a new approach it was suggested to determine the 129I concentration in soil by introducing a newly developed extraction procedure that produces samples which can be measured for 129I by means of Accelerator Mass-spectrometry (AMS). Both techniques were sequentially applied to soil samples taken during two successive field-expeditions to Belarus. They are discussed in detail in this thesis. To assess the thyroid dose the concentration of 131I in soil was then determined using the assumption of a constant release and transport ratio between 129I and 131I. The inferred 131I deposition densities on ground were used as input data to a radiological food-chain model and an average integrated thyroid dose to certain age groups of various resistance areas were calculated for the main exposure path of milk ingestion. An intercomparison between this new approach and the results of direct thyroid activity measurements was performed. In addition to these two approaches two others were applied for comparison. The first one was based on the generalization of a correlation

  18. Autoimmune thyroiditis with severe hypothyroidism resistant to the treatment with high peroral doses of thyroxine: case report.

    Payer, J; Sladekova, K; Kinova, S; Cesnakova, Z; Killinger, Z; Krizko, M; Klimes, I; Langer, P

    2000-12-01

    Female patient (42 yr) suffered from autoimmune thyroiditis resulting in severe hypothyroidism. She was treated for several years by district physician with the dose of 150 microg L-thyroxine daily. Since the level of TSH was repeatedly very high and no improvement of clinical signs has been observed, she was referred to the Medical Faculty Hospital. Thyroid ultrasound showed remarkable diffuse hypoechogenicity, thyroid scintigraphy showed enlarged thyroid with low 99mTc uptake, TRH test was normal, thin needle biopsy supported autoimmune thyroiditis. X-ray examination showed normal sella turcica and no changes in the pituitary were observed with computer tomography. In spite of increasing the dose of peroral L-thyroxine to 300 microg/d and later to 500 microg/d the clinical status and TSH level did not improve. The patient was originally suspected from malabsorption of thyroxine. However, the test with a large single peroral dose (1000 microg) of L-thyroxine showed a rapid decrease of TSH level (from 126 to 75 mU/l) and increase of total T4 level (from 18 to 64 nmol/l) within 4 hr. Later the patient has been treated with intravenous L-thyroxine (500 microg every 3-4 days for 4 weeks) which resulted in the decrease of TSH level to 10 mU/l and increase of T4 level to 80-100 nmol/l. After that it was concluded that the problem is a poor compliance of the patient who apparently does not actually take the medication, although she always claimed that she is doing so. Referring to some similar cases described in the literature the case was classified as thyroxine pseudomalabsorption. In spite that this problem has been explained to her and her relatives, she refused to take any medication and is consistently neglecting all invitations to further examinations. PMID:11137979

  19. First results of radioiodine therapy of multifocal and disseminated functional thyroid autonomy using a TcTUs-adapted dose concept

    Aim: The presented study examines prospectively the efficiency of a dose concept for radioiodine therapy (RIT) adapted to the pretherapeutic 99mTc-pertechnetate thyroid uptake under suppression (TcTUs) in patients with multifocal (MFA) and disseminated (DISA) autonomy. This concept considers the total thyroid as target volume and uses target doses from 150 Gy to 300 Gy according to the TcTUs, which is as a measure for the 'autonomous volume' of the thyroid. Methods: The data of 75 patients (54 female, 21 male; age 71±9 years) with MFA or DISA were evaluated. RIT was performed on patients presenting with normal values for free triiodothyronine and thyroxine and endogenous suppression of the basal thyrotropin (TSH). The following target doses were used: For a TcTUs of 1,5-2,5% 150 Gy, for 2,51-3,5% 200 Gy, for 3,51-4,5% 250 Gy, and for >4,5% 300 Gy. The radiation dose to be administered was calculated using a modified Marinelli formula. The therapy was considered as successful when the basal TSH was above 0,5 mU/l and autonomous areas had disapeared in thyroid scintigraphy or the TcTU was below 1,5%, respectively. The average follow-up period was 8±4 months. Results: The success rates average to 92%. Only in one case a subsequent subclinical hypothyroidism and in a further case an immunogenic hyperthyroidism occured. Conclusion: The presented data indicate, that even patients with a marked autonomy (TcTUs>3,5%) can thus expected to be cured by of a onetime therapy with success rate of over 90% using the presented dose concept. The rate of early hypothyroidism can alltogether be estimated as very low. (orig.)

  20. Salivary gland protection by amifostine in high-dose radioiodine therapy of differentiated thyroid cancer

    Bohuslavizki, K.H.; Klutmann, S.; Bleckmann, C.; Mester, J.; Clausen, M. [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Dept. of Nuclear Medicine; Brenner, W.; Lassmann, S.; Henze, E. [Kiel Univ. (Germany). Clinic of Nuclear Medicine

    1999-02-01

    Quantitative salivary gland scintigraphy using 100 to 120 MBq Tc-99m-pertechnetate was performed in 17 patients with differentiated thyroid cancer prior to and 3 months after radioiodine treatment with 6 GBq I-131. Eight patients were treated with 500 mg/m{sup 2} amifostine prior to high-dose radioiodine treatment and compared retrospectively with 9 control patients. Xerostomia was graded according to WHO criteria. In 9 control patients high-dose radioiodine treatment significantly (p<0.01) reduced Tc-99m-pertechnetate uptake by 35.4{+-}22.0% and 31.7{+-}21.1% in parotid and submandibular glands, respectively. Of these 9 patients, 3 exhibited xerostomia Grade I (WHO). In contrast, in 8 amifostine-treated patients, there was no significant (p=0.878) decrease in parenchymal function following high-dose radioiodine treatment, and xerostomia did not occur in any of them. (orig.) [Deutsch] Im Rahmen eines Heilversuchs wurde eine limitierte Anzahl von Patienten untersucht. Vor und drei Monate nach Gabe von 6 GBq I-131 wurde eine quantitative Speicheldruesenszintigraphie mit 100 bis 120 MBq Tc-99m-Pertechnetat an 17 Patienten mit differenzierten Schilddruesenkarzinomen durchgefuehrt. Acht Patienten erhielten vor Radiojodtherapie 500 mg/m{sup 2} Amifostin und wurden mit einer historischen Kontrollgruppe aus neun Patienten verglichen. Eine Xerostomie wurde nach WHO-Kriterien beurteilt. Die Patienten der Kontrollgruppe wiesen sowohl fuer die Glandulae parotides als auch fuer die Glandulae submandibulares eine signifikante Verminderung der Tc-99m-Pertechnetat-Aufnahme um 35,4{+-}22,0% bzw. 31,7{+-}21,1% als Zeichen einer Parenchymschaedigung auf. Bei drei dieser neuen Patienten fand sich eine Xerostomie Grad I (WHO). Im Gegensatz dazu konnte bei den mit Amifostin behandelten Patienten keine signifikante Verminderung der Parechymfunktion festgestellt werden (p=0,878). Dementsprechend wies keiner dieser Patienten eine Xerostomie auf. (orig.)

  1. A Study on the Radiation Dose of 131I in the Thyroid Gland during the Treatment of Hyperthyroidism

    53 patients with hyperthyroidism have been analyzed with special reference to therapeutic response to radioactive iodine(131I) treatment. Mean effective half-life, 24 hour uptake rate and radiation dose of 131I in hyperthyroid patients included in this study were respectively. 1) Mean effective half-life of 131I was 4.7±1.5 days in the trace dose and 5.0±1.5 days in the therapeutic dose. 2) Mean 24 hour uptake rate of 131I was 72.7±11.1% in the tracer dose and 73.4±12.3% in the therapeutic dose. 3) Mean radiation dose of 131I was 5319±2648 RAD as predicted and 5692±2843 RAD as actual. A single dose of radioactive iodine treatment was satisfactory in 34 patients (radioiodine resistant) A radioiodine resistant group of patients with hyperthyroidism was distinctively characteristic in the following aspects. 1) Mean thyroid weight calculated in the resistant group (63.9±14.0 gm) was significantly (p131I in the resistant group (3,684±1,745 RAD) was significantly (p131I in the resistant group (4,100±1,691 RAD) was significantly (p131I among the groups (p>0.05). 7) The average mean % difference of effective half-life, uptake rate and radiation dose measured following the tracer and therapeutic dose of 131I were not statistically significant (p>0.05). Therefore effective half-life, uptake rate and radiation dose of the therapeutic dose of 131I were readily predictable following the tracer dose of 131I. 8) It is concluded that the possibility of resistance to radioactive iodine treatment may be anticipated in patients with thyroid gland large in size and compromised 131I uptake rate.

  2. Study of immediate and long-term side effects on thyroid cancer patients caused by high-dose radioiodine therapy

    The well differentiated thyroid cancer patients had a better prognosis. High-dose radioiodine therapy may induce immediate and long-term side effects to patients. The aim of the author is to investigate the side effects after high-dose radioiodine therapy on thyroid cancer patients and the relation with cumulative therapy dosage. According to the common side effects of 131I therapy, 10 questions was chosen to set up a standard questionnaire. Patients were followed up by senior nuclear medicine physicians and the results were analyzed and compared. The results showed that the late symptom of sialadenitis and severe dry mouth were intensively related with cumulative therapy dosage. It is suggested that during the therapy certain necessary means should be adopted to reduce the potential side effects and improve the patients' life quality

  3. Thyroid diseases

    This chapter reviews the correlation between thyroid disease, other than cancer, and radiation in the literature. Radiation-induced thyroid disturbance is discussed in the context of external and internal irradiation. External irradiation of 10 to 40 Gy may lower thyroid function several months or years later. Oral administration of I-131 is widely given to patients with Basedow's disease; it may also lower thyroid function with increasing radiation doses. When giving 70 Gy or more of I-131, hypothyroidism has been reported to occur in 20-30% and at least 10%. Thyroiditis induced with internal I-131 irradiation has also been reported, but no data is available concerning external irradiation-induced thyroiditis. The incidence of nodular goiter was found to be several ten times higher with external irradiation than internal irradiation. Thyroid disturbance is correlated with A-bomb survivors. A-bomb radiation can be divided into early radiation within one minute after A-bombing and the subsequent residual radiation. Nodular goiter was significantly more frequent in the exposed group than the non-exposed group; it increased with increasing radiation doses and younger age (20 years or less) at the time of exposure. The incidence of decrease in thyroid function was higher with increasing radiation doses. However, in the case of Nagasaki, the incidence of hypothyroidism was significantly higher in the low-dose exposed group, especially A-bomb survivors aged 10-39 at the time of exposure and women. (N.K.)

  4. Thyroid and Whole-Body Dose Reconstruction in Russia Following the Chernobyl Accident: Review of Progress and Results

    Stepanenko, V.; Skvortsov, V.; Tysb, A.; Ivannikov, A.; Kondrashov, A.; Tikunov, D.; Iaskova, E.; Shakhtarin, V.; Petin, D.; Parshkov, E.; Chernichenko, L.; Snykov, V.; Orlov, M.; Gavrihn, Yu.; Khrousch, V.; Shinkarev, S

    1998-07-01

    The results of direct measurements of radioactive iodine content in the human thyroid gland (in Bryansk and Kaluga regions, Russia) and also available data on {sup 131}I and {sup 137}Cs contamination of the soil were used for investigation of correlations between the mean thyroid dose for adults in settlements and local levels of {sup 137}Cs and/or {sup 131}I soil contamination. On the basis of this analysis a model was developed showing how to evaluate retrospectively the thyroid absorbed doses. For individual dose reconstruction using an 'age/milk' scale, special questioning of inhabitants was carried out. Mean dose values in the exposed population of each contaminated Russian settlement were evaluated using the model. The total collective dose due to internal exposure of the thyroid gland by iodine radionuclides equates to 106,500 person.Gy in the population of the most contaminated territories of four Russian regions. The maximum value was found in the Bryansk region (73,000 person.Gy). New data concerning the delay in pasturing in different regions as well as time dependencies of the fallout were taken into account. As a result the dose estimations differ from previous published data. Comparisons between the developed method and the other independent approaches indicate a concordance within a factor 3. For application of the EPR tooth enamel dosimetry on a wide scale, estimation of accumulated external doses are demonstrated and analysed. There were about 2500 tooth samples measured from the contaminated region as well as from the non-contaminated territories of Russia. The investigated factors are: (1) effect of solar light on front teeth; (2) correction for the energy dependence of the EPR response; (3) presence in the enamel of some intrinsic signals; (4) age dependent doses due to natural background radiation. The average values of EPR dose with special account taken of correction factors are presented. The tendency of average doses to grow with

  5. Radiation dose-rate reduction pattern in well-differentiated thyroid cancer treated with I/sup -131/

    To determine the patterns of dose rate reduction in single and multiple radioiodine (I-131) therapies in cases of well differentiated thyroid cancer patients. Study Design: Analytical series. Place and Duration of Study: Department of Nuclear Medicine and Radiation Physics, Multan Institute of Nuclear Medicine and Radiotherapy (MINAR), Multan, Pakistan, from December 2006 to December 2013. Methodology: Ninety three patients (167 therapies) with well differentiated thyroid cancer treated with different doses of I-131as an in-patient were inducted. Fifty four patients were given only single I-131 herapy dose ranging from 70 mCi (2590 MBq) to 150 mCi (5550 MBq). Thirty nine patients were treated with multiple I-131radioisotope therapy doses ranging from 80 mCi (2960 MBq) to 250 mCi (9250 MBq). T-test was applied on the sample data showed statistically significant difference between the two groups with p-value (p < 0.01) less than 0.05 taken as significant. Results: There were 68 females and 25 males with an age range of 15 to 80 years. Mean age of the patients were 36 years. Among the 93 cases of first time Radio Active Iodine (RAI) therapy, 59 cases (63%) were discharged after 48 hours. Among 39 patients who received RAI therapy second time or more, most were discharged earlier after achieving acceptable discharge dose rate i.e 25 micro r; 2 out of 39 (5%) were discharged after 48 hours. In 58% patients, given single I-131 therapy dose, majority of these were discharged after 48 hours without any major complications. Conclusion: For well differentiated thyroid cancer patients, rapid dose rate reduction is seen in patients receiving second or subsequent radioiodine (RAI) therapy, as compared to first time receiving RAI therapy. (author)

  6. Contributions of short-lived radioiodines to thyroid doses received by evacuees from the Chernobyl area estimated using early in vivo activity measurements

    A series of in-vivo gamma spectrometric measurements of 65 people, evacuated from Pripyat 1.5 days after the Chernobyl Nuclear Power Plant Unit 4 explosion was performed in St. Petersburg, Russia, as early as 30 April 1986. The historical spectra and interviews were recently processed and the results used for thyroid dose estimation. Activities of 131I in thyroid and 132Te in lungs were determined easily; for estimation of 132I and 133I activities in thyroid, sophisticated methods of spectra processing were developed. According to thyroid measurement data, the mean ratio of 133I/131I activities (at the time of the accident) inhaled by residents of Pripyat was 2.0. The mean ratio of thyroid dose from 133I inhalation to that caused by 131I amounts to 0.3, which confirms accuracy of dose estimates based on the evolution of the Chernobyl accident. The mean ratio of 132I activity in thyroid to that of 132Te in lungs was assessed from the human measurement data to be 0.2, which is in reasonable agreement with the metabolic properties of these radionuclides. The mean ratio of thyroid dose from 132I originating from 132Te deposited in lungs to the dose caused by 131I was 0.13 ± 0.02 for Pripyat residents who did not take KI pills and 0.9 ± 0.1 for persons who took KI pills. Thus, the contribution of short-lived radioiodines to total thyroid dose of Pripyat residents, which was on average 30% for persons who did not apply stable iodine prophylaxis, and about 50% for persons who took KI pills on 26-27 April, should be accounted for in the assessment of thyroid health effects. (author)

  7. Reduction of Radiation Dose Requirements of Foods by Additives

    Utilizing a recording photometer, a rapid turbidimetric method was worked out for the determination of nisin and tylosin activity. Those antibiotics affected by irradiation with X-rays in the range of 0 to 800 krad were also investigated. In a solution of pH 5.7 containing pea extract, the activity of the antibiotics decreased at a high rate when irradiated up to 200 krad, however, this rate slowed down with further radiation treatment. Tylosin lactate proved more radiation resistant than nisin. When treated with dosages between 400 and 800 krad the activity of nisin decreased by 73 to 87% and that of tylosin lactate by only 52 to 57%. During one-month storage at room temperature the residual activity of both the irradiated and untreated antibiotic solutions remained practically unchanged. The addition of antibiotics increased the preserving effect of X-rays. A 1:1 mixture of peas and a solution containing 4% sugar and 1.5% salt was heat treated for 15 minutes at 70°C. Samples taken from the liquid phase of this mixture were treated with various radiation-antibiotic combinations. When 100 ppm Nisaplin or 1 ppm tylosin lactate was added the radiation dose requirement was a quarter of that needed in the control samples to ensure microbiological stability. (author)

  8. Dosimetric contribution of organs of biokinetics of 99mTc and 123I to estimate radiation doses in thyroids of children of 1 and 5 years

    The absorbed doses by thyroids during uptake studies through biokinetics of radiopharmaceuticals containing 123I (iodine) or 99mTc (pertechnetate) are estimated. Using the MIRD scheme and the representation of Cristy-Eckerman for thyroids in children of 1 and 5 years, the objective of the study was to determine whether the dosimetric biokinetic contributions of the organs of 123I (iodide) and 99mTc (pertechnetate) biokinetic are significant in the estimated of the absorbed dose for thyroid uptake studies

  9. Milk production and distribution in low-dose counties for the Hanford Thyroid Disease Study

    This report identifies sources of milk consumed by residents of Ferry, Okanogan, and Stevens Counties. This information will be used by the Hanford thyroid Disease Study to determine whether thyroid disease has been increased among people exposed to past iodine--131 emissions from Hanford Site Facilities

  10. Scattered radiation dose to radiologist's cornea, thyroid and gonads while performing some x-ray fluoroscopic investigations

    The mankind has been immensely benefited from discovery of X-ray and it has found wide spread application in diagnosis and treatment. Radiation is harmful and can produce somatic and genetic effects in the exposed person. International Commission on Radiation Protection (ICRP) has recommended a system of dose limitation based on principle of ALARA. All the efforts should be made to keep the radiation dose to the radiation worker as low as possible. Fluoroscopy gives maximum dose to the patient and staff and hence we have attempted to quantify the scattered radiation dose to the cornea, thyroid and gonads of the radiologist performing fluoroscopic examinations such as barium meal, barium swallow, barium enema, myelography, histerosalpingography and fracture reduction. Thermoluminescence dosimetry (TLD) method using CaSO4:Dy TLD disc was employed for these measurements. Use of lead apron has reduced the dose to radiologist's gonad. (author). 3 refs., 4 tabs

  11. 131I treatment response in thyroid neoplasms and evaluation of radiation dose complications. A review of ten years of experience

    Full text: Thyroid cancer (TC) is the most common endocrine malignancy, but its management is still a controversial issue that included an interdisciplinary approach who compounds surgery, radioiodine (RAI) therapy and sometimes external radiation therapy. The aim of our work is to evaluate the role of the RAI treatment in well differenciated thyroid carcinoma and its implication in terms of survival and complications. Methods and Material: we collected data from medical records of 215 patients with confirmed TC, registered from 1990-2004 at the Nuclear Medicine Unit, Hospital Temuco, Chile, who received 50 to 150 mCi RAI therapy four to six weeks after lobectomy, partial or total thyroidectomy. Clinical and laboratory examinations were analyzed including blood count, thorax X Ray, whole body I-131 scans, and serum thyroglobulin. Results: the median age at the diagnosis was 51 years, there were 89% females. All patients were treated surgically and recived postoperative RAI treatment. Total thyroidectomy, subtotal thyroidectomy and nodule excision was done in 69%, 31% and 37% of patients respectively. The histopathologic results included papillary (62%), follicular (24%) and papillary-follicular carcinoma (14%). Regional lymph nodes were positive in 36% and distant metastases were detected in 20 %, located in the lungs in all of those patients. Additional RAI doses between 100-200 mCi were administrated in 35% patients after to wait a period longer than 1 year. The overall survival rate at 14 years was 93 %, and recurrent disease was detected in 15%. at 5 years and 20% at 14 years from the diagnosis. There were no major complications and minimal alterations in the blood count was observed. We conclude that total or near total thyroidectomy followed by RAI treatment appears to benefit for better survival and lower recurrence disease. Favorable prognostic management included radioiodine therapy at the primary treatment using high actvities (more than 100 mCi) after

  12. Thyroid Dose Estimation Using WBC and I-131 Concentration in Working Area of Radioisotope Production at Normal Operation

    Thyroid dose estimation at Radioisotope Production Centre workers using WBC and calculation based on I-131 concentration in working area has been done. The aim of this research is to get the relation between WBC result and calculation using I-131 concentration in working area. The result indicates differences in a range of 3,2% to 53,2%. These differences caused of parameters which influence the calculation are not accurate. These results also indicate that dose estimation using WBC is relatively batter and more accurate but need to have certain information about time of intake

  13. Thyroid cancer among children and adolescents in Russia following the Chernobyl accident. Retrospective estimation of thyroid doses and case - control study

    The first large-scale study of thyroid cancer among young people in Russia following the Chernobyl accident was conducted. The study population consists of all children and adolescents (17 years and less) who were resided in Kaluga, Orel and Tula oblasts of Russia at the time of Chernobyl accident. Kaluga, Orel and Tula oblasts are approximately equally contaminated oblasts of Russia (up to 15 Ci/km2 for cesium-137). All prevalent and new carcinoma cases from 1 January 1992 to 31 December 1998 were collected in 1997-1998 years as a result of joint project on thyroid disease conducted by the Medical Radiological Research Center (Russia), International Agency for Research on Cancer (France) and Sasakawa Memorial Health Foundation (Japan). Cases of thyroid cancer were found through the Russia National Medical and Dosimetric Registry and Russian Oncology Dispensaries. All cases were independently hystologically verified by the international panel of pathologists from Russia, Belarus and Europe. There were 12 cases in Kaluga, 27 cases in Orel and 23 cases in Tula oblasts. For each case were randomly selected two and four controls: two controls were matched on age, sex and on settlement of residence at the time of accident; four controls were matched on age, sex and on oblast of residence at the time of accident. Each patient and corresponding controls were examinated by the high-resolution ultrasonographic instrument and were interviewed by special trained medical staff. The new technique for reconstruction of the individual dose of internal irradiation of thyroid with incorporated 131I was developed. The method allows to take into account major factors influencing formation thyroid doses of the population: (1) three sources of receipt 131I in organism of the man: inhalation, consumption of milk and green vegetables; (2) types of food production: public and private (individual) sectors of its (her) manufacture; (3) weather conditions of spring of 1986 in regions of

  14. Predictive value of pyramidal lobe, percentage thyroid uptake and age for ablation outcome after 15 mCi fixed dose of radioiodine-131 in Graves’ disease

    The purpose was to find out the efficacy of fixed 15 mCi radioactive iodine-131 (RAI) dose and predictive values of various factors for inducing hypothyroidism in Graves’ disease (GD). Retrospective study conducted from January 2012 till August 2014. Patients with GD who had a technetium-99m thyroid scan, thyroid antibodies, received fixed 15 mCi RAI and did follow endocrine clinics for at least 6 months were selected. RAI was considered successful if within 6 months of RAI therapy patients developed hypothyroidism. Of the 370 patients with GD who had RAI during study period, 210 (57%) qualified study criteria. Mean age of patients was 48 ± 15 years with female: male ratio of 69:31, positive thyroid antibodies in 61%, means thyroid uptake of 15.09 ± 11.23%, and presence of pyramidal lobe in 40% of total population. Hypothyroidism was achieved in 161 (77%) patients while 49 (23%) patients failed to achieve it (remained either hyperthyroid or euthyroid on antithyroid medication). Patients who became hypothyroid were significantly younger with higher proportion of presence of thyroid antibodies and pyramidal lobe and lower percentage thyroid uptake than those who failed. Multiple logistic regression analysis revealed that age (odds ratio; OR = 2.074), pyramidal lobe (OR = 3.317), thyroid antibodies (OR = 8.198), and percentage thyroid uptake (OR = 3.043) were found to be significant prognostic risk factors for post-RAI hypothyroidism. Gender was found to have nonsignificant association with the development of hypothyroidism. Receiver operating characteristic analysis revealed age <42 years and thyroid uptake <15% as threshold values for the development of post-RAI hypothyroidism. We conclude that fixed (15 mCi) RAI dose is highly effective in rendering hypothyroidism in patients with GD. Age (≤42 years), thyroid uptake (≤15%) and presence of pyramidal lobe are strong predictors of hypothyroidism and must be considered for selecting optimal RAI dose

  15. The significance of 1-131 scan dose in patients with thyroid cancer: determination of ablation: concise communication

    Twenty-four patients with differentiated thyroid cancer were studied with diagnostic I-131 neck chest scans after having undergone bilateral subtotal thyroidectomy and initial I-131 therapy with either 30- or 100-mCi doses. With an endogenous stimulation protocol, follow-up studies were performed with neck and chest scans using 2 and 10 mCi I-131. A 400% increase in sensitivity was found with a 10-mCi dose relative to a 2-mCi dose. Comparison with therapeutic doses of 30 and 100 mCi resulted in further increases in the detection of residual iodine-avid tissue. We conclude that a 2-mCi or lower dose of I-131 is inadequate in evaluating residual iodine-avid tissue visually in patients with thyroid cancer. The study does not answer the critical question of whether it is necessary to treat a patient presenting a negative 2-mCi but a positive 10-mCi scan. It may be appropriate to define ablation visually as well as clinically, with further studies directed toward determining a treatment rationale in this patient population

  16. Thyroid hormone levels and hepatic enzyme activity in lactating dams after gestational exposure to low dose PBDE 47

    Kuriyama, S.N.; Grande, S.W.; Akkoc, Z.; Souza, C.A.M. de; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin; Fidalgo-Neto, A.A. [Oswaldo Cruz Foundation, Rio de Janeiro (Brazil). Lab. of Environmental Toxicology

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are found extensively in the environment (shown by several studies on sentinel animal species), as well as in humans. In rodents, technical commercial PBDE mixtures and individual congeners have shown to interfere with thyroid hormone homeostasis, produce a mix-type induction of hepatic microsomal enzymes, disrupt spontaneous behaviour, impair learning and memory and alter the cholinergic transmitter system. In rat and mice, some technical PBDE commercial mixtures such as DE-71 and Bromkal 70 and the congener PBDE 47 have shown to decrease circulating thyroid hormone levels. PBDEs are also able to induce both hepatic phase I and phase II detoxification enzymes, demonstrated by several investigations in laboratory animals. For example, induction of ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-Odespenthylase (PROD) and uridinediphospho-glucuronosyltransferase (UDPGT) has been shown in rodents and cell lines after exposure to technical mixtures or individual congeners. However, these studies deal with doses much higher than that found in human tissues, highlighting the importance of assessing the adverse effects of doses close to human exposure levels. PBDE 47 is the most predominant congener found in environmental and human samples (including human milk) and, therefore, hazard identification is extremely important for human risk assessment. We administered a single dose to gravid dams on gestation day 6 of either 140 {mu}g/kg BW or 700 {mu}g/kg BW of the congener, 2,2'4,4'-tetrabromo diphenyl ether (PBDE 47). These doses are pertinent to human exposure levels because a study by She et al. found a mean level of 33.3 {mu}g PBDE 47 /kg fat in human breast adipose tissue with a range from 7.01 to 196 {mu}g PBDE 47 /kg fat. In this study, thyroid hormone levels and hepatic enzyme activity were evaluated in lactating dams after in utero administration of low dose PBDE 47.

  17. Estimated dose rates to members of the public from external exposure to patients with {sup 131}I thyroid treatment

    Dewji, S., E-mail: dewjisa@ornl.gov; Bellamy, M.; Leggett, R.; Eckerman, K. [Oak Ridge National Laboratory, 1 Bethel Valley Road, MS-6335, Oak Ridge, Tennessee 37831 (United States); Hertel, N. [Oak Ridge National Laboratory, 1 Bethel Valley Road, MS-6335, Oak Ridge, Tennessee 37831 and Georgia Institute of Technology, 770 State Street, Atlanta, Georgia 30332-0745 (United States); Sherbini, S.; Saba, M. [United States Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

    2015-04-15

    specific activities of {sup 131}I in the thyroid, bladder, and combined remaining tissues were calculated as a function of time after administration. Exposures to members of the public were considered for {sup 131}I patients with normal thyroid uptake (peak thyroid uptake of ∼27% of administered {sup 131}I), differentiated thyroid cancer (DTC, 5% uptake), and hyperthyroidism (80% uptake). Results: The scenario with the patient seated behind the member of the public yielded the highest dose rate estimate of seated public transportation exposure cases. The dose rate to the adjacent room guest was highest for the exposure scenario in which the hotel guest and patient are seated by a factor of ∼4 for the normal and differentiated thyroid cancer uptake cases and by a factor of ∼3 for the hyperthyroid case. Conclusions: It was determined that for all modeled cases, the DTC case yielded the lowest external dose rates, whereas the hyperthyroid case yielded the highest dose rates. In estimating external dose to members of the public from patients with {sup 131}I therapy, consideration must be given to (patient- and case-specific) administered {sup 131}I activities and duration of exposure for a more complete estimate. The method implemented here included a detailed calculation model, which provides a means to determine dose rate estimates for a range of scenarios. The method was demonstrated for variations of three scenarios, showing how dose rates are expected to vary with uptake, voiding pattern, and patient location.

  18. Estimated dose rates to members of the public from external exposure to patients with 131I thyroid treatment

    thyroid, bladder, and combined remaining tissues were calculated as a function of time after administration. Exposures to members of the public were considered for 131I patients with normal thyroid uptake (peak thyroid uptake of ∼27% of administered 131I), differentiated thyroid cancer (DTC, 5% uptake), and hyperthyroidism (80% uptake). Results: The scenario with the patient seated behind the member of the public yielded the highest dose rate estimate of seated public transportation exposure cases. The dose rate to the adjacent room guest was highest for the exposure scenario in which the hotel guest and patient are seated by a factor of ∼4 for the normal and differentiated thyroid cancer uptake cases and by a factor of ∼3 for the hyperthyroid case. Conclusions: It was determined that for all modeled cases, the DTC case yielded the lowest external dose rates, whereas the hyperthyroid case yielded the highest dose rates. In estimating external dose to members of the public from patients with 131I therapy, consideration must be given to (patient- and case-specific) administered 131I activities and duration of exposure for a more complete estimate. The method implemented here included a detailed calculation model, which provides a means to determine dose rate estimates for a range of scenarios. The method was demonstrated for variations of three scenarios, showing how dose rates are expected to vary with uptake, voiding pattern, and patient location

  19. Prophylactic cerebral irradiation in children with leukemia: In vivo evaluation of the irradiation dose applied to the thyroid during prophylactic cerebral irradiation delivered within the framework of the children leukemia treatment; Dosimetrie in vivo pour l`evaluation de la dose recue par la thyroide lors de l`irradiation cerebrale prophylactique delivree dans le cadre du traitement des leucemies de l`enfant

    Ricardi, U.; Rossi, G.; Tessa, M.; Monetti, U.; Verna, R.; Urgesi, A.; Barisone, E.; Besenzon, L.; Corrias, A. [Turin Univ. (Italy)

    1997-09-01

    The aim of this work is to evaluate by in vivo dosimetry, the dose received by the thyroid parenchyma during an encephalon irradiation for children having acute lymphoid leukemia, then to look for a correlation between the thyroid alterations ( hypothyroidism, second tumors) and the dosimetry data. (N.C.). 5 refs.

  20. Thyroid Cancer Rates and 131I Doses from Nevada Atmospheric Nuclear Bomb Tests: An Update

    Gilbert, Ethel S.; Huang, Lan; Bouville, Andre; Berg, Christine D.; Ron, Elaine

    2010-01-01

    Exposure to radioactive iodine (131I) from atmospheric nuclear tests conducted in Nevada in the 1950s may have increased thyroid cancer risks. To investigate the long-term effects of this exposure, we analyzed data on thyroid cancer incidence (18,545 cases) from eight Surveillance, Epidemiology, and End Results (SEER) tumor registries for the period 1973-2004. Excess relative risks (ERR) per Gray (Gy) for exposure received before age 15 were estimated by relating age-, birth year-, sex-, and ...

  1. Lesion dose in differentiated thyroid carcinoma metastases after rhTSH or thyroid hormone withdrawal: {sup 124}I PET/CT dosimetric comparisons

    Freudenberg, Lutz Stefan; Jentzen, Walter; Brandau, Wolfgang; Bockisch, Andreas [University of Duisburg/Essen, Department of Nuclear Medicine, Essen (Germany); Petrich, Thorsten; Knapp, Wolfram H. [Hanover University School of Medicine, Department of Nuclear Medicine, Hanover (Germany); Froemke, Cornelia [Hanover University School of Medicine, Institute of Biometry, Hanover (Germany); Marlowe, Robert J. [Spencer-Fontayne Corporation, Jersey City, NJ (United States); Heusner, Till [University of Duisburg/Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2010-12-15

    Renal radioiodine excretion is {proportional_to}50% faster during euthyroidism versus hypothyroidism. We therefore sought to assess lesion dose/GBq of administered {sup 131}I activity (LDpA) in iodine-avid metastases (IAM) of differentiated thyroid carcinoma (DTC) in athyreotic patients after recombinant human thyroid-stimulating hormone (rhTSH) versus after thyroid hormone withdrawal (THW). We retrospectively compared mean LDpA between groups of consecutive patients (N = 63) receiving {sup 124}I positron emission tomography/computed tomography ({sup 124}I PET/CT) aided by rhTSH (n = 27) or THW (n = 36); we prospectively compared LDpA after these stimulation methods within another individual. Data derived from serial PET scans and one CT scan performed 2-96 h post-{sup 124}I ingestion. A mixed model analysis of covariance (ANCOVA) calculated the treatment groups' mean LDpAs adjusting for statistically significant baseline intergroup differences: non-IAM were more prevalent, median IAM count/patient lower in cervical lymph nodes and higher in distant sites, median stimulated thyroglobulin higher, mean cumulative radioiodine activity greater and prior diagnostic scintigraphy more frequent in the rhTSH patients. Mean LDpAs were: rhTSH group (n = 71 IAM), 30.6 Gy/GBq; THW group (n = 66 IAM), 51.8 Gy/GBq. The difference in group means (rhTSH less THW), -21.2 Gy/GBq, was statistically non-significant (p = 0.1667). However, the 95% confidence interval of that difference (-51.4 to + 9 Gy/GBq) suggested a trend favouring THW. The within-patient comparison found 2.9- to 10-fold higher LDpAs under THW. We found some suggestions, but no statistically significant evidence, that rhTSH administration results in a lower radiation dose to DTC metastases than does THW. A large, well-controlled, prospective within-patient study should resolve this issue. (orig.)

  2. HiLo: Multicentre randomized phase III clinical trial of high vs low dose radioiodine, with or without recombinant human thyroid stimulating hormone (rhTSH), for remnant ablation for differentiated thyroid cancer

    Mallick, U. [Freeman Hospital, Newcastle, Newcastle upon Tyne (United Kingdom); Harmer, C.; Clarke, S.; Moss, L.; Nicol, A.; Clarke, P.; Smellie, J.; McCready, R.; Farnell, K.; Franklyn, J.; John, R.; Nutting, C.; Yap, B.; Lemon, C.; Wadlsey, J.; Gerrard, G.; Roques, T.; Macias, E.; Whitaker, S.; Abdul-Hamid, A.; Alvarez, P.; Kadalayil, L.; Hackshaw, A.

    2012-07-01

    Recommended treatment for most patients with differentiated thyroid cancer is surgery followed by radioiodine ablation. Current practice in many centres is to use a high administered activity of 3.7 GBq (100 mCi). However, a lower activity (1.1 GBq or 30 mCi) has advantages including a shorter stay in hospital isolation and lower risk of side effects, including the risk of a second cancer. Also, Thyrogen (rhTSH) allows patients to continue thyroid hormone replacement during ablation, avoiding symptoms of hypothyroidism and also reduces total body radiation dose. We conducted a large randomized factorial multi centre trial to simultaneously address whether ablation success rates are similar using (i) either 1.1 GBq or 3.7 GBq, and (ii) either Thyrogen or thyroid hormone withdrawal. It is the first ever national prospective trial in thyroid cancer in the UK. Final results will be available in 2011

  3. Dose absorbed in adults and children thyroid due to the I123 using the dosimetry MIRD and Marinelli

    Using the dosimetry MIRD, and representation Cristy-Eckerman in the thyroid gland and organs of their bio-kinetics when I123 (Iodine) is used, the study demonstrates that the absorbed dose by the gland of an adult, children, and newly born, is their auto-dose, independent of the compartments number of their bio-kinetics. The dosimetric contributions of the organs of their bio-kinetics are insignificant. Their results are not significantly different to those obtained by the formalism MARINELLI (auto-dose) when it uses a sphere like glandular representation. In consequence, the kinetic model corresponding to the glandular representation decreases to a compartment, where the gland can also be represented like a sphere. (Author)

  4. Added value of SPECT/CT in addition to whole-body scintigraphy augmented with prone lateral views in patients with well-differentiated thyroid carcinoma

    ATASAYAR N.

    2014-01-01

    Purpose: We aimed to determine the impact of SPECT/CT performed in addition to whole-­‐body scintigraphy augmented with prone lateral views in patients with well-­‐differentiated thyroid carcinoma. Methods and Materials: This retrospective study included 141 patients (87 female, 54 male, mean age 47 years) with well-­‐differentiated thyroid carcinoma (105 papillary, 31 follicular, 1 Hürthle cell and 4 poorly differentiated) treated with radioiodine therapy (1000-7400 MBq). P...

  5. Detection for residual thyroid tissue and metastatic lesion after total thyroidectomy in patients with differentiated thyroid cancer: comparison between Tc-99m pertechnetate scan and high dose I-131 therapy scan

    To evaluate diagnostic sensitivity of nuclear imaging in the detection of residual thyroid tissue and metastatic lesion, we have compared neck scintigrams with Tc-99m pertechnetate (Tc-99m scan) and high dose I-131 iodide (I-131 scan) in patients with differentiated thyroid cancer. One hundred thirty-five thyroidectomized patients for differentiated thyroid cancer were enrolled in this study. Twenty-three had a previous history of radioiodine therapy. Planar and pin-hole images of anterior neck with Tc-99m were acquired at 20 minutes after injection, followed by I-131 scan three days after high-dose radioiodine therapy with 7 days interval. Patients were asked to discontinue thyroid hormone replacement more than 4 weeks. All subjects were in hypothyroid state. Seventy out of 135 patients (51.9%) showed concordant findings between Tc-99m and I-131 scan. Tc-99m scan did not show any uptake in thyroid bed in 11 of 112 patients without previous history of radioiodine therapy, but 9 of them showed bed uptake in I-131 scan. Tc-99m scan showed no bed uptake in all of the 23 patients with previous history of radioiodine therapy, in contrast 14 of them (60.9%) showed bed uptake in I-131 scan. These results suggest that Tc-99m scan has poor detectability for residual thyroid tissue or metastatic lesion in thyroidectomized differentiated thyroid cancer patients, compared to high dose I-131 therapy scan. Tc-99m scan could not detect any remnant tissue or metastatic lesion in patients with previous history of radioiodine treatment, especially

  6. Detection for residual thyroid tissue and metastatic lesion after total thyroidectomy in patients with differentiated thyroid cancer: comparison between Tc-99m pertechnetate scan and high dose I-131 therapy scan

    Lee, Joo Ryung; Ahn, Byeong Cheol; Jeong, Shin Young; Lee, Fae Tae; Lee, Kyu Bo [Kyungpook National University Medical School, Daegu (Korea, Republic of)

    2003-04-01

    To evaluate diagnostic sensitivity of nuclear imaging in the detection of residual thyroid tissue and metastatic lesion, we have compared neck scintigrams with Tc-99m pertechnetate (Tc-99m scan) and high dose I-131 iodide (I-131 scan) in patients with differentiated thyroid cancer. One hundred thirty-five thyroidectomized patients for differentiated thyroid cancer were enrolled in this study. Twenty-three had a previous history of radioiodine therapy. Planar and pin-hole images of anterior neck with Tc-99m were acquired at 20 minutes after injection, followed by I-131 scan three days after high-dose radioiodine therapy with 7 days interval. Patients were asked to discontinue thyroid hormone replacement more than 4 weeks. All subjects were in hypothyroid state. Seventy out of 135 patients (51.9%) showed concordant findings between Tc-99m and I-131 scan. Tc-99m scan did not show any uptake in thyroid bed in 11 of 112 patients without previous history of radioiodine therapy, but 9 of them showed bed uptake in I-131 scan. Tc-99m scan showed no bed uptake in all of the 23 patients with previous history of radioiodine therapy, in contrast 14 of them (60.9%) showed bed uptake in I-131 scan. These results suggest that Tc-99m scan has poor detectability for residual thyroid tissue or metastatic lesion in thyroidectomized differentiated thyroid cancer patients, compared to high dose I-131 therapy scan. Tc-99m scan could not detect any remnant tissue or metastatic lesion in patients with previous history of radioiodine treatment, especially.

  7. Alterations of Thyroid Morphology and Function After Long-Term Exposure to Low Doses of Endocrine Disruptor Dichlorodiphenyltrichloroethane

    Yaglov V.V.; Yaglova N.V.

    2014-01-01

    The aim of the investigation was to evaluate changes in thyroid morphology and function after different long-term exposure to low doses of endocrine disruptor dichlorodiphenyltrichloroethane (DDT) under the maximum permissible levels in food products. Materials and Methods. The experiment was performed on adult male Wistar rats (n=62). Drinking water was substituted for water solution of o,p-DDT 20 and 80 μg/L. Mean daily consumption of DDT was 1.89±0.86 and 7.77±0.17 µg/kg body weight, r...

  8. GATE based Monte Carlo simulation of planar scintigraphy to estimate the nodular dose in radioiodine therapy for autonomous thyroid adenoma

    The recommended target dose in radioiodine therapy of solitary hyperfunctioning thyroid nodules is 300-400 Gy and therefore higher than in other radiotherapies. This is due to the fact that an unknown, yet significant portion of the activity is stored in extranodular areas but is neglected in the calculatory dosimetry. We investigate the feasibility of determining the ratio of nodular and extranodular activity concentrations (uptakes) from post-therapeutically acquired planar scintigrams with Monte Carlo simulations in GATE. The geometry of a gamma camera with a high energy collimator was emulated in GATE (Version 5). A geometrical thyroid-neck phantom (GP) and the ICRP reference voxel phantoms 'Adult Female' (AF, 16 ml thyroid) and 'Adult Male' (AM, 19 ml thyroid) were used as source regions. Nodules of 1 ml and 3 ml volume were placed in the phantoms. For each phantom and each nodule 200 scintigraphic acquisitions were simulated. Uptake ratios of nodule and rest of thyroid ranging from 1 to 20 could be created by summation. Quantitative image analysis was performed by investigating the number of simulated counts in regions of interest (ROIs). ROIs were created by perpendicular projection of the phantom onto the camera plane to avoid a user dependant bias. The ratio of count densities in ROIs over the nodule and over the contralateral lobe, which should be least affected by nodular activity, was taken to be the best available measure for the uptake ratios. However, the predefined uptake ratios are underestimated by these count density ratios: For an uptake ratio of 20 the count ratios range from 4.5 (AF, 1 ml nodule) to 15.3 (AM, 3 ml nodule). Furthermore, the contralateral ROI is more strongly affected by nodular activity than expected: For an uptake ratio of 20 between nodule and rest of thyroid up to 29% of total counts in the ROI over the contralateral lobe are caused by decays in the nodule (AF 3 ml). In the case of the 1 ml nodules this effect is smaller: 9

  9. GATE based Monte Carlo simulation of planar scintigraphy to estimate the nodular dose in radioiodine therapy for autonomous thyroid adenoma

    Hammes, Jochen; Schmidt, Matthias; Schicha, Harald; Eschner, Wolfgang [Universitaetsklinikum Koeln (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Pietrzyk, Uwe [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Neurowissenschaften und Medizin (INM-4); Wuppertal Univ. (Germany). Fachbereich C - Physik

    2011-07-01

    The recommended target dose in radioiodine therapy of solitary hyperfunctioning thyroid nodules is 300-400 Gy and therefore higher than in other radiotherapies. This is due to the fact that an unknown, yet significant portion of the activity is stored in extranodular areas but is neglected in the calculatory dosimetry. We investigate the feasibility of determining the ratio of nodular and extranodular activity concentrations (uptakes) from post-therapeutically acquired planar scintigrams with Monte Carlo simulations in GATE. The geometry of a gamma camera with a high energy collimator was emulated in GATE (Version 5). A geometrical thyroid-neck phantom (GP) and the ICRP reference voxel phantoms 'Adult Female' (AF, 16 ml thyroid) and 'Adult Male' (AM, 19 ml thyroid) were used as source regions. Nodules of 1 ml and 3 ml volume were placed in the phantoms. For each phantom and each nodule 200 scintigraphic acquisitions were simulated. Uptake ratios of nodule and rest of thyroid ranging from 1 to 20 could be created by summation. Quantitative image analysis was performed by investigating the number of simulated counts in regions of interest (ROIs). ROIs were created by perpendicular projection of the phantom onto the camera plane to avoid a user dependant bias. The ratio of count densities in ROIs over the nodule and over the contralateral lobe, which should be least affected by nodular activity, was taken to be the best available measure for the uptake ratios. However, the predefined uptake ratios are underestimated by these count density ratios: For an uptake ratio of 20 the count ratios range from 4.5 (AF, 1 ml nodule) to 15.3 (AM, 3 ml nodule). Furthermore, the contralateral ROI is more strongly affected by nodular activity than expected: For an uptake ratio of 20 between nodule and rest of thyroid up to 29% of total counts in the ROI over the contralateral lobe are caused by decays in the nodule (AF 3 ml). In the case of the 1 ml nodules this

  10. Dose selection for radioiodine therapy of borderline hyperthyroid patients with multifocal and disseminated autonomy on the basis of 99mTc-pertechnetate thyroid uptake

    The aim of this study was to optimise radioiodine therapy of diffuse and nodular toxic goitre by calculation of the radiation dose delivered to the thyroid on the basis of the pretreatment technetium-99m pertechnetate thyroid uptake under thyrotropin suppression (TcTUs). The TcTUs value serves as a substitute for the non-suppressible iodine turnover and the functional autonomous mass. Marinelli's formula was used to calculate tissue absorbed doses of 150 Gy, 200 Gy, 250 Gy and 300 Gy to the thyroids of 438 patients with multifocal and disseminated autonomy. The mean age of patients was 70±9 years, and the mean thyroid volume was 54±26 ml. Two hundred and sixty-one of the patients had at least one documented previous episode of overt hyperthyroidism. Tissue absorbed doses were adapted to the pretreatment TcTUs: 150 Gy for a TcTUs of 1.5%-2.49%, 200 Gy for a TcTUs of 2.5%-3.49%, 250 Gy for a TcTUs of 3.5%-4.49% and 300 Gy for a TcTUs of ≥4.5%. Normalisation of TcTUs and thyrotropin (TSH), thyroid volume reduction and frequency of hypothyroidism and recurrent hyperthyroidism were evaluated 1 year after a single radioiodine therapy. The presented dose strategy resulted in normalisation of TcTUs in 96% and an increase in TSH to the normal range in 92%. Recurrent hyperthyroidism was observed in only five patients. Thyroid volume decreased from 54±26 before treatment to 34±20 ml, a mean reduction of 37%. The frequency of hypothyroidism, at 0.9%, was encouragingly low. Dose selection in accordance with pretreatment TcTUs can be recommended for elimination of functional autonomous tissue with a single radioiodine therapy in patients of advanced age with enlarged thyroid glands and relevant autonomous masses who are at risk of developing iodine-induced hyperthyroidism. (orig.)

  11. Radioiodine therapy in Graves' disease based on tissue-absorbed dose calculations: effect of pre-treatment thyroid volume on clinical outcome

    This study was performed with three aims. The first was to analyse the effectiveness of radioiodine therapy in Graves' disease patients with and without goitres under conditions of mild iodine deficiency using several tissue-absorbed doses. The second aim was to detect further parameters which might be predictive for treatment outcome. Finally, we wished to determine the deviation of the therapeutically achieved dose from that intended. Activities of 185-2,220 MBq radioiodine were calculated by means of Marinelli's formula to deliver doses of 150, 200 or 300 Gy to the thyroids of 224 patients with Graves' disease and goitres up to 130 ml in volume. Control of hyperthyroidism, change in thyroid volume and thyrotropin-receptor antibodies were evaluated 15±9 months after treatment for each dose. The results were further evaluated with respect to pre-treatment parameters which might be predictive for therapy outcome. Thyroidal radioiodine uptake was measured every day during therapy to determine the therapeutically achieved target dose and its coefficient of variation. There was a significant dose dependency in therapeutic outcome: frequency of hypothyroidism increased from 27.4% after 150 Gy to 67.7% after 300 Gy, while the frequency of persistent hyperthyroidism decreased from 27.4% after 150 Gy to 8.1% after 300 Gy. Patients who became hypothyroid had a maximum thyroid volume of 42 ml and received a target dose of 256±80 Gy. The coefficient of variation for the achieved target dose ranged between 27.7% for 150 Gy and 17.8% for 300 Gy. When analysing further factors which might influence therapeutic outcome, only pre-treatment thyroid volume showed a significant relationship to the result of treatment. It is concluded that a target dose of 250 Gy is essential to achieve hypothyroidism within 1 year after radioiodine therapy in Graves' disease patients with goitres up to 40 ml in volume. Patients with larger goitres might need higher doses. (orig.)

  12. Efficacy of high therapeutic doses of iodine-131 in patients with differentiated thyroid cancer and detectable serum thyroglobulin

    Keizer, B. de; Rijk, P.P. van; Klerk, J.M.H. de [Dept. of Nuclear Medicine, University Medical Center Utrecht (Netherlands); Koppeschaar, H.P.F.; Zelissen, P.M.J.; Lips, C.J.M. [Dept. of Endocrinology, University Medical Center Utrecht (Netherlands); Dijk, A. van [Dept. of Hospital Pharmacy, University Medical Center Utrecht (Netherlands)

    2001-02-01

    Serum thyroglobulin (Tg) is usually the best marker of residual or metastatic disease after treatment of differentiated thyroid cancer. We evaluated the effect of so-called blind therapeutic doses of iodine-131 in patients with detectable Tg during suppressive levothyroxine treatment (Tg-on), and in patients with a negative diagnostic scintigram but detectable Tg during the hypothyroid phase (Tg-off). Twenty-two patients with differentiated thyroid carcinoma underwent total thyroidectomy and radioiodine ablation. During the follow-up, six patients with detectable Tg-on and 16 patients with detectable Tg-off were identified. All patients were treated with a blind therapeutic dose of 7,400 MBq iodine-131. Diagnostic scintigrams were compared with post-treatment scintigrams. Tg-off was measured in 16 cases, 1 year after the administration of the blind therapeutic dose, at the time of the follow-up diagnostic scintigram. Six patients were followed up by Tg-on only. Post-therapy scintigrams revealed previously undiagnosed local recurrence or distant metastases in 13/22 cases (59%); the remaining nine post-therapy scintigrams were negative. At the time of the blind therapeutic doses, Tg-off values ranged from 8 to 608 {mu}g/l. After 1 year of follow-up, Tg-off decreased in 14/16 (88%) patients. In all patients who were followed by Tg-on only (n=6), a decrease in Tg values was measured. It is concluded that blind therapeutic doses resulted in a decrease in Tg levels in the majority of patients with suspected recurrence or metastases. The post-treatment scintigrams revealed pathological uptake in 59% of patients. (orig.)

  13. A Novel Approach for Evaluating Carbamate Mixtures for Dose Additivity

    Two mathematical approaches were used to test the hypothesis ofdose-addition for a binary and a seven-chemical mixture ofN-methyl carbamates, toxicologically similar chemicals that inhibit cholinesterase (ChE). In the more novel approach, mixture data were not included in the ana...

  14. A mathematical approach to optimal selection of dose values in the additive dose method of ERP dosimetry

    Additive dose methods commonly used in electron paramagnetic resonance (EPR) dosimetry are time consuming and labor intensive. We have developed a mathematical approach for determining optimal spacing of applied doses and the number of spectra which should be taken at each dose level. Expected uncertainitites in the data points are assumed to be normally distributed with a fixed standard deviation and linearity of dose response is also assumed. The optimum spacing and number of points necessary for the minimal error can be estimated, as can the likely error in the resulting estimate. When low doses are being estimated for tooth enamel samples the optimal spacing is shown to be a concentration of points near the zero dose value with fewer spectra taken at a single high dose value within the range of known linearity. Optimization of the analytical process results in increased accuracy and sample throughput

  15. A mathematical approach to optimal selection of dose values in the additive dose method of ERP dosimetry

    Hayes, R.B.; Haskell, E.H.; Kenner, G.H. [Utah Univ., Salt Lake City, UT (United States)

    1996-01-01

    Additive dose methods commonly used in electron paramagnetic resonance (EPR) dosimetry are time consuming and labor intensive. We have developed a mathematical approach for determining optimal spacing of applied doses and the number of spectra which should be taken at each dose level. Expected uncertainitites in the data points are assumed to be normally distributed with a fixed standard deviation and linearity of dose response is also assumed. The optimum spacing and number of points necessary for the minimal error can be estimated, as can the likely error in the resulting estimate. When low doses are being estimated for tooth enamel samples the optimal spacing is shown to be a concentration of points near the zero dose value with fewer spectra taken at a single high dose value within the range of known linearity. Optimization of the analytical process results in increased accuracy and sample throughput.

  16. Radiation and host factors in human thyroid tumors following thymus irradiation

    Thyroid tumor data from the 1971 survey of the Rochester, New York thymus irradiated population are further analyzed to study radiobiological and host factors. The analyses were based on the approx. 2650 irradiated subjects and 4800 sibling controls who had 5 or more years of follow-up. Twenty-four thyroid cancers and 52 thyroid adenomas were found in the irradiated group, and O thyroid cancers and 6 adenomas among the controls. The overall risk estimates were 3.8 thyroid cancers/106persons/yr/rad and 4.5 thyroid adenomas/106 persons/yr/rad. The dose-response data (thyroid dose range of 5 to > 1000 rad) for thyroid cancer indicate both a linear and a dose-squared component, but no dose-squared component is evident for thyroid adenomas. At lower total doses (< 400 rad) there was a suggestion that dose fractionation diminished the thyroid cancer response, but a similar fractionation effect was not found for thyroid adenomas. The temporal pattern of tumors suggested an extended plateau of excess tumor production, rather than a wavelike temporal pattern. There was no evidence for an inverse relationship between thyroid radiation dose and thyroid cancer latency. Female and Jewish subjects had a higher risk of radiation-induced thyroid cancer than did their respective counterparts. The additive and multiplicative models of radiation effects were compared with respect to sex differences; neither model provided a superior fit to the data. The tentative nature of the conclusions is stressed because of the relatively small number of thyroid cancers. (author)

  17. Marginal Iodide Deficiency and Thyroid Function: Dose-response analysis for quantitative pharmacokinetic modeling

    Severe iodine deficiency is known to cause adverse health outcomes and remains a benchmark for understanding the effects of hypothyroidism. However, the implications of marginal iodine deficiency on function of the thyroid axis remain less well known. The current study examined t...

  18. Derivation of the critical effect size/benchmark response for the dose-response analysis of the uptake of radioactive iodine in the human thyroid.

    Weterings, Peter J J M; Loftus, Christine; Lewandowski, Thomas A

    2016-08-22

    Potential adverse effects of chemical substances on thyroid function are usually examined by measuring serum levels of thyroid-related hormones. Instead, recent risk assessments for thyroid-active chemicals have focussed on iodine uptake inhibition, an upstream event that by itself is not necessarily adverse. Establishing the extent of uptake inhibition that can be considered de minimis, the chosen benchmark response (BMR), is therefore critical. The BMR values selected by two international advisory bodies were 5% and 50%, a difference that had correspondingly large impacts on the estimated risks and health-based guidance values that were established. Potential treatment-related inhibition of thyroidal iodine uptake is usually determined by comparing thyroidal uptake of radioactive iodine (RAIU) during treatment with a single pre-treatment RAIU value. In the present study it is demonstrated that the physiological intra-individual variation in iodine uptake is much larger than 5%. Consequently, in-treatment RAIU values, expressed as a percentage of the pre-treatment value, have an inherent variation, that needs to be considered when conducting dose-response analyses. Based on statistical and biological considerations, a BMR of 20% is proposed for benchmark dose analysis of human thyroidal iodine uptake data, to take the inherent variation in relative RAIU data into account. Implications for the tolerated daily intakes for perchlorate and chlorate, recently established by the European Food Safety Authority (EFSA), are discussed. PMID:27268963

  19. Cancer and non-cancer diseases of the thyroid gland and their dose dependence in children and adolescents affected as a result of the Chernobyl accident

    Over 30,000 children and adolescents from four rayons of Brayansk oblast and from three rayons of Kaluga oblast have been examined. The cohort is being followed up dynamically. An age dependence of the radiation doses to the thyroid was clearly detected. The largest doses were found to be in children under 3 years old. Three per cent of children received doses above 200 cGy. 5 refs, 1 fig., 1 tab

  20. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident: The Fukushima health management survey.

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-08-01

    The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, nuclear accident. PMID:27583855

  1. Thyroid dose of I-131 absorbed by the internal organs of a pregnant woman; Dosis tiroidea de I-131 absorbida por los organos internos de una embarazada

    Arcos P, A.; Manzanares A, E.; Vega C, H.R.; Leon, C.L. de [Cuerpo Academico de Radiobiologia de la Universidad Autonoma de Zacatecas (Mexico)]. e-mail: emanz_44@yahoo.com

    2007-07-01

    The use of nuclear techniques, for diagnosis or treatment, generates stress in the patient and its relatives. During the pregnancy some sufferings related with the thyroid gland can be presented. If the patient is pregnant, OEP or NOEP, the stress comes from the fear to that the product can it turns affected. The dose is calculated that the Iodine 131, captured by the thyroid of a woman with three months of pregnancy, it deposits in the brain, stomach, heart, kidneys, liver, lungs, ovaries, pancreas, thymus, spleen and in the uterus. The thymus is the organ that receives the biggest dose. (Author)

  2. Thyroid effects

    Risk coefficients for thyroid disorders have been developed for both 131I and external x or gamma low-LET radiation. A linear, no-threshold model has been used for thyroid neoplasms. A linear, threshold model has been used for other thyroid disorders. Improvements since the Reactor Safety Study were made possible by relevant new animal and human data. Major changes are as follows. Animal data are used to supplement the human experience where necessary. A specific risk estimate model is used for thyroid neoplasms, which accounts for observed effects of gender and age at exposure on risk. For thyroid cancer, the basis of the risk coefficients is the experience of North Americans following x-irradiation for benign disease in childhood. This recognizes possible differences in susceptibility in people of different heritage. A minimum induction period for thyroid neoplasms following irradiation is used to define periods at risk. An upper bound risk coefficient for cancer induction following exposure to 131I is based on human experience at relatively low dose exposures. While the overall lifetime risks of death due to thyroid cancer are consistent with projections by the ICRP, BEIR III, and UNSCEAR Reports, the current model permits greater flexibility in determining risk for population subgroups. 88 references, 8 tables

  3. Dose in the uterus of a woman, with three months of pregnancy, due to the 131 I accumulated in her thyroid gland

    In this study the absorbed dose by the uterus of a woman with three months of pregnancy to who was applied a dose of 131 I that was accumulated in the thyroid gland is determined. The absorbed dose was obtained by means of Monte Carlo calculations developing a detailed three-dimensional model of the pregnant one, where they have been included most of the organs. The absorbed dose also was calculated by means of a simple procedure. To verify the calculated results it was carried out an experiment where was constructed a phantom of the neck, in this was included the thyroid with 131 I and the exposure was measured at different distances of the neck; this was related with the dose. Of the Monte Carlo calculation is obtained that for each mCi of 131 I that is retained in the mother's thyroid, the uterus absorbs a dose of 6.80 E(-11) Gy. When comparing the results, it was found that the simple calculation throws a result 29 times superior to that of the dose obtained by means of Monte Carlo. When applying a correction for the effect of the absorption of the gamma photons by the mother's body an absorbed dose in the uterus was obtained that is 0.16 times superior to the Monte Carlo calculation. Of the experimental phase it is verified that the values calculated by means of the simple method are equal to those experimentally measured. (Author)

  4. Thyroid scan

    ... PET scan Skin nodules Thyroid cancer Thyroid cancer - medullary carcinoma Thyroid cancer - papillary carcinoma Toxic nodular goiter ... Topics Hyperthyroidism Hypothyroidism Nuclear Scans Thyroid Cancer Thyroid Diseases Thyroid Tests Browse the Encyclopedia A.D.A. ...

  5. Validation of 131I ecological transfer models and thyroid dose assessments using Chernobyl fallout data from the Plavsk district, Russia

    Zvonova, I.; Krajewski, P.; Berkovsky, V.; Ammann, M.; Duffa, C.; Filistovic, V.; Homma, T.; Kanyar, B.; Nedveckaite, T.; Simon, S.L.; Vlasov, O.; Webbe-Wood, D.

    2009-01-01

    Within the project “Environmental Modelling for Radiation Safety” (EMRAS) organized by the IAEA in 2003 experimental data of 131I measurements following the Chernobyl accident in the Plavsk district of Tula region, Russia were used to validate the calculations of some radioecological transfer models. Nine models participated in the inter-comparison. Levels of 137Cs soil contamination in all the settlements and 131I/137Cs isotopic ratios in the depositions in some locations were used as the main input information. 370 measurements of 131I content in thyroid of townspeople and villagers, and 90 measurements of 131I concentration in milk were used for validation of the model predictions. A remarkable improvement in models performance comparing with previous inter-comparison exercise was demonstrated. Predictions of the various models were within a factor of three relative to the observations, discrepancies between the estimates of average doses to thyroid produced by most participant not exceeded a factor of ten. PMID:19783331

  6. Increasing doses effect of L-T4 and L-T3 in the hypothalamus - hypophysis - thyroid in patients carrier of congenital and acquired hypothyroidism

    The pituitary and peripheral response to L-T4 and L-T3 therapy were studied in 12 patients with congenital goitrous hypothyroidism, in 10 patients with an ectopic thyroid and onset of hypothyroidism at 3-8 years of age, and in 6 patients with adult-onset hypothyroidism, after they had had their chronic thyroid hormone replacement therapy discontinued for 30 days. They were first treated with increasing L-T4 (0.1, 0.2, and 0.4 mg daily) followed by L-T3 (0.05 and 0.2 mg daily) after stopping thyroid medication for another month. Ten normal subjects were treated identically. Since all patients received similar doses of thyroid hormones (μg/Kg of body weight) and had similar serum levels of T4 and T3 on each dose of L-T4 or L-T3, this paper concludes that congenitally hypothyroid patients have persistent pituitary resistance, but no peripheral resistance, to thyroid hormone. (author)

  7. Uncertainty of the thyroid dose assessment of Belarus population by iodine-131 after the Chernobyl accident derived with method of radioecological modeling

    The every result of radioecological modeling is connecting with uncertainty. The realization of analyze of uncertainty allows to assess the reliability of dose estimation. For this purpose Monte-Carlo method was used. Accordingly to function of probability density for each parameter, using Latin hypercube sampling method, the value was generated. Based on derived quantities dose estimation was made. The uncertainty analyze showed, that the density function of likelihood for average thyroid dose estimation on settlement level is the curve of lognormal distribution. In this case the uncertainty factor was defined with the geometric standard deviation of result and it amounted 3.1 for dry and 3.3 for wet deposition. These values of uncertainty factor are considered as moderate values and thyroid dose assessments are characterized by average degree of reliability (author)

  8. Absorbed body dose simulation in Thyroid cancer therapy using MCNP4Cand ITScodes and comparison to experimental results

    Two standard particle transport codes of MCNP4C and integrated tiger series were used to estimate the total body dose in a thyroid cancer therapy study, with I-131 as the radionuclide source. Human body was modeled by water and soft tissue ellipsoids. Phantoms' dimensions were selected according to Brow nell recommendation. Absorbed fractions were calculated by both codes for different phantoms and for gammas with 0.364 MeV energy, which has the highest fraction in I-131 emitting gammas. Results were compared to the data published by Brow nell et.al.. Figure 1 shows the results of MCNP4C and Integrated Tiger Series with results published by Brow nell et. al.

  9. Clinical Usefulness between High Dose Radioiodine Therapy and Helicobacter Pylori Infection after Total Thyroidectomy due to Well Differentiated Thyroid Cancer

    Yun, Kuk No; Lim, Seok Tae; Moon, Eun Ha; Kim, Jin Suk; Jeong, Young Jin; Kim, Dong Wook; Jeong, Hwan Jeong; Sohn, Myung Hee [Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of)

    2009-12-15

    Helicobacter (H) pylori infection has been considered the most important cause of gastritis, dyspepsia, and gastroduodenal ulcer. Radioiodine can be accumulated in the remaining thyroid tissue, salivary gland, and stomach. We investigated if the high radiation induced by radioiodine in the stomach after high dose radioiodine therapy (HD-RIT) is effective in the eradication of H. pylori infection. One hundred ninety nine patients (M:F=33:166, age 46.7{+-}12.3 years) who had HD-RIT (dose 159.1{+-}25.9 mCi, range 120-250 mCi) after thyroidectomy due to well differentiated thyroid cancer were enrolled. To detect H. pylori infection, the urea breath tests (UBT) were performed at 1 hour before HD-RIT and at 4 weeks after HD-RIT. The results of UBT were classified as positive ({>=}50 dpm) or negative (<50 dpm), and analyzed its values. Of 199 patients, 103 (51.8%) patients had positive UBT before HD-RIT. Of these, 80 patients had follow-up UBT after HD-RIT. Among them, 76 (95.0%) patients had persistent positive UBT and only 4 (5.0%) patients were changed negative UBT. Among 76 patients with persistent positive UBT, 26 (34.2%) patients had increased the values of follow-up UBT, 49 (64.5%) had decreased them, and 1 (1.3%) had shown the same value. The different values of UBT between before and after HD-RIT were 62{+-}66.1 dpm in increased one of follow-up UBT, and 153.3{+-}157.1 dpm in decreased one of follow-up UBT. We conclude that the radiation induced by HD-RIT is ineffective in the eradication of H. pylori infection. However, it could be influential the degree or distribution of H. pylori infection.

  10. Clinical Usefulness between High Dose Radioiodine Therapy and Helicobacter Pylori Infection after Total Thyroidectomy due to Well Differentiated Thyroid Cancer

    Helicobacter (H) pylori infection has been considered the most important cause of gastritis, dyspepsia, and gastroduodenal ulcer. Radioiodine can be accumulated in the remaining thyroid tissue, salivary gland, and stomach. We investigated if the high radiation induced by radioiodine in the stomach after high dose radioiodine therapy (HD-RIT) is effective in the eradication of H. pylori infection. One hundred ninety nine patients (M:F=33:166, age 46.7±12.3 years) who had HD-RIT (dose 159.1±25.9 mCi, range 120-250 mCi) after thyroidectomy due to well differentiated thyroid cancer were enrolled. To detect H. pylori infection, the urea breath tests (UBT) were performed at 1 hour before HD-RIT and at 4 weeks after HD-RIT. The results of UBT were classified as positive (≥50 dpm) or negative (<50 dpm), and analyzed its values. Of 199 patients, 103 (51.8%) patients had positive UBT before HD-RIT. Of these, 80 patients had follow-up UBT after HD-RIT. Among them, 76 (95.0%) patients had persistent positive UBT and only 4 (5.0%) patients were changed negative UBT. Among 76 patients with persistent positive UBT, 26 (34.2%) patients had increased the values of follow-up UBT, 49 (64.5%) had decreased them, and 1 (1.3%) had shown the same value. The different values of UBT between before and after HD-RIT were 62±66.1 dpm in increased one of follow-up UBT, and 153.3±157.1 dpm in decreased one of follow-up UBT. We conclude that the radiation induced by HD-RIT is ineffective in the eradication of H. pylori infection. However, it could be influential the degree or distribution of H. pylori infection

  11. Dose-Response Analysis of Developmental Iodide Deficiency: Reductions in Thyroid Hormones and Impaired Hippocampal Synaptic Transmission

    Iodide is an essential nutrient for thyroid hormone synthesis and severe iodide deficiency (ID) during early development is associated with neurological impairments. Several environmental contaminants can perturb the thyroid axis and this perturbation may be more acute under cond...

  12. Statistical approach for analysis of the credibility of high thyroid dose estimates based on in-vivo measurements of 131I thyroidal content for Belarusian population following the Chernobyl accident

    Exposure to thyroid for the population living in the affected countries was recognized to be one of the most significant radiological consequences of the Chernobyl accident. During the first few weeks following the accident many people in the contaminated areas were monitored for in-vivo 131I thyroidal content. Estimates of individual dose based on these in-vivo measurements for about 126,000 Belarusian residents were found to be in a wide range of up to several tens of gray. A question was raised whether the high dose estimates derived from in-vivo measurements of 131I thyroidal content are credible or should be considered as errors. The purpose of this paper is to present the results of a statistical approach used to check whether the distribution of doses to others residing in the same area in Belarus was consistent with the number of measured high dose estimates, defined as greater than 10 Gy. Dose distributions are frequently observed to be approximately lognormal, and are characterized by their geometric mean and geometric standard deviation calculated for the set of individual doses considered. Ten groups of children for six residence locations with sufficient number of high doses were analyzed (for some locations children were divided into two groups: aged 0 to 7 and 8 to 18). Out of a total number of 331 estimates of doses exceeding 10 Gy observed, 285 estimates were used in the statistical analysis. The other 46 estimates (not retained for analysis) are related to adults (14 estimates) and children (32 estimates) from various areas with small statistics. In nine groups the numbers of children with dose exceeding 10 Gy were found to be somewhat lower than expected from a lognormal distribution; in one group the number observed was equal to what was expected. Use of a statistical approach in the analysis indirectly supports the conclusion that the numbers of high thyroid dose estimates for Belarusian population are reasonably consistent with expectations

  13. Statistical aspects of reconstructing the 131I dose to the thyroid of individuals living near the Hanford Site in the mid-1940s

    In 1988 the Hanford Environmental Dose Reconstruction Project was established to estimate (reconstruct) potential doses that may have been received by individuals from radionuclides emitted with air and water effluents from the Hanford Site in southeastern Washington State, USA, since 1944. This paper discusses some of the statistical methods being developed to assess the uncertainty in reconstructed doses to the thyroid from 131I via the air-pasture-cow-milk-human pathway in the 1944--47 period. Emphasis is placed on assessing dose uncertainties that arise from uncertainties in specification of model parameters. 7 refs

  14. Quantitative study about influence of 131I diagnostic dose on uptake of 131I for differentiated thyroid carcinoma

    There are 52 patients with DTC who were referred to our department for radioiodine ablation for the first time were adopted. 30 patients (experimental group) were given a diagnostic scan (Dscan) 24 hours after the administration of 74 MBq 131I before radioiodine therapy, and a therapeutic scan (Tscan) was performed after radioiodine therapy. The fractional concentrations of 131I in remnants or functional metastases were quantified on Dscan and Tscan, and were expressed as Dx and Tx respectively. 22 patients (control group) received 131I therapy directly after thyroidectomy. And Tscan was performed after the radioiodine ablation. As a result the mean Tx (experimental group) was lower both than Dx (experimental group) and Tx (control group). According to the interval time between the diagnostic dose and therapy dose was 1-2, 3-7 and 8-32 days, the experimental group patients were divided into three subgroups A, B, C. The mean Tx/Dx of subgroup B was lower than Tx/Dx of subgroups A and C. There was no statistically significant difference of Tx/Dx between subgroup A and C. In conclusions that 74 MBq 131I for diagnostic scan can cause thyroid stunning. And the stunning effect is more significant when the radioiodine ablation was performed on 3 to 7 days after diagnostic dose. (authors)

  15. Estimation of the resident's additional dose in bone-coal mining areas of the five provinces

    JIANG Shan; ZHANG Liang; YE Ji-Da; KONG Ling-Li; LI Ying; SHI Jin-Hua; WU Zong-Mei

    2005-01-01

    This paper introduces the resident's additional dose in bone-coal mining areas. The increase of the annual additional effective doses accepted by the residents living in the carbide-brick houses, the staffs working in the carbide-brick houses and the miners working in the bone-coal mining areas of Hubei, Hunan, Jiangxi, Zhejiang and Anhui Provinces is caused by the rising of environmental radioactive level. The investigation of natural background radiation in the bone-coal mining areas indicated that both mining and utilizing bone-coal cause the rise of environmental radioactive level. The ranges of the annual additional effective dose accepted by the residents, staffs and miners is 1.9-6.8 mSv, 0.5-2.0 mSv and 8.2-71 mSv, and with an average of 3.8 mSv, 1 mSv and 40 mSv, respectively. The annual additional effective doses accepted by part residents and staffs exceed the dose limit of 1 mSv for public exposure, and part miners exceed the dose limit of 20 mSv for occupational exposure. And the contribution of dose caused by inhaled radon to the total additional effective dose is over 76%.

  16. Estimation of the resident's additional dose in bone-coal mining areas of the five provinces

    This paper introduces the resident's additional dose in bone-coal mining areas. The increase of the annual additional effective doses accepted by the residents living in the carbide-brick houses, the staffs working in the carbide-brick houses and the miners working in the bone-coal mining areas of Hubei, Hunan, Jiangxi, Zhejiang and Anhui Provinces is caused by the rising of environmental radioactive level. The investigation of natural background radiation in the bone-coal mining areas indicated that both mining and utilizing bone-coal cause the rise of environ- mental radioactive level. The ranges of the annual additional effective dose accepted by the residents, staffs and miners is 1.9-6.8 mSv, 0.5-2.0 mSv and 8.2-71 mSv, and with an average of 3.8 mSv, 1 mSv and 40 mSv, respectively. The annual additional effective doses accepted by part residents and staffs exceed the dose limit of 1 mSv for public exposure, and part miners exceed the dose limit of 20 mSv for occupational exposure. And the contribution of dose caused by inhaled radon to the total additional effective dose is over 76%. (authors)

  17. Thyroid irradiation doses and organization of endocrinological monitoring for the population in the Ukrainian SSR after the accident at the Chernobyl Nuclear Power Station

    The paper is devoted to one of the most important aspects of the accident at the Chernobyl Nuclear Power Station: thyroid irradiation in the residents of 8 areas in the Ukrainian SSSR and the town of Pripyat, affected with radioactive iodine. Irradiation doses, prognosis of medical effects of endocrinological monitoring of the affected population were thoroughly considered. The authors proposed a scheme of health care of the population in these areas. They also discussed the structure of data bases for analysis of medicodosimetric information of iodine effects of the accident. The main trends in medicodosimetric problems of the effects of thyroid irradiation were outlined

  18. Low-dose irradiation to head, neck, or chest during infancy as a possible cause of thyroid carcinoma in teen-agers

    A matched case-control study was performed to identify the etiologic factors for thyroid carcinoma in teen-agers. Twenty-seven cases and 69 controls were investigated to assess the significance of various maternal and subject factors. Irradiation during infancy was the only factor which showed a statistically significant association with the incidence of thyroid cancer in teen-agers (summary χ2 = 8.040; d.f. = 1; P < 0.005). The estimated dose ranged from 0.2 to 40 rads on the head, neck, or chest during infancy. (author)

  19. Comparison of the Influence on the Liver Function Between Thyroid Hormone Withdrawal and rh-TSH Before High-Dose Radioiodine Therapy in Patients with Well-Differentiated Thyroid Cancer

    Han, Yeon-Hee; Lim, Seok Tae; Yun, Kuk-No; Yim, Sung Kyun; Kim, Dong Wook; Jeong, Hwan-Jeong; Sohn, Myung-Hee [Chonbuk National Univ. Medical School and Hospital, Jeonju (Korea, Republic of)

    2012-06-15

    An elevated thyroid stimulating hormone level (TSH) is essential to stimulate the uptake of radioiodine into thyroid remnants and metastases and metastases of thyroid cancer when a patient under-goes high-dose radioiodine therapy. Nowadays, recombinant human thyroid stimulating hormone (rh-TSH) is increasingly used instead of the classic method of thyroid hormone withdrawal (THW). However, beyond the therapeutic effects, clinical differences between the two methods have not yet been clearly demonstrated. The aim of this work was to investigate the effects of the two methods, especially on liver function. We identified 143 evaluable patients who were further divided into two groups: THW and rh-TSH. We first reviewed the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, which were measured during the admission period for total thyroidectomy. We called these liver enzyme levels 'base AST' and 'base ALT.' We also assessed other chemistry profiles, including AST, ALT, total cholesterol, LDL cholesterol, alkaline phosphatase (ALP), total bilirubin (TB), and triglyceride (TG), which were measured on admission day for high-dose radioiodine therapy. We called these liver enzyme levels 'follow-up AST'and 'follow-up ALT.' We compared the changes in base and follow-up liver enzyme levels and the other chemistry profiles between the two groups. The base AST and base ALT levels of the two groups were within normal range, and there was no significant difference between the two groups. In contrast to these base liver enzyme levels, follow-up AST and ALT levels than did the rh-TSH group. Patients in the THW group. Patients in the THW group also had higher levels of total cholesterol and LDL cholesterol than did the patients in the rh-TSH group. However there were no statistically significant differences in ALP, total bilirubin, and triglyceride levels between the two groups. In this retrospective analysis of liver

  20. Comparison of the Influence on the Liver Function Between Thyroid Hormone Withdrawal and rh-TSH Before High-Dose Radioiodine Therapy in Patients with Well-Differentiated Thyroid Cancer

    An elevated thyroid stimulating hormone level (TSH) is essential to stimulate the uptake of radioiodine into thyroid remnants and metastases and metastases of thyroid cancer when a patient under-goes high-dose radioiodine therapy. Nowadays, recombinant human thyroid stimulating hormone (rh-TSH) is increasingly used instead of the classic method of thyroid hormone withdrawal (THW). However, beyond the therapeutic effects, clinical differences between the two methods have not yet been clearly demonstrated. The aim of this work was to investigate the effects of the two methods, especially on liver function. We identified 143 evaluable patients who were further divided into two groups: THW and rh-TSH. We first reviewed the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, which were measured during the admission period for total thyroidectomy. We called these liver enzyme levels 'base AST' and 'base ALT.' We also assessed other chemistry profiles, including AST, ALT, total cholesterol, LDL cholesterol, alkaline phosphatase (ALP), total bilirubin (TB), and triglyceride (TG), which were measured on admission day for high-dose radioiodine therapy. We called these liver enzyme levels 'follow-up AST'and 'follow-up ALT.' We compared the changes in base and follow-up liver enzyme levels and the other chemistry profiles between the two groups. The base AST and base ALT levels of the two groups were within normal range, and there was no significant difference between the two groups. In contrast to these base liver enzyme levels, follow-up AST and ALT levels than did the rh-TSH group. Patients in the THW group. Patients in the THW group also had higher levels of total cholesterol and LDL cholesterol than did the patients in the rh-TSH group. However there were no statistically significant differences in ALP, total bilirubin, and triglyceride levels between the two groups. In this retrospective analysis of liver function, the use of rh-TSH for high-dose

  1. Evaluation of the dose absorbed by the thyroid of patients undergoing treatment of Graves disease;Avaliacao da dose absorvida pela tireoide de pacientes submetidos ao tratamento da doenca de Graves

    Costa, Tiago L.; Filho, Joao A. [Universidade Catolica de Pernambuco (UNICAP), Recife, PE (Brazil). Dept. de Fisica; Silva, Jose M.F. da [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2009-07-01

    The radioiodine is used as complementary treatment of thyroid cancer and as first choice for the treatment of Graves' disease, being efficient, safe and easy administration, but without there is a protocol defined. This work was evaluated the thyroid absorbed dose from its mass and maximum uptake of I-131 obtained in the examination of diagnostic radiology of radiotherapeutic patients undergoing treatment of Graves' disease. Based on the results, it is observed that the thyroid absorbed dose, as much in terms of mass as the maximum uptake of I-131 for different values of administered activity, varies significantly. The analysis of these parameters is an excellent indicator for the pre-define quantity of radionuclide that is administered to the patient in terms of the radiation dose required to achieve an efficient therapeutic treatment. Moreover, it was observed that the thyroid absorbed dose depends on the degree of pathology of the disease, its mass and of the maximum uptake of I-131. (author)

  2. Control and interpretation of radiometric survey data for determination of personal doses of internal exposure to the thyroid after the Chernobyl accident

    Following the Chernobyl accident one of the most important studies caused by the necessity of radiation protection and medical care of the population was determination of personal doses to residents of the territories most intensively affected by radioactive contamination. The necessity of determining personal doses demanded that a number of specific problems of measurement and dosimetry nature should be solved. In the given paper two problems are presented: determination of iodine-131 content in the thyroid by the results of radiometry of man in the presence of evenly distributed radionuclides in the body; reconstruction of doses to the thyroid in persons who had not been measured for iodine-131 content in the body or the results of their measurement proved to be unreliable

  3. Radioiodine therapy in Graves' disease based on tissue-absorbed dose calculations: effect of pre-treatment thyroid volume on clinical outcome

    Reinhardt, Michael J.; Joe, Alexius Y.; Mallek, Dirk von; Ezziddin, Samer; Palmedo, Holger [Department of Nuclear Medicine, University Hospital of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany); Brink, Ingo [Department of Nuclear Medicine, University Hospital of Freiburg (Germany); Krause, Thomas M. [Department of Nuclear Medicine, Inselspital Bern (Switzerland)

    2002-09-01

    This study was performed with three aims. The first was to analyse the effectiveness of radioiodine therapy in Graves' disease patients with and without goitres under conditions of mild iodine deficiency using several tissue-absorbed doses. The second aim was to detect further parameters which might be predictive for treatment outcome. Finally, we wished to determine the deviation of the therapeutically achieved dose from that intended. Activities of 185-2,220 MBq radioiodine were calculated by means of Marinelli's formula to deliver doses of 150, 200 or 300 Gy to the thyroids of 224 patients with Graves' disease and goitres up to 130 ml in volume. Control of hyperthyroidism, change in thyroid volume and thyrotropin-receptor antibodies were evaluated 15{+-}9 months after treatment for each dose. The results were further evaluated with respect to pre-treatment parameters which might be predictive for therapy outcome. Thyroidal radioiodine uptake was measured every day during therapy to determine the therapeutically achieved target dose and its coefficient of variation. There was a significant dose dependency in therapeutic outcome: frequency of hypothyroidism increased from 27.4% after 150 Gy to 67.7% after 300 Gy, while the frequency of persistent hyperthyroidism decreased from 27.4% after 150 Gy to 8.1% after 300 Gy. Patients who became hypothyroid had a maximum thyroid volume of 42 ml and received a target dose of 256{+-}80 Gy. The coefficient of variation for the achieved target dose ranged between 27.7% for 150 Gy and 17.8% for 300 Gy. When analysing further factors which might influence therapeutic outcome, only pre-treatment thyroid volume showed a significant relationship to the result of treatment. It is concluded that a target dose of 250 Gy is essential to achieve hypothyroidism within 1 year after radioiodine therapy in Graves' disease patients with goitres up to 40 ml in volume. Patients with larger goitres might need higher doses

  4. Thyroid nodule

    ... 2016:chap 14. Read More Chronic thyroiditis (Hashimoto disease) Laryngeal nerve damage Multiple endocrine neoplasia (MEN) II Thyroid cancer Thyroid cancer - medullary carcinoma Thyroid gland removal Patient Instructions Thyroid gland ...

  5. Evaluation of surface radiation dose to the thyroid gland and the gonads during routine full-mouth intraoral periapical and maxillary occlusal radiography

    Soheyl Sheikh

    2010-01-01

    Full Text Available Aim: The quantitative aspects of radiation doses to critical organs can help the dental professionals to take the necessary radiation protective measures as deemed necessary and can help the general public to allay radiation exposure fear in dental radiography, if any. Our study determines the surface radiation dose to thyroid and gonads in full-mouth intraoral periapical (IOPA and maxillary occlusal radiography.Materials and Methods: A total number of 120 subjects participated in the study. The surface radiation dose was estimated to the thyroid gland and the gonads in full-mouth IOPA radiography using 10 IOPA (E speed films and in maxillary occlusal radiography. The measurements were calculated using a digital pocket dosimeter (PD-4507.Results: The average dose at the thyroid gland level during full-mouth intraoral and maxillary occlusal radiography was estimated to be 10.93 mRads (1.093 Χ 10 -2 mGy and 0.4 mRads (4.0 Χ 10 -2 mGy, respectively. The average surface radiation dose at the gonadal region during a full mouth intraoral and maxillary occlusal radiography was estimated to be 1.5 mRads (1.5 Χ 10 -2 mGy and 0.15 mRads (1.5 Χ 10 -3 mGy, respectively. Conclusion: Our results suggest that although the radiation exposure doses to critical organs namely thyroid and gonads is within the safe limits still precautionary measures for these organs are advocated.

  6. Relationships between exposure dose and additional filter thickness in the X-ray diagnosis

    For the purpose of reduction of exposure dose in the X-ray diagnosis, authors examined the effect of additional filter thickness on the dose. The apparatus was Toshiba KXO-30F with filter thickness of 2.3 mm Al. For the additional filters, aluminium plates of 0.5 mm and 1.0 mm thickness were used. Dosimetry was done with VICTOREEN RADOCON 500 and with the ionization chambers VICTOREEN RADOCON 550-5 and 30-330, and X-ray analysis for measuring effective energy, with KYOKKO MODEL 100. Phantoms were polystyrene plates and manikin (Kyotokagakuhyohon PB-10). The incident surface dose and irradiation time were examined with varied phantom thickness. Further, the influence of the additional filter thickness was examined on the half-value thickness and effective energy of tube voltage. When the additional filter thickness was more than 10 mm Al, the incident surface dose was found hardly changed and irradiation time was 2 times as long. At 10.0 mm Al thickness, the thicker was the phantom, the smaller were the exposure dose and irradiation time. The thicker was the additional filter, the lower was the resolution of the site necessary to enhance the contrast, such as bone. Thus, the reduction of the dose requires the appropriate selection of the suitable tube voltage, additional filter thickness and sensitive film. (K.H.)

  7. Effective additional gamma dose for general population and workers from a Mexican radioactive waste site

    The environmental effective gamma-dose rate has been determined at the Mexican Storage Centre for Radioactive Waste (SCRW) and surrounding communities. Soil samples were analysed for 226Ra, 235U, 137Cs and 40K concentration activities. The outdoor effective gamma dose rate was higher at the SCRW where industrial radioactive sources and uranium ore piles were stored in the past. Some nearby locations, where the action of the rain on the piles promoted the transport and surface migration of 226Ra, 235U and 137Cs, also showed an increased gamma dose rate. The gamma dose rate at distant communities (local background) was evaluated with data obtained along 10 years measurements. The additional effective external dose for the general public at the 200 m neighbouring zone of the site, was two times higher than that from the local background. The outdoor average external effective dose for workers due to the SCRW operation was 20 times than for the local background

  8. Air sampling system for evaluating the thyroid dose commitment due to fission products released from reactor containment. Final report

    Accidental releases of radioactivity from fission reactors will consist of active vapors and aerosols. Composition of the released plume or cloud will depend on the energy of release and fission product volatility. In accidents at Windscale and SL-1, 131I was the predominant isotope present in both the initial cloud and later release. Thus an air sampling system was developed for efficient radioiodine collection. The air sampling, readout, and dose assessment system was developed to be used in the environment after loss of containment accidents. The system can detect less than 1 rem dose commitments to thyroids of 5 year old children for immersion times of 10 hours or less. The air mover can be operated on either 110V ac power or 12V dc power available from vehicles with cigar lighter sockets. An inorganic silver loaded silica gel adsorber was developed for high mehyl iodine, HOI, and elemental iodine efficiency and low noble gas efficiency. A peal away high efficiency particulate filter permits the gaseous and particulate sample fractions to be evaluated separately. Predicted particulate iodine is combined with the adsorbed component to account for the total radioiodine in a given sample

  9. High-dose radioiodine treatment for differentiated thyroid carcinoma is not associated with change in female fertility or any genetic risk to the offspring

    Background: We tried to evaluate the female fertility and genetic risk to the offspring from the exposure to high-dose 131I by assessing the pregnancy outcomes and health status of the children of female patients with differentiated thyroid cancer who had received therapeutic doses of 131I. Materials and Methods: From 1967 to 2002, a total of 1,282 women had been treated with 131I. Of these patients, 692 (54%) were in the reproductive age group (18-45 years). Forty women had a total of 50 pregnancies after high-dose 131I. Age at presentation ranged from 16 to 36 years (mean, 23 ± 4 years). Histopathology was papillary thyroid cancer in 32 cases and follicular thyroid cancer in 8 cases. Results: Single high-dose therapy was given in 30 cases, 2 doses were given in 7 cases, 3 doses were given in 2 cases, and four doses were given in 1 case in which lung metastases had occurred. In 37 patients (92%), disease was successfully ablated before pregnancy. Ovarian absorbed-radiation dose calculated by the MIRD method ranged from 3.5 to 60 cGy (mean, 12 ± 11 cGy). The interval between 131I therapy and pregnancy varied from 7 to 120 months (37.4 ± 28.2 months). Three spontaneous abortions occurred in 2 women. Forty-seven babies (20 females and 27 males) were born. Forty-four babies were healthy with normal birth weight and normal developmental milestones. Twenty women delivered their first baby after 131I therapy. The youngest child in our series is 11 months of age, and the oldest is 8.5 years of age. Conclusions: Female fertility is not affected by high-dose radioiodine treatment, and the therapy does not appear to be associated with any genetic risks to the offspring

  10. The effect of additional high dose carbon implantation on the tribological properties of titanium implanted steel

    The tribological properties and the structural changes of hardened steel implanted with titanium followed by carbon were investigated as a function of additional carbon dose. The dose of Ti was 5.1017 Ti cm-2 and the additional C doses were 0, 4.1017, 8.1017 and 1.2.1018 Ccm-2. After Ti implantation, the steel surface transformed to a Fe-Ti-C ternary amorphous phase. Additional implantation of carbon to a dose of 4.1017 Ccm-2 produced fine TiC precipitates dispersed in the ternary amorphous matrix. When the additional C dose exceeded 8.1017 Ccm-2, very fine graphite precipitates appeared in the ternary amorphous phase. The steel surface with very fine graphite precipitates exhibited superior tribological properties. The benefits provided by additional high dose carbon implantation are considered as follows: strengthening of the amorphous phase, thickening of the modified layer, dispersion strengthening of the implanted layer by very fine graphite precipitates and lubrication effect by graphite particles. Comparing the friction properties of Ti+C implanted steel with that of C implanted steel, the role of Ti implantation is to reduce the friction of the surface during sliding and the role of C implantation is to increase the lifetime of the surface against wear. (orig.)

  11. Lung Toxicity in Radioiodine Therapy of Thyroid Carcinoma: Development of a Dose-Rate Method and Dosimetric Implications of the 80-mCi Rule

    Sgouros, George; Song, Hong; Ladenson, Paul W.; Wahl, Richard L.

    2006-01-01

    Based on an extensive dataset analyzed by Benua et al., a whole-body retention threshold of 2.96 GBq (80 mCi) at 48 h has been used to limit the radioactivity of 131I administered to thyroid cancer patients with diffuse pulmonary metastases. In this work, the 80-mCi activity retention limit is used to derive lung-absorbed doses and dose rates. The resulting dose-rate–based limits make it possible to account for patient-specific differences in lung geometry. This is particularly important, for...

  12. Thyroid diseases after Chernobyl accident

    Radioactive iodine is released at every atomic-bomb testings and nuclear plants accidents and radioactive iodine is taken up by thyroid glands (internal radiation). In addition to the internal radiation, radioactive fallout causes the external radiation and thyroid glands are known to be sensitive to the external radiation. Furthermore, patients with radiation-induced thyroid disease can survive for a long time regardless of the treatment. The survey of thyroid diseases, therefore, is very sensitive and reliable ways to investigate the effects of radiation caused by atomic bomb explosion, testing and various types of nuclear plants' accidents. Our group from Nagasaki University was asked to investigate the thyroid diseases and jointed to the Sasakawa Project. In order to investigate the effects of radiation on thyroid disease, it is essential 1) to make a correct diagnosis in each subject, 2) to calculate a correct radiation dose in each subject and finally, 3) to find out the correlation between the radiation dose and thyroid diseases including age-, sex- and area-matched controls. We have established 5 centers (1 in Russia, 2 in Belarus, 2 in Ukraine) and supplied the most valuable ultrasonography instruments, commercial kits for the determination of serum free T4 and TSH level and for the autoantibodies, instrument for urinary iodine measurements, syringers, tubes, refrigerators, etc. We visit each center often and asked people at centers to come to Japan for training. Protocol of investigation is essentially the same as that in Nagasaki, and we are planning to investigate more than 50,000 children within 5 years. We are hoping to show a definite conclusion in the near future. Recent articles are also discussed. (author)

  13. Effects of a Single Venous Dose of Zinc on Thyroid Status in Healthy Individuals and Patients With Graves' Disease

    Farooqi, Lubna; Gláucia M. F. S. Mazeto; Shuhama, Tadao; Brandão-Neto, José

    2000-01-01

    Zinc metabolism may regulate thyroid function acting at TRH (thyrotropin-releasing hormone) synthesis, peripheral deiodination of T4 (tetraiodothyronine), and binding of thyroid hormones to nuclear receptors. The aim of this study was to investigate the effect of acute zinc administration on TSH (thyroid-stimulating hormone), FT3 (free triiodothyronine), and FT4 (free tetraiodothyronine) in 10 healthy individuals and 12 hyperthyroid patients with Graves' disease. All these individuals were st...

  14. Proposal for dose measurement in the crystalline lens and thyroid in computerized tomography of paranasal sinuses; Proposta de medicao de dose no cristalino e na tireoide em exame de tomografia de seios da face

    Mello, Ana Caroline; Machado Neto, Vicente, E-mail: ana.caroline91@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR/PPGEB), Curitiba, PR (Brazil). Programa de Pos Graduacao em Engenharia Biomedica

    2014-07-01

    With the evolution of diagnostic imaging equipment, a computerized tomography (CT) has become one of the most used tests to assess pathologies affecting the paranasal sinuses. This work aims at presenting a method of obtaining measurements of dose in the eye lenses and thyroid, from the execution of CT of the paranasal sinuses protocol. Experimental procedure will be used in an object simulator (phantom) head and neck made with accessible materials and thermoluminescent dosimeters (TLDs) of LiF: Mg,Ti for the absorbed dose in the regions of interest, when exposed to radiation in a CT scanner 16 channels. After the dosimetric evaluation with phantom use, this methodology will be applied in vivo, or in patients with medical request for the examination and approval by the Ethics Committee. Thus, at the end of this survey protocols and actions aimed at reducing the absorbed dose in the eye lenses and thyroid without impairing the diagnostic image quality can be proposed. (author)

  15. Predictive estimate of effective dose to family members from patients of thyroid carcinoma treated with radioiodine

    The radiation dose received by any member of the family attending to the patient released after 131I therapy, primarily will be influenced by the whole body activity retained by the patient, the effective half-life of 131I in the body and the length and proximity of contact with the patient i e. the occupancy factor. According to International Commission of Radiological Protection (ICRP 60), the annual effective dose limit for the members of the public is 1 mSv. In the reports available of the doses received by the family members from patients treated with 131I, the doses either have been estimated using dosimeters worn by the relatives for a specific time period or have been theoretically calculated considering physical decay of the radionuclide. In the present study, the likely doses to the family members were estimated based on calculations, wherein the actual effective half-life of 131I and whole body activity of 131I have been used. Two distances (0.6 m and 1 m) and 4 different occupancy factors (0.125, 0.25, 0.75 and 1), were considered for these calculations. In India, the patient is released from the hospital when the whole body 131I activity is less than or equal to 555 MBq (15 mCi), a limit stipulated by AERB. The objective of retaining the patient in the hospital till the whole body retained activity has fallen below the recommended limit is to minimize the radiation exposure to the general public and family members. Our predictive estimated values of effective dose suggests that with proper instructions of radiation safety and hygiene to the patient, doses to the family members and public can be kept below the limit of 1 mSv. Since some individuals in the family will be knowingly and willingly involved in the care, support and comfort of the patient, a dose of more than 1 mSv is acceptable, however, it should be constrained so that it does not exceed 5 mSv. (author)

  16. Effect on thyroid function and serum PTH, BGP, CT of small dose of iodine 131 combined with Methimazole in patients with hyperthyroidism

    Jia-Yin Qiu; Yan Zhu; Qing-Hong Xi

    2016-01-01

    Objective:To observe the effect Effect on thyroid function and serum PTH, BGP, CT of small dose of iodine 131 combined with Methimazole in patients with hyperthyroidism. Methods:A total of 104 patients with hyperthyroidism willing be incorporated into the study were randomly divided into the observation group (54 cases) and the control group (50 cases). The control group was treated with Methimazole, and the observation group was given a small dose of iodine 131 the basised on the control group. For 2 months, to observe the changes of thyroid function (TT3, TT4, FT3, FT4 and TSH) and bone metabolism related indexes (PTH, BGP and CT) of the two groups. Results:(1) After treatment, TT3, FT3, TT4 and FT4 of the two groups decreased with before, and the observation group improved more significantly than the control group, with statistical difference;TSH of the two groups had no significant change. (2) After treatment, BGP and CT of the two groups decreased and PTH increased, the observation group improved more significantly than the control group, with statistical difference. Conclusion:small dose of iodine 131 combined with Methimazole can correct thyroid function and bone metabolism quickly in patients with hyperthyroidism.

  17. Behavior and awareness of thyroid cancer patients in Korea having non-hospitalized low-dose radioiodine treatment with regard to radiation safety

    With the recent increase in incidence of thyroid cancer, non-hospitalized low-dose (NH-LD) radioiodine treatment (RIT) has also increased rapidly. The radioactivity limit that is allowed to be administered without hospitalization depends on individual calculation, based partly on patients' behavior. In this study, Korean patients' behavior in relation to radiation safety in NHLD RIT was surveyed. A total of 218 patients who underwent NH-LD RIT of 1.1 GBq 131I in a single center were surveyed. The patients underwent RIT with a standard protocol and the survey was performed by interview when they visited subsequently for a whole-body scan. The survey questionnaire included three parts of questions: general information, behavior relating to isolation during RIT, and awareness of radiation safety. After administration of radioiodine, 40% of patients who returned home used mass transportation, and another 47% went home by taxi or in car driven by another person. Isolation at home was generally sufficient. However, 7% of patients did not stay in a separate room. Among the 218 patients, 34% did not go home and chose self-isolation away from home, mostly due to concerns about radiation safety of family members. However, the places were mostly public places, including hotels, resorts, and hospitals. About half of the patients replied that access to radiation safety information was not easy and their awareness of radiation safety was not satisfactory. As a result, 45% of patients wanted hospitalized RIT. In many countries, including Korea, RIT is continuously increasing. Considering the radiation safety of patients' family members or the public and the convenience of patients, the pretreatment education of patients should be enhanced. In addition, the hospitalization of patients having low-dose therapy is recommended to be seriously considered and expanded, with the expansion of dedicated treatment facilities

  18. Thyroid Nodules

    ... Your Body in Balance › Thyroid Nodules Fact Sheet Thyroid Nodules March 2010 Download PDFs English Espanol Hindi ... Singer, MD Leonard Wartofsky, MD What is the thyroid gland? The thyroid gland is a butterfly-shaped ...

  19. Dose reduction in thorax radiography in simulated neonates with additional filtration and digital luminescence radiography

    Purpose: To determine the minimum acceptable radiation dose for an adequate image quality in thorax a.p. radiographs of neonates using mobile X-ray equipment. Material and Methods: The influence of additional filtration (1.0 mm Al+0.1 mm Cu) on image quality and radiation dose was determined for the speed class 400 screen-film system (SFS) and digital luminescence radiography (DLR) by making radiographs of a test phantom. Conventional and digital thorax a.p. radiographs of a rabbit were produced using various tube current-time products. The quality of the rabbit radiographs was judged by eight radiologists applying image quality criteria according to the German guidelines and the recommendations of the European Community. Results: The added filter resulted in a dose reduction of 39% at 66 kV. DLR gave a further dose reduction of 25% in comparison to the speed class 400 SFS while maintaining adequate image quality, i.e. the radiographs were clinically acceptable with regard to quality criteria. Conclusion: The radiation dose resulting from thorax a.p. radiographs of neonates can be reduced by approximately 50% with the use of additional filtration and DLR. (orig.)

  20. Reconstruction of dose loads on population in the initial period of the Chernobyl accident and estimation of thyroid cancer risk in Belarus

    The Chernobyl accident caused significant long-term consequences to the environment, public health, and economic status of Belarus. The contamination from short-lived radionuclides, in particular iodine 131, was so high that the subsequent exposure of millions of people has been termed 'iodine shock'. During the first days of the accident, the majority of the dose of radiation received by the residents of Belarus was to the thyroid gland. This will affect the health of the population for a long time to come. The resulting epidemic of childhood thyroid cancer is the first indisputable health after-effect of the Chernobyl accident. Thyroid cancer morbidity among children increased more than 10 fold in the post-Chernobyl period. Maps of cesium 137, which has a half life of 37 years, have been published, but it is evident, that the distribution of thyroid cancer morbidity differs from the known distribution of cesium 137 in soil. Territorial distribution of thyroid cancer morbidity is often compared to distribution of cesium 137 in the soil. This practice is inaccurate but often utilized since no maps of iodine 131 contamination exist, due to its short half life of 8.04 days. Reconstruction of the spatial distribution of short-lived isotopes in the first days after the accident, could clarify the impact of radiation on human health and allow for a spatial and temporal prognosis of the development of the cancer epidemic, particularly, thyroid cancer. Due to the unfortunate fact that the measuring equipment was inadequate to properly monitor the scale of radiation exposure during the early period of the accident, detailed direct information on the deposition of the short-lived radionuclides and the doses to the population has been irretrievably lost. Now the only way to reconstruct the dynamics of the radioecological situation of the initial period of the Chernobyl accident is to make a retrospective assessment of radiation exposures related to the short

  1. Evidence of C-cell destruction in the thyroid gland of mice exposed to high 131I doses

    The parafollicular cells of the thyroid gland were visualized by means of the Sevier-Munger silver technique in normal mice and in mice receiving 131I in amounts sufficient to completely destroy the thyroid tissue. The destruction of the C-cells was observed in all 131I injected mice, and no histologic signs of recovery were seen during a period of 40 days following the treatment. (orig.)

  2. Additional diagnostic value of low dose CT in ventilation/perfusion hybrid SPECT for pulmonary embolism

    Objective: To evaluate the assistant diagnostic value of low dose CT in patients with pulmonary embolism (PE) based on ventilation/perfusion (V/Q) SPECT imaging. Methods: One hundred and two patients with clinical suspected PE had been enrolled for this retrospective study. The final diagnosis of PE was made according to the 2008 guidelines of European Society of Cardiology (ESC). All patients underwent V/Q SPECT/CT (Hawkeye 4, GE). The imaging findings from low dose CT lung window were used for differential diagnoses of abnormal regions in SPECT imaging. The diagnostic efficiency of V/Q SPECT alone was compared with that of V/Q SPECT combined with low dose CT scan. Crosstabs χ2 test was performed using SPSS 13.0 software. Results: Twenty-nine patients (28.43%, 29/102) were finally diagnosed as PE. V/Q SPECT alone had a sensitivity of 93.10% (27/29), a specificity of 90.41% (66/73), and an accuracy of 91.18% (93/102). With additional diagnostic information from low dose CT, the diagnostic specificity increased to 95.89% (70/73, χ2=1.72, P>0.05), and the accuracy increased to 95.10% (97/102, χ2=1.23, P>0.05) though the sensitivity remained the same. Conclusion: Imaging information from low dose CT in hybrid SPECT/CT may enhance V/Q diagnostic accuracy for PE. (authors)

  3. Research on additional external exposure dose rate measurement by in-situ HPGe γ spectrometer

    A spectrometric method for additional exposure dose rate (external dose rate due to γ-ray emitted by artificial nuclides) measurement is introduced. The principle of this method is that: strip off the spectrum attributed to the natural radionuclides from the gamma spectrum collected by in situ HPGe spectrometer, and get the spectrum attributed to the artificial radionuclides, then integrate the stripped spectrum with corresponding spectrum-dose conversion function (G(E) function) values to acquire additional exposure dose rate. Standard spectrums attributed to nuclides in U series, Th series and 40K were calibrated by in situ HPGe spectrometer at airborne pads, and the interference caused by other nuclides was eliminated by the inverse matrix calculations. The natural compositions in the spectrum is stripped according to the standard spectrums. Six standard γ-ray sources were used to acquire the response functions of the HPGe spectrometer, then the G(E) function was calculated by the least square method. Finally, the utility of this method was verified by in situ experiment, and the factors that influence the precision of the results are discussed. (author)

  4. Radioprotection of salivary glands by amifostine in high-dose radioiodine treatment. Results of a double-blinded, placebo-controlled study in patients with differentiated thyroid cancer

    Background and purpose: Parenchymal impairment of salivary glands following high-dose radioiodine treatment is a well-known side effect in general caused by free radicals. Therefore, the radioprotective effect of the radical scavenger amifostine was evaluated prospectively in patients receiving high-dose radioiodine treatment. Patients and methods: Parenchymal function was assessed by quantitative salivary gland scintigraphy performed in 50 patients with differentiated thyroid cancer prior to and 3 months after high-dose radioiodine treatment with either 3 GBq 131I (n=21) or 6 BGq 131I (n=29) in a double-blinded, placebo-controlled study. Twenty-five patients treated with 500 mg/m2 amifostine intravenously prior to high-dose radioiodine treatment were compared to 25 control patients receiving physiological saline solution. Xerostomia was graded according to WHO-criteria. Results: In 25 control patients high-dose radioiodine treatment significantly (p<0.001) reduced parenchymal function of parotid and submandibular glands by 40.2±14.1% and 39.9±15.3%, respectively. Nine out of these 25 patients developed Grade I and 2 Grade II xerostomia. In contrast, in 25 amifostine-treated patients there was no significant (p=0.691) decrease in parenchymal function following high-dose radioiodine treatment, and xerostomia did not occur in any of them. Conclusion: Parenchymal damage of salivary glands induced by high-dose radioiodine treatment can be significantly reduced by amifostine which may improve quality of life of patients with differentiated thyroid cancer. (orig.)

  5. "The Dose Makes the Poison": Informing Consumers About the Scientific Risk Assessment of Food Additives.

    Bearth, Angela; Cousin, Marie-Eve; Siegrist, Michael

    2016-01-01

    Intensive risk assessment is required before the approval of food additives. During this process, based on the toxicological principle of "the dose makes the poison,ˮ maximum usage doses are assessed. However, most consumers are not aware of these efforts to ensure the safety of food additives and are therefore sceptical, even though food additives bring certain benefits to consumers. This study investigated the effect of a short video, which explains the scientific risk assessment and regulation of food additives, on consumers' perceptions and acceptance of food additives. The primary goal of this study was to inform consumers and enable them to construct their own risk-benefit assessment and make informed decisions about food additives. The secondary goal was to investigate whether people have different perceptions of food additives of artificial (i.e., aspartame) or natural origin (i.e., steviolglycoside). To attain these research goals, an online experiment was conducted on 185 Swiss consumers. Participants were randomly assigned to either the experimental group, which was shown a video about the scientific risk assessment of food additives, or the control group, which was shown a video about a topic irrelevant to the study. After watching the video, the respondents knew significantly more, expressed more positive thoughts and feelings, had less risk perception, and more acceptance than prior to watching the video. Thus, it appears that informing consumers about complex food safety topics, such as the scientific risk assessment of food additives, is possible, and using a carefully developed information video is a successful strategy for informing consumers. PMID:25951078

  6. Association of Papillary Thyroid Carcinoma and Graves' Disease. Unexpected Development and Efficiency of Ablative Dose with Recombinant Human Thyrotropin (rhTSH)

    middle and lower cervical region right and left lower neck. He was reoperated on 4 months after his initial S: Resection of epithelial proliferation with thyroid aspect in superior mediastinum region. Pathology: Node with extensive infiltration of neoplastic proliferation of follicular variant of papillary carcinoma with areas of connective tissue infiltrated periganglionar of papillary thyroid cancer. Lab 40 days after the second surgery: TSH 2.3 μIU/mL, FT4 0.82 ng/dL, Tg 4.7 ng/mL. Neck and chest CT showed neither pathological lesions nor lymphadenopathy. I131 uptake with 7.4 MBq was: 1st hour: 8 % and 24 hours: 12 %. Neck Scan: Multiple areas of tracer fixation in the neck. No pathological signs on neck palpation. Ablative dose of 7.4 GBq of I131 was performed to the patient, previously using rhTSH (two doses of 0.9 mg), reaching TSH >100 μIU/mL. Scan post ablative dose: Important focus on right paratracheal region. Neck MRI showed: Absence of thyroid gland. Rounded image of about 10 mm at right paratracheal level. The patient initiates suppressive therapy with levothyroxine (LT4). Six months after ablation therapy (without LT4): TSH >100 μIU/mL, Tg: 13.8 ng/mL, TGA: 431 IU/mL. Body Scan with 2 mCi: Pathological focus of radioiodine behind the right sternoclavicular joint. New neck MRI: Image in right pretracheal region smaller than the previous study. The patient received 5.55 GBq of I131. The same radioiodine treatment was repeated 8 months later. At present, 4 years after the patient's initial surgery, he is in good general health, performing his normal activities, with TGA in sharp decline, negative I131body scan and without signs of persistent or recurrent disease. Conclusions: We report a case of follicular variant papillary TC associated with GD with concomitant development of hyperthyroidism, with positive TGA, in a 22-year-old obese man. Highlights: 1) The importance of initial US exploration in a patient with GD, 2) Residual neoplastic lymph node

  7. Effects of potassium iodide (KI) protective dose on the course of thyroid diseases diagnosed at the Outpatient Endocrinologic Clinic in Lodz, 1986, before Chernobyl accident

    2521 patients of the Lodz Outpatient Endocrinologic Clinic (2290 females, 231 males; inhabitants of the central region of Poland were included in the study. The obtained results indicate that: 1) KI administration neither increased the number of exacerbations of hyperthyroidism nor affected the onset of new cases of that disease in 1986. 2) The same can be said about the cases of thyroiditis and hypothyroidism. 3) No increase of ATMA or ATG antibodies ''prevalence, as well as no elevation of those antibodies'' titres after KI prophylactic dose were observed in the patients with Grave's disease and chronic thyroiditis, when compared to persons who did not take Lugol's iodine. 4) The course of the majority of diseases diagnosed in 1986, evaluated with use of the, so called, test for analysis of trends, became unchanged. 5) There were adverse side effects noted after KI in 32 patients out of all the examined 774 patients (i.e., in 4.13%); five of the affected patients required medical care. 6) After iodine tincture; side effects occurred in three patients in the group of 35 patients included in the examination, i.e., in 8.57%; none of the affected patients required medical care. 7) Our results, comprising the four year observation period after Chernobyl accident, do not indicate any increased incidence of malignant neoplasms of the thyroid gland, what confirms the apparent theoretical data; much longer observation time is necessary to reveal phenomena of scholastic type (10-15 years). (author). 30 refs, 11 figs, 14 tabs

  8. Normalization of lymphocyte count after high ablative dose of I-131 in a patient with chronic lymphoid leukemia and secondary papillary carcinoma of the thyroid: case report

    The authors report the case of a 70-year-old male patient with chronic lymphoid leukemia who presented subsequently a papillary carcinoma of the thyroid with metastases to regional lymph nodes. The patient was treated with surgical thyroidectomy with regional and cervical lymph node excision and radioiodine therapy (I-131). The protocolar control scintigraphy 4 days after the radioactive dose showed I-131 uptake in both axillae and even in the inguinal regions. PET/CT showed faint FDG-F-18 uptake in one lymph node of the left axilla. An ultrasound guided fine needle biopsy of this lymph node identified by I-131 SPECT/CT and FDG-F-18 PET/CT revealed lymphoma cells and was negative for thyroid tissue and thyroglobulin content. The sequential blood counts done routinely after radiation treatment showed a marked fall until return to normal values of leucocytes and lymphocytes (absolute and relative), which were still normal in the last control 19 months after the radioiodine administration. Chest computed tomography showed a decrease in size of axillary and paraaortic lymph nodes. By immunohistochemistry, cells of the lymphoid B lineage decreased from 52% before radioiodine therapy to 5% after the procedure. The authors speculate about a possible sodium iodide symporter expression by the cells of this lymphoma, similar to some other non-thyroid tumors, such as breast cancer cells. (author)

  9. Collection and use of individual behavioral and consumption rate data to improve reconstruction of thyroid doses from nuclear weapons tests in Kazakhstan

    Full text: Historical behavioral and consumption rate data were collected from residents of Kazakhstan exposed to nuclear weapons testing fallout using a focus group data collection strategy. These data will enable improved thyroid dose estimation in a radiation epidemiological study being carried out the U.S. National Cancer Institute. The study on the relationship of radiation exposure from weapons testing fallout and thyroid disease in a cohort of 2,994 subjects is now in a stage of improving earlier dose estimates based on individual information collected from a basic questionnaire administered to the study population in 1998. The study subjects of both Kazakh and Russian origin were exposed during childhood to radioactive fallout from nuclear weapons tests conducted at the Semipalatinsk Nuclear Test Site between 1949 and 1962. Due to the long time since exposure, a well developed strategy is necessary to encourage accurate memory recall. Limitations of the data collected in 1998 suggested the need to obtain reliable information that is tailored specific to the requirements of the dose reconstruction algorithm and to the evaluation of individual dose uncertainties. Focus group data collection in Kazakhstan in 2007 involved four 8-person focus groups (three of women and one of men) in each of four exposed settlements where thyroid disease screening was conducted in 1998. Age-specific data on relevant childhood behaviour, including time spent indoors and consumption of milk and other dairy products from cows, goats, horses, and sheep, were collected from women's groups. Men's focus groups were interviewed about construction materials of houses and schools as well as animal grazing patterns and supplemental feed to animals. Information obtained from the focus groups are being used to derive the settlement-, ethnicity-, age-, and gender-specific (where appropriate) probability density distributions on individual consumption rates of milk and dairy products

  10. Randomized prospective study comparing a single radioiodine dose and a single laser therapy session in autonomously functioning thyroid nodules

    Døssing, Helle; Bennedbaek, Finn Noe; Bonnema, Steen Joop;

    2007-01-01

    OBJECTIVE: To compare the efficacy of interstitial laser photocoagulation (ILP) with radioiodine in hot thyroid nodules. DESIGN: Thirty consecutive outpatients with subclinical or mild hyperthyroidism and a scintigraphically solitary hot nodule with extraglandular suppression were randomized to...... effects were seen. CONCLUSIONS: This first randomized study, comparing ILP with standard therapy, demonstrates that ILP and (131)I therapy approximately halves thyroid nodule volume within 6 months; but in contrast to (131)I, extranodular thyroid volume is unaffected by ILP and no patient developed...... hypothyroidism. Using the present design, ILP seems inferior to (131)I therapy in normalization of serum TSH. The potential value of ILP as a non-surgical alternative to (131)I needs further investigation...

  11. Issues related to radioactive iodine ablation in patients with differentiated thyroid carcinoma undergoing thyroid surgery

    Differentiated thyroid carcinoma (DTC) is the most common malignant tumor of thyroid gland, including papillary thyroid carcinoma, follicular thyroid carcinoma and the mixed type. Treatment methods include surgery, radioactive iodine treatment and endocrine treatment, in which radioactive iodine treatment for thyroid carcinoma is an important part of the treatment or procedure. With the ongoing research and exploration of radiation treatment, the recombinant human thyroid stimulating hormone assisted in radioactive iodine ablation of thyroid remnants, radioactive iodine to remove a lot of residual thyroid tissue, the radioactive iodine dose selection and other aspects of knowledge and practice are constantly updated. This paper summarizes recent progess in the radioactive iodine ablation. (authors)

  12. Q12 differentiated thyroid cancer (DTC). Stimulation of the endogenous TSH with multiples doses of TRH and its treatment with 131I. Three experience years

    The search of an alternative method to the rh-TSH to stimulate endogenous rising of TSH previous to thyroid ablation with 131I in patients with CDT operated. The purpose of the work began in 2001 in Paraguay using multiple dose of TRH IV (200μU of TRH Threlea Argentina) to stimulate the own TSH of patients previous to 131I ablation. It is known that the injection of an unique dose of 200μU of TRH IV achieves the increasing of the endogenous TSH in patients with differentiated thyroid carcinoma up to 30 - 35 mUI/L at the end of the first hour, however, there is not statistical data of the effects of multiple injections of TRH applied IV or IM in operated patients of DTC previous to the ablation with 131I. Since 2001-2007, two hundred patients operated for DTC were studied by this method, 120 were papillary cancer and 80 follicular cancer. One hundred eighty did not have distance metastasis and 20 presented metastasis in thorax, pelvis and dorsal spine. Total thyroidectomy was carried out in 120 and total lobectomy with itsmectomy plus hemilobectomy of the other lobe in 80. All were treated with ablative dose of 100 mCi (3.700 mBq) of 131I, except those with metastasis which receive 150 mCi (5.500 mBq) with the previous stimulation with TRH IV with two daily dose for three days with previous suspension of L-tiroxine for 25 days and replaced by triyodotiroxine 25 mcg/d for 15 days with suspension 10 days before the stimulation with TRH and treatment with 131I. Two patients with metastasis received another extra dose of 150 mCi (5.550 MBq) 6 months later. One presented uptake in thyroid bed one year after the ablation received a new ablative dose of 100 mCi (3.700 mBq) of 131I. All the patients were interned and isolated by 48 hours. Twenty feminine patients had later pregnancies in 1-3 years after their ablative dose with healthy products. TSH was measured during the stimulation with TRH in all patients. Whole body scan was done with a gamma camera Spect LFOV

  13. Changes of radiation dose and image quality due to additional filtration material in computed radiography

    Filter absorbs low-energy X-ray to increase the average energy and reduces patient exposure dose. This study investigates if the materials of Mo and W could be used for the digital imaging device CR by conducting image assessment and dose measurement of SNR, FOM and histogram. In addition, measurement of beam quality was conducted depending on the material of the filter, and at the same time, a proper combination of filters was examined depending on the change in tube voltage (kVp). In regard to entrance skin dose, Mo filter showed the dose reduction by 42∼56%, compared to Cu filter. Moreover, Mo filter showed higher transmission dose by around 1.5 times than that of Cu filter. In image assessment, it was found that W was unsuitable to be used as a filter, whereas Mo could be used as a filter to reduce dose without decline in image quality at the tube voltage of 80 kVp or higher. As tube voltage increased, 2.0 mm Al+0.1 mm Mo almost had a similar histogram width to that of 2.0 mm Al+0.2 mm Cu. Therefore, Mo filter can be used at relatively high tube voltage of 80 kVp, 100 kVp and 120 kVp. The SNR of 2.0 mm Al+0.1 mm Mo did not show any significant difference from those of 2.0 mm Al+0.2 mm Cu and 2.0 mm Al+0.1 mm Cu. As a result, if Mo filter is used to replace Cu filter in general radiography, where 80 kVp or higher is used for digital radiation image, patient exposure dose can be reduced significantly without decline in image quality, compared to Cu filter. Therefore, it is believed that Mo filter can be applied to chest X-ray and high tube voltage X-ray in actual clinical practice

  14. Effect of developmental low dose PBDE 47 exposure on thyroid hormone status and serum concentrations of FSH and inhibin B in male rats

    Andrade, A.J.M.; Kuriyama, S.N.; Akkoc, Z.; Talsness, C.E.; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin

    2004-09-15

    Several persistent halogenated organic compounds such as PCBs, dioxins and more recently, polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone homeostasis in experimental animals. Particular concern exists regarding exposure to these compounds during critical periods of development when thyroid hormones orchestrate the growth and differentiation of many organs including the brain and the testis. While the contamination levels of PCBs and other persistent organic pollutants have declined in the past years, increasing levels of PBDEs have been detected in environmental and human samples including human breast milk. PBDEs are produced in large quantities and used worldwide as flame retardants in electrical appliances, carpets and furniture upholstery. Similar to other halogenated environmental organic pollutants, PBDEs seem to present a wide range of toxic effects including reproductive, endocrine, neurobehavioral and hepatic toxicity. Recently, it has been demonstrated that in utero and pubertal exposures to DE-71 (a commercial mixture containing mostly tetra- and penta-bromodiphenyl ethers) significantly reduce thyroxine levels (T4) in rats. The present study has focused on the possible effects of the tetra- BDE congener 2,2'4,4'-tetrabromo diphenyl ether (PBDE 47) on thyroid hormone status and associated changes on FSH and inhibin B levels in the developing male rat. We administered a single dose to gravid dams on gestation day 6 of either 140 {mu}g/kg BW or 700 {mu}g/kg BW PBDE 47. These doses are pertinent to human exposure situation because a study by She et al.3 found a mean level of 33.3 {mu}g PBDE 47 /kg fat in human breast adipose tissue with a range from 7.01 to 196 {mu}g PBDE 47 /kg fat.

  15. Thyroid ultrasound

    ... that may or may not be cancerous (a tumor ). Sometimes the thyroid is enlarged without any nodules. ... to: Cysts Enlargement of the thyroid gland ( goiter ) Thyroid nodules Your doctor can use these ...

  16. Thyroid Surgery

    ... The American Thyroid Association Guidelines Task Force on Medullary Thyroid Carcinoma (2015) Radiation Safety in the Treatment of Patients with Thyroid Diseases by Radioiodine 131 I: Practice Recommendations of the ...

  17. Thyroid Problems

    ... producing a hormone knows as thyroid-stimulating hormone (TSH). Most people who have an underactive thyroid gland ... levels of T4 and high blood levels of TSH. Hyperthyroidism Also known as overactive thyroid and thyrotoxicosis, ...

  18. Thyroid Antibodies

    ... be limited. Home Visit Global Sites Search Help? Thyroid Antibodies Share this page: Was this page helpful? Also known as: Thyroid Autoantibodies; Antithyroid Antibodies; Antimicrosomal Antibody; Thyroid Microsomal Antibody; ...

  19. Reducing the shrinkage and setting dose in polyester resins by addition of metal oxides

    To an unsaturated polyester resin, metal oxides (MgO, CaO, BaO) were introduced which reacted with it for 200 h. In this modified resin cured by radiation, considerable reduction of setting dose as well as of the shrinkage of resin were observed in comparison with the unmodified resin. It has been also found that there is an addition of this effect with the previously observed antishrinking action of epoxy resin containing unsaturated bonds. The service properties of the resin modified with metal oxides have not changed, while its thermal stability has increased. (author)

  20. Additional benefit of higher dose green tea in lowering postprandial blood glucose

    Rita Lahirin

    2015-07-01

    Full Text Available Background: Green tea contains catechins that have inhibitory effects on amylase, sucrase, and sodium-dependent glucose transporter (SGLT which result in lowering of postprandial blood glucose (PBG. This beneficial effect has been widely demonstrated using the usual dose (UD of green tea preparation. Our study was aimed to explore futher lowering of PBG using high dose (HD of green tea in healthy adolescents.Methods: 24 subjects received 100 mL infusion of either 0.67 or 3.33 grams of green tea with test meal. Fasting, PBG at 30, 60, 120 minutes were measured. Subjects were cross-overed after wash out. PBG and its incremental area under the curve (IAUC difference between groups were analyzed with paired T-test. Cathecin contents of tea were measured using high-performance liquid chromatography (HPLC.Results: The PBG of HD group was lower compared to UD (at 60 minutes =113.70 ± 13.20 vs 124.16 ± 8.17 mg/dL, p = 0.005; at 120 minutes = 88.95 ± 6.13 vs 105.25 ± 13.85 mg/dL, p < 0.001. The IAUC of HD was also found to be lower compared to UD (2055.0 vs 3411.9 min.mg/dL, p < 0.001.Conclusion: Additional benefit of lowering PBG can be achieved by using higher dose of green tea. This study recommends preparing higher dose of green tea drinks for better control of PBG.

  1. Thyroid exposure in Ukrainian and White Russian children following the Chernobyl disaster and the resultant risk of acquiring thyroid cancer

    After a presentation of the main strong and weak points of various studies on the risk of acquiring thyroid cancer after the Chernobyl disaster this study summarises the results of a recent ecological study. 175,800 measurements of 131I activity in the human thyroid gland performed in the contaminated regions of the Ukraine and White Russia during the first weeks after the Chernobyl disaster served as a starting point for this study on thyroid exposure in Ukrainian and White Russian children following the Chernobyl disaster and the resultant risk of acquiring thyroid cancer. More than 10 measurements were performed in each of altogether 1,114 locations. Age and sex-specific doses were calculated for each of these locations within the 1968-85 birth cohort. 95% of all dose values were within the range of 0.017 to 0.69 Gy. Since 1990 the incidence of thyroid cancer within the study area has increased at a markedly higher rate than one would expect on the basis of the cohort members' growing age. In the period from 1990 to 2001 1,091 cases of surgery for thyroid cancer were reported. The additional absolute risk per 104 PY Gy was calculated as 2.5 (95% CI: 2.3;2.9). The additional relative risk per dose was calculated as 10 (95% CI: 8;12) Gy-1. These results are consistent with risk values found for thyroid cancer after external exposure during childhood. Assuming that the calculated risk values also apply for the intervention level of 0.05 Gy at which iodine tablets are distributed in the event of a major release of radioiodide this means that within the period of 4 to 15 years following the exposure 3 additional cases of thyroid cancer are expected to occur within a collective of 20,000 children and adolescents. This is equivalent to a 50% increase in the spontaneous incidence of the disease

  2. Correlation study of effect of additional filter on radiation dose and image quality in digital mammography

    Objective: To explore the effect of different additional filters on radiation dose and image quality in digital mammography. Methods: Hologic company's Selenia digital mammography machine and the post-processing workstations and 5 M high resolution medical monitor were used in this study. Mammography phantoms with the thickness from 1.6 cm to 8.6 cm were used to simulate human breast tissue. The same exposure conditions, pressure, compression thickness, the anode were employed with the additional filters of Mo and Rh under the automatic and manual exposure mode. The image kV, mAs, pressure, filter, average glandular dose (AGD), entrance surface dose (ESD), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image score according to ACR criteria were recorded for the two additional filters. Paired sample t test was performed to compare the indices of Mo and Rh groups by using SPSS 17.0. Results: AGD and ESD of Rh and Mo group were both higher with the increase of the thickness of all the phantoms. AGD, ESD and their increased value of Rh filter(1.484 ± 1.041, 7.969 ± 7.633, 0.423 ± 0.190 and 3.057 ± 2.139) were lower than those of Mo filter (1.915 ± 1.301, 12.516 ± 11.632, 0.539 ±0.246 and 4.731 ± 3.294), in all the phantoms with different thickness (t values were 4.614, 3.209, 3.396 and 3.605, P<0.05). SNR, CNR, and image score of Rh and Mo group both decreased with the increase of the thickness of all the phantoms. There were no statistical difference (P>0.05). Conclusions: Compared with Mo filter, Rh filter could reduce the radiation dose, and this advantage is more obvious in the thicker phantom when the same image quality is required. (authors)

  3. Anaplastic Thyroid Cancer: The Addition of Systemic Chemotherapy to Radiotherapy Led to an Observed Improvement in Survival—A Single Centre Experience and Review of the Literature

    Lowe, Natalie M.; Loughran, Sean; Slevin, Nicholas J.; Yap, Beng K.

    2014-01-01

    Introduction. Anaplastic thyroid carcinoma (ATC) is rare yet accounts for up to 50% of all thyroid cancer deaths. This study reviews outcomes of patients with confirmed ATC referred to a tertiary oncology centre plus reviews the literature to explore how poor outcomes may be improved. Materials and Methods. The management and outcomes of 20 patients with ATC were reviewed. Results. Median age at diagnosis was 69.5 years. 19 patients died due to ATC, 40% of whom died from asphyxiation. Median survival for all cases was 59 days. Patients who had previous surgery prior to other treatment modalities had a longer median survival overall compared to those who had not had previous surgery (142 days compared to 59 days) and produced the one long-term survivor. Chemotherapy followed by radiotherapy (without previous surgery) was associated with longer median survival (220 days). Palliative radiotherapy alone did not decrease the rate of death by asphyxiation when compared to other single modality treatments. Conclusion. Multimodality treatment including surgery when feasible remains the best strategy to improve survival and prevent death from asphyxiation in the management of ATC. The addition of chemotherapy to our institutional protocol led to improved survival but prognosis remains very poor. PMID:25184150

  4. Anaplastic Thyroid Cancer: The Addition of Systemic Chemotherapy to Radiotherapy Led to an Observed Improvement in Survival—A Single Centre Experience and Review of the Literature

    Natalie M. Lowe

    2014-01-01

    Full Text Available Introduction. Anaplastic thyroid carcinoma (ATC is rare yet accounts for up to 50% of all thyroid cancer deaths. This study reviews outcomes of patients with confirmed ATC referred to a tertiary oncology centre plus reviews the literature to explore how poor outcomes may be improved. Materials and Methods. The management and outcomes of 20 patients with ATC were reviewed. Results. Median age at diagnosis was 69.5 years. 19 patients died due to ATC, 40% of whom died from asphyxiation. Median survival for all cases was 59 days. Patients who had previous surgery prior to other treatment modalities had a longer median survival overall compared to those who had not had previous surgery (142 days compared to 59 days and produced the one long-term survivor. Chemotherapy followed by radiotherapy (without previous surgery was associated with longer median survival (220 days. Palliative radiotherapy alone did not decrease the rate of death by asphyxiation when compared to other single modality treatments. Conclusion. Multimodality treatment including surgery when feasible remains the best strategy to improve survival and prevent death from asphyxiation in the management of ATC. The addition of chemotherapy to our institutional protocol led to improved survival but prognosis remains very poor.

  5. Prospective randomised trial for the evaluation of the efficacy of low vs. high dose I-131 for post operative remnant ablation in differentiated thyroid cancer

    This study was performed under the auspices of IAEA project (i) to evaluate the efficacy of low (50 mCi) vs. high (100 mCi) dose I-131 for post operative remnant ablation in differentiated thyroid cancer and (ii) to search for factors associated with successful ablation. There were 138 cases of either papillary or follicular type without evidence of any metastasis. All patient had undergone at least subtotal thyroidectomy. Seventy-five were randomised to be treated with high dose and 63 with low dose I-131. Pretreatment total body scan and 24 hour-neck uptake were performed using 1 mCi of I-131, together with serum T4, TSH, Tg and antiTg. The criteria for successful ablation were absence of discrete thyroid bed activity in total body scan done using 3 mCi of I-131, 48-72 hour-neck uptake of less than 0.2% and serum Tg of less than 10 ng/ml. in the follow up done after 6-8 months of therapy. All patient characteristics were not significantly different between the two randomized groups. The overall successful ablation of the two groups was 76.8% (106/138). The success rate of therapy for each group is presented. High dose (100 mCi) I-131 is more efficient than low dose (50 mCi) for remnant ablation, even in cases with low neck uptake i.e. less than 10%. Logistic regression analysis confirmed the significant influence of ablative dose on the outcome with 4 times more chance of success using the high dose rather than the low dose. Baseline serum T4 and TSH were also associated with successful ablation with 1.4 times more chance of success with each 1 unit (mg/dl) of T4 decrease and 1.2 times with 10 units (mU/ml) of TSH increase. This might be, at least partly, due to good correlation between T4, TSH and the remnant mass

  6. Robotic Surgery for Thyroid Disease

    Lee, Jandee; Chung, Woong Youn

    2013-01-01

    Robotic surgery is an innovation in thyroid surgery that may compensate for the drawbacks of conventional endoscopic surgery. A surgical robot provides strong advantages, including three-dimensional imaging, motion scaling, tremor elimination, and additional degrees of freedom. We review here recent adaptations, experience and applications of robotics in thyroid surgery. Robotic thyroid surgeries include thyroid lobectomy, total thyroidectomy, central compartment neck dissection, and radical ...

  7. Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956)- An Assessment of Quantities released, Off-Site Radiation Doses, and Potential Excess Risks of Thyroid Cancer, Volume 1

    In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel appointed by Tennessee's Commissioner of Health. One of the major contaminants studied in the dose reconstruction was radioactive iodine, which was released to the air by X-10 (now called Oak Ridge National Laboratory) as it processed spent nuclear reactor fuel from 1944 through 1956. The process recovered radioactive lanthanum for use in weapons development. Iodine concentrates in the thyroid gland so health concerns include various diseases of the thyroid, such as thyroid cancer. The large report, ''Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956) - An Assessment of Quantities Released, Off-site Radiation Doses, and Potential Excess Risks of Thyroid Cancer,'' is in two volumes. Volume 1 is the main body of the report, and Volume 1A, which has the same title, consists of 22 supporting appendices. Together, these reports serve the following purposes: (1) describe the methodologies used to estimate the amount of iodine-131 (I-131) released; (2) evaluate I-131's pathway from air to vegetation to food to humans; (3) estimate doses received by human thyroids; (4) estimate excess risk of acquiring a thyroid cancer during ones lifetime; and (5) provide equations, examples of historical documents used, and tables of calculated values. Results indicate that females born in 1952 who consumed milk from a goat pastured a few miles east of X-10 received the highest doses from I-131 and would have had the highest risks of contracting thyroid cancer. Doses from cow's milk are considerably less . Detailed

  8. Does amifostine have radioprotective effects on salivary glands in high-dose radioactive iodine-treated differentiated thyroid cancer

    Ma, Chao; Wang, Guoming; Zuo, Shuyao [Qingdao University, Department of Nuclear Medicine, Affiliated Hospital, Medical College, Qingdao, Shandong Province (China); Xie, Jiawei [Qingdao University, Medical College, Qingdao (China); Jiang, Zhongxin [Qingdao University, Affiliated Hospital, Medical College, Qingdao (China)

    2010-09-15

    To assess the effects of amifostine on salivary glands in radioactive iodine-treated differentiated thyroid cancer. We searched the MEDLINE, EMBASE and the Cochrane Library for randomized controlled clinical trials which compared the effects of amifostine with those of placebo or acid-stimulating agents. Two randomized controlled clinical trials with a total of 130 patients were included. Both studies had a low risk of bias. There were no statistically significant differences between the effects of amifostine and acid-stimulating agents on the incidence of xerostomia (RR 0.24, 95% CI 0.01 to 9.52), the decrease of scintigraphically measured uptake of {sup 99m}Tc by the parotid (RR 0.30, 95% CI -2.28 to 2.88) or submandibular glands (RR 1.90, 95% CI -1.46 to 5.26) at 12 months, or the reduction in blood pressure (RR 5.00, 95% CI 0.25 to 99.16). Neither of the included trials investigated death from any cause, morbidity, health-related quality of life or costs. The results of two randomized controlled clinical trials suggest that amifostine has no significant radioprotective effects on salivary glands in radioactive iodine treatment of differentiated thyroid cancer. The use of acid-stimulating agents to increase salivation should remain the first choice during radioactive iodine treatment of differentiated thyroid cancer. Patients should also be well informed of the importance of hydration and acid stimulation. (orig.)

  9. Global skeletal uptake of technetium-99m methylene diphosphonate in female patients receiving suppressive doses of L-thyroxine for differentiated thyroid cancer

    This study was carried out in order to investigate the possible detrimental effects on bone of levothyroxine (l-T4) suppressive therapy in female patients who had undergone surgery for differentiated thyroid cancer (DTC). Twenty female (14 premenopausal and 6 postmenopausal) patients receiving l-T4 suppressive therapy for DTC were studied. The sample was selected in such a way as to avoid factors influencing bone metabolism other than l-T4. All patients were monitored by sensitive thyroid-stimulating hormone, free triiodothyronine and free thyroxine assays throughout the follow-up. Nineteen healthy (12 premenopausal and 7 postmenopausal) matched women served as controls. In all subjects bone turnover was evaluated by the measurement of global skeletal uptake of technetium-99m methylene diphosphonate (GSU); bone mineral density (BMD) was measured by quantitative computed tomography at the lumbar spine (LS) and by dual-energy X-ray absorptiometry both at the LS and at three femoral sites: the femoral neck, Ward's triangle and the greater trochanter. No significant difference was found in either GSU or BMD between patients (treated for an average period of 68 months) and controls in the whole sample or in any subgroup. Furthermore, no correlations were found between either GSU or BMD and the duration of therapy, daily doses of l-T4 or results of thyroid function tests. Our data show that carefully monitored l-T4 therapy does not influence skeletal turnover (directly reflected by GSU) or the bone density of the spine and femur. (orig.)

  10. The clinical impact of 18F-FDG PET/CT to detect suspicious recurred thyroid cancer with differentiated type before high dose radioactive iodine therapy

    The purpose of this study was to evaluate the usefulness of 18F-FDG PET/CT (PET/CT) in suspicious recurred thyroid cancer before high dose of radioactive iodine therapy (RAI therapy). PET/CT was performed after injecting 370-555MBq of 18F-FDG in 23 patients prior to RAI therapy. RAI therapy (212 58 mCi) was performed, and thyroglobulin (Tg) and anti-thyroglobulin antibody (anti-TG ab) during TSH stimulation was measured. The interval between PET/CT and RAI scan was 41 50 day. 15 patients were confirmed as recurred thyroid cancer (pathologic diagnosis: 10), whereas 8 patients were diagnosed as remission status (pathologic diagnosis: 3). PET/CT had 80.0% (12/15) of sensitivity and 75.0% (6/8) of specificity. TG and RAI scan had 80.0% (12/15) and 75% (6/8), 80% (12/15) and 37.5% (3/8) of sensitivity and specificity, respectively. Combination of PET/CT and TG increased the sensitivity (93.3%; 14/15) and specificity (87.5%; 7/8). There was 25 suspicious lesions (19 malignant lesion, 6 benign lesion) in lesion-based study. PET/CT had 84.5% and 83.3% of sensitivity and specificity but RAI scan had 89.5% and 16.7%, respectively. Five false positive sites of RAI scan were diagnosed as fungus ball of lung, calcified mediastinal LN, and post op induced change such as suture granuloma. PET/CT revealed 80% (3/5) of them as benign lesions. Even though PET/CT had similar sensitivity with high dose of RAI scan, it had a better discriminating nature to detect benign lesion. We could diminish the unnecessary high dose of RAI therapy using FDG PET/CT