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Paudel J, Bhattarai B. Standardizing Normal Reference Value for Thyroid Uptake of Technetium-99m Pertechnetate in Nepalese Population. World J Nucl Med 2024; 23:25-32. [PMID: 38595834 PMCID: PMC11001445 DOI: 10.1055/s-0044-1779283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024] Open
Abstract
Objective Changes in normal reference values of thyroid uptake for iodine have been reported due to geographical and chronological fluctuations in dietary iodine intake in different populations. Nepal is a country with mixed ethnicity, with access to dietary iodine in the form of successful universal salt iodination program by the government of Nepal since 1973. The aim of this study was to establish the normal reference values for thyroid uptake of technetium-99m (Tc-99m) pertechnetate in the Nepalese population in iodine sufficiency era. Methods We prospectively evaluated 52 clinically and biochemically euthyroid participants (46 females and 6 males) with age range from 20 to 71 years who underwent a thyroid Tc-99m pertechnetate scan and uptake between December 2019 to November 2023 in the Department of Nuclear Medicine, Chitwan Medical College fulfilling inclusion/exclusion criteria. Biochemical thyroid function tests were reviewed and Tc-99m pertechnetate thyroid uptake values were determined for each patient. Blood was withdrawn for thyroid hormone assessment. Euthyroid participants were then administered 3.5 to 4.5 mCi of Tc-99m pertechnetate intravenously and their percentage thyroid uptake was calculated after 20 minutes. Results The mean and median uptake of Tc-99m pertechnetate in euthyroid patients were 1.26 and 0.85%, respectively, and the interquartile range was 0.7 to 1.7%. The normal reference uptake value for Tc-99m pertechnetate in the studied population ranged between 0.3 and 3.6%. The fifth and 95th percentiles for pertechnetate uptake were 0.5 and 2.9%, respectively. Conclusion The normal reference range for Tc-99m pertechnetate thyroid uptake in Nepalese population was 0.5 to 2.9% that is lower than the currently accepted international standard of 0.75 to 4.5%. Uptake also increased with increasing age. This study highlights the importance of periodically redefining the geographic location specific normal thyroid uptake reference values.
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Affiliation(s)
- Jiwan Paudel
- Department of Nuclear Medicine, Chitwan Medical College, Bharatpur, Nepal
| | - Babita Bhattarai
- Nepal Army Institute of Health Sciences, Bhandarkhal, Saanobharyang, Nepal
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Serrano B, Amblard R, Beaumont T, Hugonnet F, Dietz M, Berthier F, Garnier N, Villeneuve R, Nataf V, Mocquot F, Montemagno C, Faraggi M, Paulmier B. Quantitative analysis of 99mTc-pertechnetate thyroid uptake with a large-field CZT gamma camera: feasibility and comparison between SPECT/CT and planar acquisitions. EJNMMI Phys 2023; 10:45. [PMID: 37522931 PMCID: PMC10390438 DOI: 10.1186/s40658-023-00566-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023] Open
Abstract
PURPOSE The main objective of this study was to evaluate the ability of a large field Cadmium Zinc Telluride (CZT) camera to estimate thyroid uptake (TU) on single photon emission computed tomography (SPECT) images with and without attenuation correction (Tomo-AC and Tomo-NoAC) compared with Planar acquisition in a series of 23 consecutive patients. The secondary objective was to determine radiation doses for the tracer administration and for the additional Computed Tomography (CT) scan. METHODS Cross-calibration factors were determined using a thyroid phantom, for Planar, Tomo-AC and Tomo-NoAC images. Then Planar and SPECT/CT acquisitions centered on the thyroid were performed on 5 anthropomorphic phantoms with activity ranging from 0.4 to 10 MBq, and 23 patients after administration of 79.2 ± 3.7 MBq of [99mTc]-pertechnetate. We estimated the absolute thyroid activity (AThA) for the anthropomorphic phantoms and the TU for the patients. Radiation dose was also determined using International Commission on Radiological Protection (ICRP) reports and VirtualDoseTMCT software. RESULTS Cross-calibration factors were 66.2 ± 4.9, 60.7 ± 0.7 and 26.5 ± 0.3 counts/(MBq s), respectively, for Planar, Tomo-AC and Tomo-NoAC images. Theoretical and estimated AThA for Planar, Tomo-AC and Tomo-NoAC images were statistically highly correlated (r < 0.99; P < 10-4) and the average of the relative percentage difference between theoretical and estimated AThA were (8.6 ± 17.8), (- 1.3 ± 5.2) and (12.8 ± 5.7) %, respectively. Comparisons between TU based on different pairs of images (Planar vs Tomo-AC, Planar vs Tomo-NoAC and Tomo-AC vs Tomo-NoAC) showed statistically significant correlation (r = 0.972, 0.961 and 0.935, respectively; P < 10-3). Effective and thyroid absorbed doses were, respectively (0.34CT + 0.95NM) mSv, and (3.88CT + 1.74NM) mGy. CONCLUSION AThA estimation using Planar and SPECT/CT acquisitions on a new generation of CZT large-field cameras is feasible. In addition, TU on SPECT/CT was as accurate as conventional planar acquisition, but the CT induced additional thyroid exposure. Trial registration Name of the registry: Thyroid Uptake Quantification on a New Generation of Gamma Camera (QUANTHYC). TRIAL NUMBER NCT05049551. Registered September 20, 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT05049551?cntry=MC&draw=2&rank=4 .
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Affiliation(s)
- Benjamin Serrano
- Medical Physics Department, Centre Hospitalier Princesse Grace, Monaco, Monaco.
| | - Régis Amblard
- Medical Physics Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Tiffany Beaumont
- Laboratoire d'évaluation de la dose interne, Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, France
| | - Florent Hugonnet
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Matthieu Dietz
- Nuclear Medicine Department, Hospices Civils de Lyon, Lyon, France
| | - Frédéric Berthier
- Department of Biostatistics, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Nicolas Garnier
- Medical Physics Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Rémy Villeneuve
- Medical Physics Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Valérie Nataf
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - François Mocquot
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | | | - Marc Faraggi
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
| | - Benoît Paulmier
- Nuclear Medicine Department, Centre Hospitalier Princesse Grace, Monaco, Monaco
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Al-Muqbel KM. Utility of 99m Technetium Pertechnetate Thyroid Scan and Uptake in Thyrotoxic Patients: Jordanian Experience. World J Nucl Med 2023; 22:7-14. [PMID: 36923985 PMCID: PMC10010862 DOI: 10.1055/s-0042-1751053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Objective The objective of this study was to assess our local experience with 99m Technitium thyroid uptake (TcTU) in thyrotoxicosis by examining mean and range of TcTU in both euthyroid patients and thyrotoxic patients. We also wanted to see how well TcTU performed as a substitute for radioiodine thyroid uptake in thyrotoxicosis. Methods The medical records of thyrotoxic patients were reviewed retrospectively. Inclusion criteria were: (1) thyrotoxicosis was proven biochemically, (2) the patient underwent TcTU at the time of thyrotoxicosis diagnosis, (3) at least 6 months of follow-up, and (4) the final diagnosis was documented. All TcTU of euthyroid patients were also reviewed to determine local normal TcTU mean and range. Patients were divided into three groups: Graves' disease, toxic nodular goiter, and subacute thyroiditis. Each patient group's TcTU mean and range were assessed separately. Results There were 209 patients in total (54 euthyroid, 112 Graves' disease, 26 toxic nodules, and 17 patients with subacute thyroiditis). TcTU mean±standard deviation and range for euthyroid patients were 1.5±1.1% and 0.17 to 4.8%, 10.6±10% and 0.43 to 40% for Graves' disease, 4.5±4% and 0.6 to 15% for toxic nodules, and 0.5±0.4% and 0.18 to 1% for subacute thyroiditis. Although one-third of thyrotoxic patients' TcTU values overlapped with the normal TcTU range, the diagnosis was made using qualitative image analysis. Subacute thyroiditis was characterized by poor thyroid visualization, whereas Graves'/toxic nodular goiter was well visualized. Conclusion The mean and range of our local normal TcTU were similar to those previously published. TcTU was a useful alternative to radioiodine in the evaluation of thyrotoxicosis. About two-thirds of the patients had accurate test results. The diagnosis was reached in the remaining one-third of patients by combining quantitative and qualitative image features. This method allowed us to stop giving radioiodine to our patients, resulting in a significant reduction in patient radiation exposure.
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Affiliation(s)
- Kusai M Al-Muqbel
- Faculty of Medicine, Department of Radiology and Nuclear Medicine, Jordan University of Science and Technology, Irbid, Jordan
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O'Doherty J, Jauregui-Osoro M, Brothwood T, Szyszko T, Marsden PK, O'Doherty MJ, Cook GJR, Blower PJ, Lewington V. 18F-Tetrafluoroborate, a PET Probe for Imaging Sodium/Iodide Symporter Expression: Whole-Body Biodistribution, Safety, and Radiation Dosimetry in Thyroid Cancer Patients. J Nucl Med 2017; 58:1666-1671. [PMID: 28385795 PMCID: PMC6205602 DOI: 10.2967/jnumed.117.192252] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 04/01/2017] [Indexed: 11/16/2022] Open
Abstract
We report the safety, biodistribution, and internal radiation dosimetry, in humans with thyroid cancer, of 18F-tetrafluoroborate (18F-TFB), a novel PET radioligand for imaging the human sodium/iodide symporter (hNIS). Methods: Serial whole-body PET scans of 5 subjects with recently diagnosed thyroid cancer were acquired before surgery for up to 4 h after injection of 184 ± 15 MBq of 18F-TFB. Activity was determined in whole blood, plasma, and urine. Mean organ-absorbed doses and effective doses were calculated via quantitative image analysis and using OLINDA/EXM software. Results: Images showed a high uptake of 18F-TFB in known areas of high hNIS expression (thyroid, salivary glands, and stomach). Excretion was predominantly renal. No adverse effects in relation to safety of the radiopharmaceutical were observed. The effective dose was 0.0326 ± 0.0018 mSv/MBq. The critical tissues/organs receiving the highest mean sex-averaged absorbed doses were the thyroid (0.135 ± 0.079 mSv/MBq), stomach (0.069 ± 0.022 mSv/MBq), and salivary glands (parotids, 0.031 ± 0.011 mSv/MBq; submandibular, 0.061 ± 0.031 mSv/MBq). Other organs of interest were the bladder (0.102 ± 0.046 mSv/MBq) and kidneys (0.029 ± 0.009 mSv/MBq). Conclusion: Imaging using 18F-TFB imparts a radiation exposure similar in magnitude to many other 18F-labeled radiotracers. 18F-TFB shows a biodistribution similar to 99mTc-pertechnetate, a known nonorganified hNIS tracer, and is pharmacologically and radiobiologically safe in humans. Phase 2 trials for 18F-TFB as an hNIS imaging agent are warranted.
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Affiliation(s)
- Jim O'Doherty
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Maite Jauregui-Osoro
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Teresa Brothwood
- Department of Nuclear Medicine, Guy's & St. Thomas' Hospital NHS Foundation Trust, Great Maze Pond, London, United Kingdom
| | - Teresa Szyszko
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Paul K Marsden
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Michael J O'Doherty
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Gary J R Cook
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Philip J Blower
- PET Imaging Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, United Kingdom; and
| | - Val Lewington
- Department of Nuclear Medicine, Guy's & St. Thomas' Hospital NHS Foundation Trust, Great Maze Pond, London, United Kingdom
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Abstract
AIM A national audit of quantitative thyroid uptake imaging was conducted by the Nuclear Medicine Software Quality Group of the Institute of Physics and Engineering in Medicine in 2014/2015. The aims of the audit were to measure and assess the variability in thyroid uptake results across the UK and to compare local protocols with British Nuclear Medicine Society (BNMS) guidelines. PARTICIPANTS AND METHODS Participants were invited through a combination of emails on a public mailbase and targeted invitations from regional co-ordinators. All participants were given a set of images from which to calculate quantitative measures and a spreadsheet for capturing results. The image data consisted of two sets of 10 anterior thyroid images, half of which were acquired after administration of Tc-pertechnetate and the other half after administration of I-iodide. Images of the administration syringes or thyroid phantoms were also included. RESULTS In total, 54 participants responded to the audit. The median number of scans conducted per year was 50. A majority of centres had at least one noncompliance in comparison with BNMS guidelines. Of most concern was the widespread lack of injection-site imaging. Quantitative results showed that both intersite and intrasite variability were low for the Tc dataset. The coefficient of quartile deviation was between 0.03 and 0.13 for measurements of overall percentage uptake. Although the number of returns for the I dataset was smaller, the level of variability between participants was greater (the coefficient of quartile deviation was between 0.17 and 0.25). CONCLUSION A UK-wide audit showed that thyroid uptake imaging is still a common test in the UK. It was found that most centres do not adhere to all aspects of the BNMS practice guidelines but that quantitative results are reasonably consistent for Tc-based scans.
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Lee H, Kim JH, Kang YK, Moon JH, So Y, Lee WW. Quantitative single-photon emission computed tomography/computed tomography for technetium pertechnetate thyroid uptake measurement. Medicine (Baltimore) 2016; 95:e4170. [PMID: 27399139 PMCID: PMC5058868 DOI: 10.1097/md.0000000000004170] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/04/2016] [Accepted: 06/03/2016] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVES Technetium pertechnetate (TcO4) is a radioactive tracer used to assess thyroid function by thyroid uptake system (TUS). However, the TUS often fails to deliver accurate measurements of the percent of thyroid uptake (%thyroid uptake) of TcO4. Here, we investigated the usefulness of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) after injection of TcO4 in detecting thyroid function abnormalities. MATERIALS AND METHODS We retrospectively reviewed data from 50 patients (male:female = 15:35; age, 46.2 ± 16.3 years; 17 Graves disease, 13 thyroiditis, and 20 euthyroid). All patients underwent TcO4 quantitative SPECT/CT (185 MBq = 5 mCi), which yielded %thyroid uptake and standardized uptake value (SUV). Twenty-one (10 Graves disease and 11 thyroiditis) of the 50 patients also underwent conventional %thyroid uptake measurements using a TUS. RESULTS Quantitative SPECT/CT parameters (%thyroid uptake, SUVmean, and SUVmax) were the highest in Graves disease, second highest in euthyroid, and lowest in thyroiditis (P < 0.0001, Kruskal-Wallis test). TUS significantly overestimated the %thyroid uptake compared with SPECT/CT (P < 0.0001, paired t test) because other TcO4 sources in addition to thyroid, such as salivary glands and saliva, contributed to the %thyroid uptake result by TUS, whereas %thyroid uptake, SUVmean and SUVmax from the SPECT/CT were associated with the functional status of thyroid. CONCLUSIONS Quantitative SPECT/CT is more accurate than conventional TUS for measuring TcO4 %thyroid uptake. Quantitative measurements using SPECT/CT may facilitate more accurate assessment of thyroid tracer uptake.
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Affiliation(s)
- Hyunjong Lee
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul
- World Class University, Department of Molecular Medicine and Biopharmaceutical Science, Graduate School of Convergence Science and Technology, Seoul National University, Suwon
| | - Ji Hyun Kim
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul
| | - Yeon-koo Kang
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul
| | - Jae Hoon Moon
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine
| | - Young So
- Department of Nuclear Medicine, Konkuk University Medical Center
| | - Won Woo Lee
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul
- Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
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Kidokoro-Kunii Y, Emoto N, Cho K, Oikawa S. Analysis of the factors associated with Tc-99m pertechnetate uptake in thyrotoxicosis and graves' disease. J NIPPON MED SCH 2008; 73:10-7. [PMID: 16538017 DOI: 10.1272/jnms.73.10] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To determine the factors associated with 20 minute Tc-99m pertechnetate thyroid uptake, we examined all patients in whom thyrotoxicosis was diagnosed at Chiba-Hokusoh Hospital, Nippon Medical School from 2001 April through 2003 March. Patients with thyrotoxicosis diagnosed during this period were 57 with Graves' disease (76%), 11 with transient hyperthyroxinemia (TH)(14.7%), and 7 with subacute thyroiditis (SAT)(9.3%). The uptake of Tc-99m ranged from 0.97% to 40.1% in Graves' disease and from 0.15% to 0.8% in TH. Although TH may include spontaneous resolution of Graves' disease as well as painless thyroiditis, no treatment was necessary for these patients. Uptake in all patients with SAT was less than 0.5%. There were significant correlations between the level of Tc-99m uptake and the levels of free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH)-binding inhibitory immunoglobulin (TBII), and thyroid stimulating antibody (TSAb) in patients with Graves' disease. Older patients with Graves' disease showed lower uptake than did younger patients. Both Tc-99m pertechnetate uptake and TBII levels, but not fT3, fT4 or TSAb levels, at the beginning of antithyroid drug treatment correlated significantly with the duration of treatment until the daily dose of methimazole reached 5 mg. These data suggest that Tc-99m pertechnetate uptake reflects the severity of Graves' disease and its response to the medical treatment and that antithyroid drug therapy is not necessary when the uptake is less than 0.9%.
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Affiliation(s)
- Yo Kidokoro-Kunii
- Department of Medicine, Chiba-Hokusoh Hospital, Nippon Medical School, 1715 Kamagari, Inba-gun, Inba-mura, Japan
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Espineira MD, Mol J, Peeters M, Pollak Y, Iversen L, Dijk J, Rijnberk A, Kooistra H. Assessment of Thyroid Function in Dogs with Low Plasma Thyroxine Concentration. J Vet Intern Med 2007. [DOI: 10.1111/j.1939-1676.2007.tb02924.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Daniel GB, Sharp DS, Nieckarz JA, Adams W. Quantitative thyroid scintigraphy as a predictor of serum thyroxin concentration in normal and hyperthyroid cats. Vet Radiol Ultrasound 2002; 43:374-82. [PMID: 12175003 DOI: 10.1111/j.1740-8261.2002.tb01021.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Quantitative thyroid scintigraphy using pertechnetate was performed in 43 cats with various T4 concentrations and compared to eight normal control cats. Quantitative parameters included percentage dose uptake of the radioisotope by the thyroid, thyroid:salivary ratio and rate of thyroid uptake. All cats were anesthetized for the scan, and images were obtained using both low-energy all purpose (LEAP) and pinhole collimators. All quantitative parameters were significantly correlated to the serum T4 concentration, but the best correlation was obtained using the 20-minute thyroid:salivary ratio using only the most intense of the two thyroid lobes. The thyroid:salivary ratio was a good predictor of the metabolic status of the thyroid.
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Affiliation(s)
- Gregory B Daniel
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville 37901-1071, USA
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Ramos CD, Zantut Wittmann DE, Etchebehere ECSDC, Tambascia MA, Silva CAM, Camargo EE. Thyroid uptake and scintigraphy using 99mTc pertechnetate: standardization in normal individuals. SAO PAULO MED J 2002; 120:45-8. [PMID: 11994772 PMCID: PMC11146234 DOI: 10.1590/s1516-31802002000200004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CONTEXT Thyroid uptake and scintigraphy using 99mTc-pertechnetate has proven to be more advantageous than with 131I-iodide, since the images have better quality, the procedure is faster and the patient is submitted to a lower radiation dose. OBJECTIVE The purpose of this study was to standardize a simple and fast methodology for performing thyroid uptake and scintigraphy and to determine the normal values for 99mTc- pertechnetate uptake. TYPE OF STUDY Prospective, non-randomized. SETTING Division of Nuclear Medicine, Department of Radiology, School of Medical Sciences, Campinas State University. PARTICIPANTS The study consisted of 47 normal individuals, 30 women and 17 men, with ages ranging from 19 to 61 years (mean of 33 years). PROCEDURES The laboratory assessment of thyroid function consisted of serum dosages of ultra-sensitive thyroxin and thyrotrophin. Twenty minutes after an intravenous injection of 10 mCi (370 MBq) of 99mTc-pertechnetate, the images were obtained on a computerized scintillation camera equipped with a low-energy high-resolution parallel hole collimator. RESULTS All the individuals were euthyroid both on clinical and laboratory evaluation. The baseline thyroid 99mTc-pertechnetate uptake ranged from 0.4 to 1.7%. The uptake values obtained in these normal individuals showed that 95% presented a thyroid uptake that ranged from 0.4 to 1.5% of the injected dose. CONCLUSION The assessment of thyroid structure and function using 99mTc-pertechnetate is a simple, fast and efficient method, which could easily become a part of the routine studies in nuclear medicine laboratories.
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Affiliation(s)
- Celso Darío Ramos
- Division of Nuclear Medicine, Department of Radiology, School of Medical Sciences, Campinas State University, Campinas, Brazil.
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Adams WH, Daniel GB, Petersen MG, Young K. Quantitative 99mTc-pertechnetate thyroid scintigraphy in normal beagles. Vet Radiol Ultrasound 1997; 38:323-8. [PMID: 9262690 DOI: 10.1111/j.1740-8261.1997.tb00862.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study was done to investigate the validity of published canine thyroid/salivary (T/S) ratios of approximately 1 in normal dogs and to determine thyroid uptake of 99mTc-pertechnetate (pertechnetate) measured as percent uptake of injected dose. These parameters were evaluated in 13 Beagle dogs over a 4 hour period. Mean +/- standard deviation (SD) and median T/S ratios of 1.2 +/- 0.3 and 1.1 were essentially the same at twenty minutes and 1 hour. T/S values ranged from 0.9 to 2.2 at 20 minutes and from 0.8 to 2.4 at 1 hour. T/S ratio values progressively declined over the subsequent time intervals with mean +/- SD and median values of 0.6 +/- 0.2 and 0.6, respectively, measured at 4 hours. The mean +/- SD maximum percent dose uptake of pertechnetate within the thyroid gland was 0.55% +/- 0.15% with a range of 0.28% to 0.90%. The mean +/- SD time interval from injection of pertechnetate to maximum uptake within the thyroid gland was 160 +/- 55 minutes with a range 31-240 minutes. The data derived from this study of normal dogs may be useful in the evaluation of dogs with thyroidal diseases including hypothyroidism.
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Affiliation(s)
- W H Adams
- Department of Small Animal Clinical Sciences, University of Tennessee, College of Veterinary Medicine, Knoxville 37901-1071, USA
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Abstract
Patients with Graves disease were prospectively followed by means of three 99mtechnetium thyroid uptake ratios. These three ratios were greater than 90% sensitive and specific for the detection of hyperthyroidism in the patient with untreated Graves disease. Twelve of 15 patients experienced prolonged remission after normalization of the ratios. These ratios exhibit significant linear correlation with serum thyroxine and triiodothyronine concentrations (r = 0.4-0.6, P less than 0.01) and are a very sensitive index of medical oversuppression of thyroid function.
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Abstract
Toxic nodular goitre is the late result of a slow growth process generating new daughter follicles from the mother follicles of a normal thyroid gland. Since the normal follicular shell is not built up by monoclonal epithelial cells, but rather by cells with widely variable functional equipment, daughter follicles generated by the preferential replication of particular mother follicular cells endowed with a high growth potential, may be different from mother follicles. For instance, the progeny of follicles may have a higher or lower iodine metabolism than their progenitor follicles. Some of the newly generated follicles have a high autonomous, i.e. TSH-independent, iodine turnover, while some others have a high autonomous growth potential. The degree of autonomous function is entirely independent of that of growth. In the process of goitrogenesis, newly generated follicles may, in addition, acquire new forms of expressing genetic functions. Such new traits, e.g. a particular growth pattern, may become inheritable and are then passed on from mother to daughter cells. The result is the most characteristic of all hallmarks of nodular goitres, which is the heterogeneity of structure and function between two diseased glands and even between closely adjacent follicles of the same gland. Greatly uneven intrinsic replication rates between different follicular cells and equally varying independency on growth stimuli account for regional differences in goitre growth. This, together with a network of fibrous scars interfering with unimpeded expansion of the growing follicle population, invariably produces a nodular growth pattern of the goitre. TSH certainly does not account for the growth of this type of goitre. Instead, a number of thyroid growth factors, including growth-stimulating immunoglobulins akin to those found in Graves' disease, have been discovered in recent years. Once the number of follicular cells with high intrinsic growth potential has become large enough under the impact of extrathyroidal growth stimuli, goitre growth may become autonomous and self-perpetuating. Whether or not a nodular goitre will produce thyrotoxicosis is a function of the number of follicles with high intrinsic iodine turnover which happen to be generated in the course of goitrogenesis. In contrast to thyrotoxicosis in Graves' disease, hyperthyroidism in nodular goitre is a very slowly progressing, insidiously evolving complication.
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