Search

Purpose There is currently no consensus on which protective strategy is most effective to prevent I-131 uptake in the thyroid during medical interventions in children. We aimed to collect the best available evidence to determine which pharmacological intervention is most effective in protecting the thyroid gland from damage by radioactive iodine (RAI). Methods Literature searches were performed using PubMed, Embase, OLDMEDLINE, and the Cochrane Central Register of Controlled Trials. Only original studies were included (1950–2022). Studies comparing pharmacological prevention of the thyroid against RAI uptake or occurrence of hypothyroidism, thyroid nodule or thyroid cancer were included. Included studies were graded according to the Grading of Recommendations Assessment, Development and Evaluation considerations. Pharmacological interventions were compared for effectiveness on reduction of thyroidal intake or relevant clinical thyroidal outcomes. Results Forty studies were included. Quality of included studies was low and many different outcome variables were used, making meta-analysis impossible. In 81% of studies, the pharmacological intervention could not prevent RAI uptake or thyroid damage. The administration of potassium iodide (KI) 1 h before exposure to RAI seemed most effective to reduce thyroidal uptake, however, hypothyroidism was reported in up to 64% as well as several cases of thyroid carcinoma. The combination of KI, thyroxine and thiamazole reduced RAI uptake and occurrence of hypothyroidism; yet, after follow-up of 9 years, still 50% of patients developed hypothyroidism. KI with potassium perchlorate showed hypothyroidism to occur in up to 12% of patients after short follow-up time. Conclusions The lack of well-designed studies impairs making strong recommendations on the optimal way to prevent thyroid damage when using radioactive coupled ligands for medical interventions. To improve the protection of the thyroid against radiation damage by I-131, well-designed randomized clinical trials with sufficient follow-up time, comparing new protective strategies’ effects on valid and well-defined thyroid outcomes are needed.

Chulalongkorn Medical Journal, 67, 2, 091-096

Shang Lin,1 Ya-ru Wei,2 Hong-xiang Yao3 1Department of Nuclear Medicine, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325002, People’s Republic of China; 2Department of Radiology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325002, People’s Republic of China; 3Department of Interventional Radiology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325002, People’s Republic of ChinaCorrespondence: Hong-xiang YaoDepartment of Interventional Radiology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, 109 Xueyuan Western Road, Wenzhou, 325002, Zhejiang, People’s Republic of ChinaEmail lsyhx2004@163.comBackground: Hundreds of studies have reported the application of iodine-131 (I-131) in thyroid carcinoma (THCA) in past years. However, the status of research in the field and other related topics have not been investigated. This study aimed to identify the cooperation of authors, countries, and institutions, as well as explore the hot topics and prospects regarding I-131 therapy in THCA based on previous studies.Methods: Publications from 2010 to 2020 were retrieved from Web of Science Core Collection according to research strategy. Bibliometric analyses were performed using VOSviewer 1.6.15 and CiteSpace 5.7.3 to evaluate and visualize the cooperation network, hot topic, and research frontier.Results: The number of publications showed a trend of fluctuation between 2010 and 2020. We identified 1387 publications related to I-131 therapy in THCA, which were published by 1628 institutions from 82 countries. The largest proportion of publications were emanated from the USA, and the majority of papers were published by Thyroid. Shanghai Jiao Tong University of China contributed the most papers. Although many authors participated in the research of this field, high-yield authors were few. Co-occurrence analysis classified keywords into five clusters, including assessment, efficacy measurement, monitoring, hormone regulation, and guidelines of I-131 therapy. The terms “bone marrow dosimetry and time” were among the latest hotspots. The research frontier topic in I-131 therapy focused on the “P53 and anti-Müllerian hormone”.Conclusion: The attention to I-131 therapy in THCA should be increased considerably. It was necessary to construct active co-operations between authors, countries, and institutions to promote the development of this field. Recent researches referred to the timing and dose assessment of I-131 therapy in THCA. Future studies likely focused on targeted therapy and adverse effects evaluation were worthy of research as well.Keywords: I-131, thyroid carcinoma, bibliometric analysis, hot spots, research trend

In differentiated thyroid cancer (DTC), radioiodine is administered to eliminate residual normal thyroid tissue after thyroidectomy (ablative treatment), to treat residual microscopic disease (adjuvant treatment), and to treat macroscopic or metastatic disease. Currently, treatment of DTC with I-131 is still a matter of controversy due to the absence of prospective clinical trials assessing its benefit in terms of overall survival and recurrence-free interval. The current recommendations of the experts are based on observational retrospective data and on their interpretation of the literature. Pending the results of the prospective trials that are currently underway, the use of I-131 seems to be justified not only in high-risk patients, but also in intermediate-risk and low-risk patients. The guidelines of The American and British Thyroid Association, European and American Societies of Nuclear Medicine, The European Consensus Group and the latest edition of National Comprehensive Cancer Network (NCCN) were considered in drawing up this continuing education document, we also undertook a review of the related scientific literature. (C) 2019 Published by Elsevier Espafia, S.L.U. on behalf of Sociedad Espafiola de Medicina Nuclear e Imagen Molecular.

The systemic delivery of doxorubicin (DOX) to treat osteosarcoma requires an adequate drug concentration to be effective, but in doing so, it raises the risk of increasing organ off-target toxicity and developing drug resistance. Herein, this study reveals a multiple therapeutic nanocarrier delivery platform that overcomes off-target toxicity by providing good specificity and imparting enhanced tumor penetration in a three-dimensional (3D) human MG-63 spheroid model. By synthesizing PEG-PLGA nanoparticles by the double emulsion method, encapsulating DOX and Na131I in the inner core, and conjugating with an epidermal growth factor receptor (EGFR) antibody, it is intended to specifically target human MG-63 cells. The nanocarrier is biocompatible with blood and has good stability characteristics. Na131I encapsulation efficiency was >96%, and radiochemical purity was >96% over 96 h. A DOX encapsulation efficacy of ~80% was achieved, with a drug loading efficiency of ~3%, and a sustained DOX release over 5 days. The nanocarrier EGFR antibody achieved a ~80-fold greater targeting efficacy to MG-63 cells (EGFR+) than fibroblast cells (EGFR−). The targeted multiple therapeutic DIE-NPs have a higher penetration and uptake of Na131I to the 3D model and a ~3-fold higher cytotoxicity than the DOX monotherapy (D-NPs). The co-administration of DOX and Na131I (DIE-NPs) disrupts DNA repair and generates free radicals resulting in DNA damage, triggering the activation of apoptosis pathways. This leads to inhibition of MG-63 cell proliferation and promotes cell cycle arrest in the G0/G1 phase. Furthermore, the PEGylated anti-EGFR functionalized DIE-NPs were found to be biocompatible with red blood cells and to have no adverse effects. This anti-EGFR targeted multifunctional I-131 radio-nanotherapeutic signifies a customizable specific targeted treatment for osteosarcoma.

Changing insights regarding radioiodine (I-131) administration in differentiated thyroid carcinoma (DTC) stir up discussions on the utility of pre-ablation diagnostic scintigraphy (DxWBS). Our retrospective study qualitatively and semi-quantitatively assessed posttherapy I-131 whole-body scintigraphy (TxWBS) data for thyroid remnant size and metastasis. Findings were associated with initial treatment success after nine months, as well as clinical, histopathological, and surgical parameters. Possible management changes were addressed. A thyroid remnant was reported in 89 of 97 (92%) patients, suspicion of lymph node metastasis in 26 (27%) and distant metastasis in 6 (6%). Surgery with oncological intent and surgery by two dedicated thyroid surgeons were independently associated with a smaller remnant. Surgery at a community hospital, aggressive tumor histopathology, histopathological lymph node metastasis (pN1) and suspicion of new lymph node metastasis on TxWBS were independently associated with an unsuccessful treatment. Thyroid remnant size was unrelated to treatment success. All 13 pN1 patients with suspected in situ lymph node metastases on TxWBS had an unsuccessful treatment, opposite 19/31 (61%) pN1 patients without (p = 0.009). Pre-ablative knowledge of these TxWBS findings had likely influenced management in 48 (50%) patients. Additional pre-ablative diagnostics could optimize patient-tailored I-131 administration. DxWBS should be considered, especially in patients with pN1 stage or suspected in situ lymph node metastasis. Dependent on local surgical expertise, DxWBS is not recommended to evaluate thyroid remnant size.

Journal of Associated Medical Sciences, 54, 2, 17 - 21

Changing insights regarding radioiodine (I-131) administration in differentiated thyroid carcinoma (DTC) stir up discussions on the utility of pre-ablation diagnostic scintigraphy (DxWBS). Our retrospective study qualitatively and semi-quantitatively assessed posttherapy I-131 whole-body scintigraphy (TxWBS) data for thyroid remnant size and metastasis. Findings were associated with initial treatment success after nine months, as well as clinical, histopathological, and surgical parameters. Possible management changes were addressed. A thyroid remnant was reported in 89 of 97 (92%) patients, suspicion of lymph node metastasis in 26 (27%) and distant metastasis in 6 (6%). Surgery with oncological intent and surgery by two dedicated thyroid surgeons were independently associated with a smaller remnant. Surgery at a community hospital, aggressive tumor histopathology, histopathological lymph node metastasis (pN1) and suspicion of new lymph node metastasis on TxWBS were independently associated with an unsuccessful treatment. Thyroid remnant size was unrelated to treatment success. All 13 pN1 patients with suspected in situ lymph node metastases on TxWBS had an unsuccessful treatment, opposite 19/31 (61%) pN1 patients without (p = 0.009). Pre-ablative knowledge of these TxWBS findings had likely influenced management in 48 (50%) patients. Additional pre-ablative diagnostics could optimize patient-tailored I-131 administration. DxWBS should be considered, especially in patients with pN1 stage or suspected in situ lymph node metastasis. Dependent on local surgical expertise, DxWBS is not recommended to evaluate thyroid remnant size.

Background: Serum symmetric dimethylarginine (SDMA) is a sensitive renal biomarker for detecting early chronic kidney disease (CKD) in nonhyperthyroid cats, but knowledge regarding its performance in hyperthyroid cats remains limited. Objectives: To determine the relationship between serum SDMA, creatinine and total thyroxine (TT4) concentrations in hyperthyroid cats before (T0) and 3 months after (T1) receiving a PO fixed dose of radioiodine. Animals: Eighty client‐owned hyperthyroid cats. Methods: Prospective cohort study. Serum TT4, and SDMA, creatinine concentrations, and urine specific gravity were measured at T0 and T1. Nonparametric tests were used to determine the relationship among SDMA, and creatinine and TT4 concentrations. Agreement between SDMA and creatinine regarding CKD staging at both time points was assessed using Goodman and Kruskal's gamma statistic. Results: Mean serum SDMA concentration increased after treatment of hyperthyroidism. However, 21 of 75 cats experienced a decrease in SDMA between T0 and T1, whereas creatinine decreased in only 2 cats. A moderate correlation between SDMA and creatinine was seen at T1 (r = 0.53; P < .001) but not at T0 (r = 0.13; P = .25). Where assessable at T1, poor agreement was observed between SDMA and creatinine and CKD stage (Goodman and Kruskal's gamma 0.20; P = .29). Conclusions and clinical importance: Discordant outcomes between SDMA and creatinine after radioiodine treatment in cats with hyperthyroidism suggest extrarenal factors may interfere with the reliability of SDMA to adequately reflect renal function. As a result, SDMA should not be interpreted in isolation in hyperthyroid cats treated with radioiodine.

WOS: 000446711000001, PubMed ID: 30317832, Objective: Radioiodine is the most specific radionuclide for differentiated thyroid carcinoma (DTC) imaging. Despite its high specificity and sensitivity, false-positive I-131 uptake could be seen on whole body scan (WBS) that may lead to misdiagnosis and unnecessary radioiodine treatment. In this study, we aimed to present the I-131 WBS and concomitant single photon emission computed tomography/computed tomography (SPECT/CT) images of unexpected false-positive radioiodine uptake along with the patients' clinical outcomes and the contribution of SPECT/CT imaging. Methods: I-131 WBSs of 1507 patients with DTC were retrospectively reviewed, and anticipated I-131 uptakes (like in breasts or thymus) were excluded from the study. The unexpected false-positive I-131 uptakes with concomitant SPECT/CT imaging were included in the study. Results: Twenty-one patients had 23 unexpected I-131 uptakes on WBS and concomitant SPECT/CT imaging. The vast majority (87%) of these cases were seen on post-therapeutic I-131 WBS. Most of the false-positive I-131 uptakes could be explained by SPECT/CT and radiologic findings, and were secondary to non-thyroid conditions (bronchiectasis, lung infection, subcutaneous injection into gluteal fatty tissue, aortic calcification, benign bone cyst, vertebral hemangioma, recent non-thyroid surgical procedure site, rotator cuff injury, mature cystic teratoma and ovarian follicle cyst). However, the possible reasons of 9 false-positive I-131 uptakes could not be explained by radiologic findings. Conclusion: We suggest that false-positive I-131 uptake and its underlying mechanisms (inflammation, trapping, increased perfusion, etc.) must be kept in mind in patients with thyroid cancer and unexpected findings must be considered together with serum thyroglobulin levels, SPECT/CT and radiologic findings in order to avoid misdiagnosis and unnecessary radioiodine treatment.

Radioiodine (131I) therapy is the mainstay of treatment for patients who had undergone total thyroidectomy for well differentiated thyroid carcinoma. Increased fluid intake has always been encouraged to minimize the risk of non-target organ exposure to I-131radiation. This study aimed to determine the minimum amount of fluids needed for patients to have the fastest time to achieve permissible level for release after high dose I-131therapy. Methodology: All the patients who were treated with high dose I-131from 18th January 2016 till 31st December 2016 in Hospital Pulau Pinang, Malaysia were recruited. The data from 126 patients on thyroxine hormone withdrawal (THW) group and 18 patients on recombinant human thyroid stimulating hormone (rhTSH) group were analysed. There is no change in patient management in terms of preparation, dose or post therapy whole-body scan. Fluid intake of patients were monitored strictly and whole-body retention of I-131are measured using ionizing chamber meter immediately after ingestion of I-131then at 1 hour, 24 hours, 48 hours, 72 hours and 96 hours. Results: The median time to achieve permissible release limit (50 μSV/hr at 1 meter) was 21.6 hours and 22.1 hours post-ingestion of I-131in the THW and rhTSH group respectively. The minimum amount of fluid needed to reach permissible release limit in the fastest time was 2,103 ml and 2,148ml for the THW and TSH respectively. Conclusion: Clinicians would be able to evidently advise their patient on the amount of fluid to consume and utilize their isolation wards faster to treat more patients.

Objective: Radioiodine (I-131) is an established modality of definitive treatment of hyperthyroidism. In spite of the vast experience available, there are stilt several aspects to be clarified, such as whether fixed or calculated doses should be used. The aim of this study was to assess whether efficacy of this treatment could be improved by implementing a simple dosimetric calculation method including ultrasonographic estimation of thyroid volume and a single measurement of 24-hour I-131 thyroid uptake. Methods: A prospective non-inferiority study was designed to compare two procedures to calculate radioiodine activity: the "semi-fixed" dose method (A), and the,calculated dose method (B). The first consisted of activity escalation (185 MBq steps) based on etiology of hyperthyroidism, I-131 uptake, and treatment objective. The second method was based on the,dosimetric compromise concept, considering 24-hour uptake and thyroid volume as the only factors and using a standard half-life of 5.5 days. The target absorbed dose was 150 Gy, but after a preliminary analysis (first 100 cases) it was increased to 200 Gy in diffuse toxic goiters (DTGs). Results: A total of 212 patients were included. Method B was at least as effective in terms of final and functional outcome, with a trend to more success and less hypothyroidism. In addition, activities administered were significantly lower. Conclusion: In radioiodine therapy of hyperthyroidism, a simple dosimetric method that provided results at least equal to those of a fixed dose-based method, with lower administered activities, could be implemented. (C) 2020 SEEN y SED. Published by Elsevier Espana, S.L.U. All rights reserved.

Traditional nuclear medicine is rapidly being transformed by the evolving concepts in molecular imaging and theranostics. The utility of new approaches in differentiated thyroid cancer (DTC) diagnostics and therapy has not been fully appreciated. The clinical information, relevant to disease management and patient care, obtained by scintigraphy is still being underestimated. There has been a trend towards moving away from the use of radioactive iodine (RAI) imaging in the management of the disease. This paradigm shift is supported by the 2015 American Thyroid Association Guidelines (1). A more systematic and comprehensive understanding of disease pathophysiology and imaging methodologies is needed for optimal utilization of different imaging modalities in the management of DTC. There have been significant developments in radiotracer and imaging technology, clinically proven to contribute to the understanding of tumor biology and the clinical assessment of patients with DTC. The research and development in the field continues to evolve, with expected emergence of many novel diagnostic and therapeutic techniques. The role for nuclear imaging applications will continue to evolve and be reconfigured in the changing paradigm. This article aims to review the clinical uses and controversies surrounding the use of scintigraphy, and the information it can provide in assisting in the management and treatment of DTC.Geleneksel nükleer tıp, moleküler görüntüleme ve teranostik kavramları ile hızla değişmektedir. Ancak bu prosedürlerin değeri diferansiye tiroid kanserleri (DTK) alanında küçümsenmektedir. Bu durum kısmen hastalığa klinik yaklaşımdaki gelişmelere kısmen de klinisyen ve nükleer görüntüleyicilerin bu görüntüleme ile ilgili bilgilerinin eksikliği nedeniyle değerinin anlaşılamamasına bağlıdır. Sonuç olarak, DTK’da sintigrafinin kullanımı açısından veriler ancak sınırlı bir yarar göstermiş, ve yakın zamanda yayımlanan Amerikan Tiroid Birliği yönergesinde (1) de ifade edildiği gibi hastalığın tedavisinde görüntüleme kullanımından uzaklaşma eğilimi doğmuştur. Her ne kadar görüntülemenin değeri tartışmalı olsa da, görüntülemeye ve bunların DTK yönetiminde uygulanmasına daha sofistike bir yaklaşımın gerekliliği ve yararı konusunda evrensel görüş birliği vardır. Radyo-farmasötikler ve teknolojide, DTK nükleer görüntülemesinde yararı kanıtlanan birçok gelişme olmuştur ve bu gelişmeler devam etmektedir. Gelecekte yeni terapötik ve görüntüleme seçeneklerinin ortaya çıkmasıyla birlikte, görüntülemenin yararı yeniden revize edilebilir. Bu makale sintigrafinin kullanımının klinik faydaları ve etrafındaki tartışmalarla birlikte, sağladığı bilgilerin DTK yönetimi ve tedavisindeki etkilerini araştırmaktadır.

Introduction: In iodine-131 (I-131) imaging, the image quality is degraded by scatter and penetration in a collimator. In this work, we assessed the penetrated and the scattered photon fractions in the photopeak energy window using Monte Carlo Simulation code. Materials and Methods: The Siemens Medical System equipped with high-energy collimator was simulated. We evaluated the acceptance angle values on geometric, penetration, and scatter components in a separate file. Binary images in a data file are obtained and each one of them was imported in software ImageJ. Full-width at half-maximum (FWHM) and sensitivity were calculated and compared. Results: The simulation data show that for the acceptance angle value equal to 4.845°, the geometric, scatter, and penetration components were 93.20%, 4.13%, and 2.67%, respectively. Moreover, the resolution is improved (FWHM = 7.21 mm, full width at tenth maximum = 12.36 mm) for a point source at 12 cm from the detector. Conclusion: The small acceptance angle has a major impact on the image quality in I-131 single photon emission computed tomography.

Background: Treatment of differentiated thyroid carcinoma (DTC) often involves administration of radioactive iodine (I-131) for remnant ablation or adjuvant therapy. As DTC has favorable outcome and the incidence is increasing, concerns have been raised about the possible adverse effects of I-131 therapy. We systematically reviewed the literature to examine the risk of intermediate and long-term adverse effects of I-131 therapy in DTC patients. Methods: Multiple electronic databases were searched up to November 2014 for English-language, controlled studies that reported on the risk of salivary gland dysfunction, lacrimal gland dysfunction, gonadal dysfunction, female reproductive outcomes or second primary malignancies (SPM) after I-131 exposure. The certainty of the evidence found was assessed using GRADE. Results: In total, 37 articles met all inclusion criteria, no studies reporting on adverse effects after I-131 treatment focused solely on children. After exposure to I-131 for DTC, patients experienced significantly more frequently salivary gland dysfunction (prevalence range: 16-54%, moderate-level evidence), lacrimal gland dysfunction (prevalence: 11%, low-level evidence), transient male gonadal dysfunction (prevalence: 35-100%, high-level evidence), transient female gonadal dysfunction (prevalence: 28%, low-level evidence) and SPM (prevalence: 2.7-8.7%, moderate-level evidence) compared to unexposed patients. I-131 therapy seems to have no deleterious effects on female reproductive outcomes (very-low level evidence). The prevalence and severity of adverse effects were correlated to increasing cumulative I-131 activity. Conclusion: Treatment with I-131 for DTC may have significant adverse effects, which seem to be dose dependent. These adverse effects of treatment must be balanced when choosing for I-131 therapy in patients with DTC. (C) 2015 Elsevier Ltd. All rights reserved.

Struma ovarii (SO), a rare tumor containing at least 50% of thyroid tissue, represents approximately 5% of all ovarian teratomas; its malignant transformation rate is reported to occur in up to 10% of cases and metastases occur in about 5-6% of them. We describe a 36-year old woman who underwent laparoscopic left annessectomy two years earlier because of an ovarian cyst. Follow-up imaging revealed a right adnexal mass, ascitis and peritoneal nodes that were diagnosed as comprising a malignant SO with peritoneal secondary localizations at histopathology performed after intervention. Restaging with F-18-FDG-PE T/CT scan, abdominal CT and ultrasonography showed abnormalities in the perihepatic region and presacral space and left hypochondrium localizations. The patient underwent thyroidectomy, hepatic nodulectomy and cytoreductive peritonectomy: histopathological examination did not show any malignant disease in the thyroid and confirmed the presence of peritoneal localizations due to malignant SO; molecular analysis detected NRAS Q61K mutation in exon 3, whereas no mutations were identified on the BRAF gene. The patient underwent radioiodine treatment: serum Tg was decreased at first follow-up after three months of I-131-therapy. We believe that our case raises some interesting considerations. First, pathologists should be aware of this entity and should check for the presence of point mutations suggesting an aggressive disease behavior, which could be beneficial for an optimal therapeutic approach. Second, although most of the knowledge in this field comes from case reports, efforts should be made to standardize the management of patients affected by malignant SO, including use of practice guidelines.

Background Struma ovarii is a rare monodermal germ cell tumor where the ovary is comprised of at least half thyroid tissue. This phenomenon may indicate an embryological origin. Case presentation A 30-year old nulliparous woman presented with acute right lower quadrant pain and underwent laparoscopic right salpingo-oophorectomy. The excised ovarian mass showed evidence of struma-derived papillary thyroid carcinoma. Ultrasound of the thyroid showed mild enlargement with two solid nodules. A fine needle aspirate of a thyroid nodule was positive for malignancy and a total thyroidectomy was performed. Microscopic features of the thyroid were consistent with papillary thyroid carcinoma. The two tumours were considered as synchronous independent primaries based on their histological presentation. Conclusions We believe that aggressive surgical management followed by radioiodine therapy is best to reduce recurrence risk and optimize survival. The broad scope of interventions needed to treat malignant struma ovarii require a strong interdisciplinary team.

Radioisotope concentrations (Cs-137 and I-131) in sewage sludge, obtained on a daily basis in the Fukushima city wastewater treatment plant from end of April 2011 until end of December 2013, have been analysed for their evolution with time, and the time series have been compared to similar data from central Europe after the Chernobyl accident. Additionally, daily rainfall data have been considered for Fukushima. The long-term trends for Cs-137 are very similar between Japan and Europe, indicating a decrease of concentration with an initial half-life of about 1 year with a tendency towards a slower decrease at later times. Short-term Cs-137 data indicate a dominating influence of rainfall – each significant rainfall event leads to a sharp increase of sludge Cs-137 concentration. Absolute values (maximum: ca. 6000 Bq kg -1 ) are relatively low compared to Europe after 1986 – this is attributed to the different types of sewer systems: separated in Fukushima, collecting only small amounts of rainfall with the wastewater, mixed in many cities in Europe, collecting rainwater and wastewater in the same sewer. I-131 was detectable during short intervals and at relatively constant maximum concentration (ca. 1000 Bq kg -1 ) during the whole observation period. The origin is suspected to be routine medical application of the isotope, which has been shown to contribute significantly to sewage sludge concentration wherever it is in use.

Objective: Using radioactive iodine (RAI) as the first line therapy for Graves’ hyperthyroidism and as the treatment of choice for relapsed Graves’ disease is increasing in recent times. However, there has been little consensus on the most appropriate dose to use. So this study is to determine the response of hyperthyroidism to fixed doses of 370 MBq and 555 MBq RAI therapies and determine the incidence of hypothyroidism at 6 months post therapy. Methods: Hyperthyroid patients’ case records treated with radioiodine was retrospectively reviewed to determine the response rate of hyperthyroidism to the two fixed dose regimens. Statistical analysis was done with SPSS version 15.0 and the level of statistical significance was taken as p

Objective were to assess efficiency of various I-131 activities on thyroid remnant ablation in thyroid cancer patients. The significance of patients' characteristics, pathologic features and levels of Tg were analyzed. This study included 259 consecutive differentiated thyroid cancer patients, with disease confined to the thyroid, treated with I-131 after total thyroidectomy. Patients were divided into the three groups: 80 patients receiving low [1110-1850 MBq (30-50 mCi)], 121 intermediate [2775 MBq (75 mCi)] and 58 high [3700 MBq (100 mCi)] postoperative I-131 activities. Six to eight months after the application of radioiodine, measurements of TSH, Tg, anti-Tg antibodies (in hypothyroid state) together with ultrasound exam and whole-body scintigraphy were performed. The ablation was significantly more effective (after the first application) in patients receiving 100 mCi of I-131-89.7 % than in patients receiving lower activities (P = 0.016). There was no significant difference in ablation rate between the 30-50 mCi (77.5 %) and 75 mCi (70.2 %) groups. In the group receiving 30-50 mCi, patients with solitary tumors had significantly higher ablation rate (P = 0.038). In patients receiving 75 mCi ablation rates were higher among older patients (P = 0.005), with infiltration of the single lobe (P = 0.005), and with solitary tumor (P = 0.012). The rates of successful ablation after the second application of I-131 (after 12-16 months) amounted to 96, 97 and 96 % in the 30-50, 75 and 100 mCi groups, respectively. The activity of I-131 and age were independent factors for thyroid ablation failure after the first application of I-131 (model of binary logistic regression). The results of remnant ablation were satisfactory with all activities applied. Although after the first application of I-131 the activity of 100 mCi is significantly more effective in thyroid ablation than the administration of 30-50 mCi and 75 mCi, the ablation rates between all the three groups are similar (almost equal) after the second application. Thus, the activity to be administered may depend on patients' characteristics and a detailed consideration of the merits and demerits of each I-131 activity.

Thyroid cancer, divided in the subvarieties of papillary and follicular carcinoma, together also called differentiated thyroid carcinoma (DTC), medullary thyroid carcinoma (MTC) and anaplastic thyroid carcinoma (ATC), is the most common endocrine malignancy. Over the course of the last seven decades multiple molecular nuclear therapies have been tried to treat the various varieties of thyroid cancer. The sodium iodine symporter (NIS) substrate I-131 is a well known and extremely successful agent to treat DTC, but is not successful in treating other thyroid cancer varieties and some de-differentiated DTC tumors. An alternative to I-131 are radioactively labeled somatostatin analogues, which have predominantly been used to target MTC, but may also be effective in some DTC cases. In experimental preclinical studies the re-induction of NIS expression or transfection with recombinant NIS shows some promise for the treatment of ATC and dedifferentiated DTC. Furthermore, several other potential radioactive NIS substrates are developed. In this review, we will extensively discuss the aforementioned established therapeutic modalities and promising new concepts in molecular nuclear therapy of thyroid carcinoma.

ObjectiveThis retrospective study describes the role of serum thyroglobulin (Tg) in relation to tumor characteristics in the prediction of persistent/recurrent disease in patients with differentiated thyroid cancer (DTC) with negative Tg at the time of ablation.DesignBetween 1989 and 2006, 94 out of 346 (27%) patients with DTC had undetectable Tg at the time of 131I ablation and were included in this evaluation. The group of 94 patients consisted of 15 males and 79 females in the age range of 16–89 years with a median follow-up of 8 years (range 1–17). All medical records and follow-up parameters of the 94 patients were evaluated for the occurrence of persistent/recurrent disease. In patients with persistent/recurrent disease hematoxylin-eosin-stained slides of the primary tumors and/or metastatic lesions were also reviewed for histological features including immunostains for Tg.ResultsDuring follow-up, 8 out of 94 (8.5%) patients showed persistent/recurrent disease: in the course of the disease two patients showed Tg positivity, three showed Tg antibody (TgAb) positivity, and the other three showed persistently undetectable Tg and TgAb. Patients who developed Tg and/or TgAb positivity during follow-up had a significantly shorter disease-free survival period when compared with patients with persistently undetectable Tg and TgAb (PConclusionsFollow-up of Tg and TgAb in patients with initially negative Tg and TgAb is useful since a number of patients had shown detectable Tg or TgAb during follow-up indicative for persistent/recurrent disease. Tg and TgAb negativity at the time of ablation is not a predictive determinant for future recurrent status.

Objectives: To compare the results of individual dosimetry in differentiated thyroid cancer patients treated with I-131 at our centre with the established limits and dosimetry results of published studies. Analysis of the optimal number of measurements necessary to reduce the impact of dosimetry for the comfort of the patient and, secondly, on the workload of health workers. Material and methods: Dosimetry was performed in the Nuclear Medicine Department of the University and Polytechnic Hospital La Fe, on 29 patients suffering from differentiated thyroid cancer and treated with activities between 1.02 and 5.51 GBq (mean 2.68 GBq) of I-131. The Spanish Society of Medical Physics (SEFM) protocol was used, based on measurements of external dose rate adjusted to a bi-exponential curve according to a two compartment model. Different dosimetries were performed on each patient, taking different selections of the available measurements in order to find the optimal number. Results: Results are well below the dosimetry limits, and are consistent with those obtained in other centres. The number of measurements can be reduced from 5, as proposed in the SEFM protocol, to 4 without significant loss of accuracy. Further reducing measures may be justified in individual cases. Conclusions: The values obtained for the dosimetry quantities are significantly below the established limits. A reduction in measurements can be assumed at the cost of a moderate increase in uncertainty, benefiting the patient. (C) 2015 Elsevier Espana, S.L.U. and SEMNIM. All rights reserved.

WOS: 000335651700019, PubMed ID: 24761858, Background: Serum thyroglobulin detection plays an essential role during the follow-up of thyroid cancer patients treated with total/near total thyroidectomy and radioiodine ablation. The aim of this retrospective study was to evaluate the relationship between stimulated serum thyroglobulin (Tg) level at the time of high dose I-131 ablation and risk of recurrence, using a three-level classification in patients with differentiated thyroid cancer (DTC) according to the ATA guidelines. Also we investigated the relationship between postoperative stimulated Tg at the time of ablation and DxWBS results at 8-10 months thereafter. Materials and Methods: Patients with radioiodine accumulation were regarded as scan positive (scan+). If there was no relevant pathological radioiodine accumulation or minimal local accumulation in the thyroid bed region, this were regarded as scan negative (scan-) at the time of DxWBS. We classified patients in 3 groups as low, intermediate and high risk group for assessment of risk of recurrence according to the revised ATA guidelines. Also, we divided patients into 3 groups based on the stimulated serum Tg levels at the time of I-131 ablation therapy. Groups 1-3 consisted of patients who had Tg levels of = 10 ng/ml, respectively. Results: A total of 221 consecutive patients were included. In the high risk group according to the ATA guideline, while 45.5% of demonstrated Scan(+) Tg(+), 27.3% of patients demonstrated Scan(-) Tg(-); in the intermediate group, the figures were 2.3% and 90.0% while in the low risk group, they were 0.6% and 96.4%. In 9 of 11 patients with metastases (81.8%), stimulated serum Tg level at the time of radioiodine ablation therapy was over 10, however in 1 patient (9.1%) it was

Information about the consequences of human exposure to radiation in the former Soviet Union has recently become available. These data add new insights and provide possible answers to several important questions regarding radiation and its impact on occupational and public health. The 1986 Chernobyl accident initiated a major and early increase in childhood thyroid cancer that resulted from ingestion of iodine-131 (131I) by young children living in the most heavily contaminated areas of Belarus, Ukraine, and Russia. No significant additional cancer or other adverse medical effects have yet been reported in the affected populations and among clean-up workers. Major psychological stress independent of radiation dose has been observed in those people thought to be exposed. During the early days of the atomic energy program in the former Soviet Union, some unfortunate events occurred. The country's first atomic test in Semipalatinsk in 1949 exposed over 25,000 people downwind from the blast to significant doses of fission products, especially 131I. During the late 1940s and the early 1950s nuclear material production facilities were developed near Chelyabinsk in the South Ural Mountains, which resulted in major releases into the environment and significant overexposures for thousands of workers and nearby populations. Chronic radiation sickness was observed early in exposed workers, and increases in leukemia and other cancers were also reported. The series of plutonium inhalation-related lung cancers and fatalities among workers exposed in that first decade appears to be unique. Long-term consequences of chronic radiation sickness and four decades of follow-up are being described for the first time. Villagers downstream from the plant consumed high levels of 137Cs and 90Sr and, it is reported, manifested increases in leukemia from internal and external exposures. Although the 40-year databases for retrospective dosimetry epidemiology studies are just beginning to be integrated and evaluated, preliminary evaluations suggest that there may be graded, significant dose-rate amelioration factors for cancer and leukemia risks in workers and the general population relative to the risk data on the Japanese atomic bomb survivors. Even for plutonium-induced lung cancers in workers, such a dose-rate effect may be evident. These experiences give us insight into the consequences of protracted radiation at high and low doses and rates. If these findings are validated and confirmed, they can provide information that reduces some of the uncertainties in retrospective radiation dosimetry and radiation risk estimates (especially for low-level, chronic exposures) for activities related to medicine as well as the handling of nuclear materials and nuclear facility decommissioning, decontamination, and demilitarization.

WOS: 000329627200006, PubMed ID: 24234516, Radioiodine is the most effective treatment modality in differentiated thyroid carcinoma, either in metastatic or residual thyroid tissue. However, sometimes dedifferentiation can develop and the effectiveness of radioactive I-131 decreases. The p53 is a tumor suppressor gene which plays an important role in controlling normal cell proliferation regulation. In the serum of healthy individuals, the presence of p53 autoantibodies is extremely rare. Mutations in this gene cause an accumulation of non-functional proteins and may lead to development of anti-p53 antibodies. The aim of the present study was to devise a simple blood test that could lead to early identification of patients with dedifferentiation. In this respect, we investigate whether the serum level of anti-p53 antibody is of diagnostic value in the follow-up of patients with high levels of thyroglobulin (Tg) and negative I-131 scan. Patients who were diagnosed with thyroid cancer, treated with total or near total thyroidectomy and referred for I-131 therapy or low dose I-131 whole body scan were included in our study. Blood samples were taken before the administration of I-131 orally in the group of patients. Besides, 28 healthy subjects were included. We quantified the presence of p53 autoantibodies from serums. In the present study were enrolled 171 patients with a mean age of 47.7 +/- A 13.5 years (range 16-80 years) and 28 healthy subjects with an age range of 18-52 years (mean 36.0 +/- A 9.8 years). One hundred and forty-eight patients had papillary (86.5 %), 7 (4.1 %) follicular, 10 (5.8 %) thyroid tumors of uncertain malignant potential, 2 (1.2 %) Hurthle cell carcinoma, 3 (1.8 %) poor differentiated, and 1 (0.6 %) undifferentiated thyroid carcinoma. The p53 antibodies were positive in 16 (9.4 %) patients and negative in 155 (90.6 %). The p53 antibodies were positive in 3 (10.7 %) healthy subjects, and negative in 25 (89.3 %) healthy subjects. In five patients with high Tg level and negative radioiodine scan, who were accepted as dedifferentiated, p53 antibodies were also negative. The results of the present study suggested that the level of serum p53 antibody seems to be of limited value in the demonstration of dedifferentiation in thyroid cancer patients., Cumhuriyet University Scientific Research Project Unit [T-485], The work was supported by grants from Cumhuriyet University Scientific Research Project Unit (T-485).

After the accident in Fukushima reactors, a daily monitoring programme was initiated in two laboratories in Belgrade, one at the VinD degrees Institute for Nuclear Sciences and the other at Institute for Occupational Health Karajovic. Samples of aerosol and fallout, as well as the random samples of food and water, were collected and analysed, using gross alpha/beta and gamma spectrometry, in order to establish the presence of traces of isotopes indicating Fukushima fallout. Gamma spectrometry measurement of these samples showed clear evidence of fission products I-131, Cs-134 and Cs-137 wtihin 2 weeks after the accident. The activity diminished with time due to dispersion in air and, in case of I-131, short half-life.

After undergoing radionuclide therapy, patients generate wastewater with a considerable amount of radioactivity, which can reach levels of as much as 90% of the administered dose. Due to the risk of accumulation after discharge into the sewer, it is advisable to collect this effluent for its treatment prior to final discharge. Delay and decay (natural decomposition of the isotope) is the most commonly used technical method of abating radioactive iodine, but it is frequently criticized as being complex and very expensive. BioChroma is a technology that has been developed as an alternative to these complicated and expensive systems. This paper describes this new technology and presents, as an example, a system that was installed and successfully commissioned in the middle of 2008 in a nuclear medicine ward with 12 beds in Stuttgart (Germany). Based on existing legislation, the responsible authorities and the company that operated the hospital agreed on a maximum activity level of 5 Bq/l. If a typical delay and decay system would have been installed, the 180 m³ treatment plant that was already available in the hospital cellar would have to be extended by additional 150 m³. By implementing the patented BioChroma process, the space requirements were reduced by 75%. For instance, since the new system was integrated into the existing installation, tanks accounting for 120 m³ could be used as buffering volume in the new wastewater treatment plant. The operation of the referred plant is currently producing very good results with values below the specified limit of 5 Bq/l for the isotope 131 I. In addition, 90 Y has been reported to be eliminated at the same time. Over the past 2 years of operation, the wastewater treatment plant has been able to achieve a maximum processing capacity of more than 2,000 l/day, which equates to a nuclear medicine ward with approx. 20 beds. The highest level recorded during the test period (of 180 days after start-up) was a peak of nearly 2,800 l/day.

Aim: To investigate the prognostic role of Tc-99m pertechnetate thyroid scintigraphy pretreatment in patients with toxic multinodular goiters (TMNG) who were then treated with fixed I-131 doses. Materials and methods: We retrospectively evaluated 28 patients (18 females and 10 males; mean ± SD = 63 ± 11 years) that were treated with 740 megabecquerels (MBq) of I-131 for TMNG. Information, including age, Tc-99m pertechnetate thyroid scintigraphy and ultrasonography findings, antithyroid medication, thyroid hormone profile, and clinical status before treatment, was recorded. Th e regions of interest were drawn over the hot nodules, salivary glands, and the background on the anterior thyroid images. Th e net nodule counts, net salivary counts, nodule-to-salivary ratios, and nodule-to-background ratios were then calculated. The data were statistically compared for the hypothyroid and euthyroid patient groups after radioiodine treatment. Results: In the study group, the mean follow-up period was 7 ± 2 months (range: 6-12 months). We detected hyperthyroidism in 1 patient, euthyroidism in 19 patients, and hypothyroidism in 8 patients. Th e pretreatment mean net nodule counts (34.79 ± 14.06 counts) in the patients that developed hypothyroidism were significantly higher than in those patients that developed euthyroidism (26.80 ± 11.04 counts) (P = 0.014). The other 3 parameters did not show significant differences between the 2 groups. Conclusion: Th e Tc-99m pertechnetate uptake level of hot nodules calculated from the pretreatment of thyroid scintigraphy in patients with TMNG treated with a fixed 740-MBq I-131 dose may predict early hypothyroidism in patients. © TÜBİTAK.

Whole-body (WB) planar imaging has long been one of the staple methods of dosimetry, and its quantification has been formalized by the MIRD Committee in pamphlet no 16. One of the issues not specifically addressed in the formalism occurs when the count rates reaching the detector are sufficiently high to result in camera count saturation. Camera dead-time effects have been extensively studied, but all of the developed correction methods assume static acquisitions. However, during WB planar (sweep) imaging, a variable amount of imaged activity exists in the detector's field of view as a function of time and therefore the camera saturation is time dependent. A new time-dependent algorithm was developed to correct for dead-time effects during WB planar acquisitions that accounts for relative motion between detector heads and imaged object. Static camera dead-time parameters were acquired by imaging decaying activity in a phantom and obtaining a saturation curve. Using these parameters, an iterative algorithm akin to Newton's method was developed, which takes into account the variable count rate seen by the detector as a function of time. The algorithm was tested on simulated data as well as on a whole-body scan of high activity Samarium-153 in an ellipsoid phantom. A complete set of parameters from unsaturated phantom data necessary for count rate to activity conversion was also obtained, including build-up and attenuation coefficients, in order to convert corrected count rate values to activity. The algorithm proved successful in accounting for motion- and time-dependent saturation effects in both the simulated and measured data and converged to any desired degree of precision. The clearance half-life calculated from the ellipsoid phantom data was calculated to be 45.1 h after dead-time correction and 51.4 h with no correction; the physical decay half-life of Samarium-153 is 46.3 h. Accurate WB planar dosimetry of high activities relies on successfully compensating for camera saturation which takes into account the variable activity in the field of view, i.e. time-dependent dead-time effects. The algorithm presented here accomplishes this task.

Iodine-131 concentrations were measured throughout the summer of 1986 in thyroids of lambs slaughtered at Ioannina (Northwestern Greece) following the accident at the Chernobyl nuclear reactor. During the survey, 40 thyroids were collected. The highest level of I-131 detected was 2471 +/- 339 Bq per thyroid. The thyroids of 20 lambs did not contain detectable I-131 concentrations, while the contamination content of the others was greatly variable. The transport of I-131 from pasture to thyroids of lambs has been described through a simple model for the retention of I-131 in the glands. The transfer coefficient f(T), expressing the steady-state equilibrium, was estimated to be 564 +/- 270 kg-1 d. This result reflects the sensitivity of animal thyroids as biological radioiodine monitors. Health Phys

Radionuclide scintigraphy with I-131 and Tc-99m pertechnetate ((99)mTc04) has been widely used in detecting toxic nodules. Intrathoracic goiter usually presents as an anterior mediastinal mass. Mostly the connection between intrathoracic mass and the cervical thyroid gland is clearly and easily identified occurring as a result of inferior extension of thyroid tissue in the neck, which is called as secondary intrathoracic goiter. Completely separated, aberrant or in other words primary intrathoracic goiters arise as a result of abnormal embryologic migration of ectopic thyroid closely associated with aortic sac and descend into the mediastinum. Intrathoracic goiters are generally nontoxic nodules existing with mass effect without causing hyperthyroidism. However, mostly reported cases had enlarged thyroid glands in the neck. This report demonstrates the usefulness of I-131 and (99)mTc04 scintigraphy for detecting intrathoracic goiter causing hyperthyroidism with a normal functioned cervical thyroid gland.

WOS: 000235852700021, PubMed ID: 16462075, The aim of the present study was to label acetaminophen (APAP) with I-131 and to determine its radiopharmaceutical potential in rats. Acetaminophen was labeled with I-131 using the iodogen method. The radiochemical purity of I-131-APAP was determined by RTLC and paper electrophoresis. The labeling yield was 94 +/- 4%. The biodistribution studies of the labeled compound (specific activity; 56.60 GBq/mmol) were performed in male Albino Wistar rats. The uptake of I-131-APAP in some organs were determined at different time after injection to the rats. The radioactivity in each organ was counted and the percentage of injected activity per gram of tissue weight (%ID/g) for each organ and blood was calculated. I-131-APAP uptake in the lung, liver, kidneys, pancreas, blood, stomach and some brain region, were observed. Thus, I-131-APAP may be radiopharmaceutical for the imaging of the brain.

1.- DELIMITACIÓN DE OBJETIVOS E HIPÓTESIS DE TRABAJO: I. Evaluar la eficacia y factores pronósticos del tratamiento con I131 a dosis bajas calculadas del hipertirodismo por enfermedad de Graves: Incidencia de hipotiroidismo permanente a corto y largo plazo, tasa de recidiva, hipotiroidismo transitorio (definición, incidencia y factores pronósticos) y sus factores pronósticos. Debería conseguir una incidencia baja de hipotiroidismo y de retratamiento que justifique el mayor coste económico, logístico y de seguimiento. La definición de factores pronósticos permitirá optimizar los criterios de indicación, el propio protocolo de tratamiento con I131, el seguimiento (diferenciar el retraso de respuesta del fracaso del I131 y evitar el tratamiento sustitutivo crónico en el hipotiroidismo transitorio) y establecer una nueva indicación terapéutica en la disminución del tamaño tiroideo (hasta la actualidad criterio de tratamiento quirúrgico). II. Definir la evolución de la función y volumen tiroideos de adenoma y bocio multinodular tóxicos tratados con I131. Debería conseguir una incidencia baja de hipotiroidismo y recidiva con una disminución significativa del tamaño tiroideo que permita ampliar sus indicaciones: como alternativa terapéutica de elección del adenoma y bocio multinodular tóxicos, incluso compresivos, y en bocios multinodulares no tóxicos.2.- ADECUACIÓN DEL MÉTODO A LOS OBJETIVOS PLANTEADOS:I. Para describir y analizar los factores pronósticos de la función tiroidea final tras el tratamiento con I131 del hipertiroidismo por enfermedad de Graves se realizó un estudio retrospectivo de 372 pacientes (variables: sexo, edad, tratamiento previo con antitiroideos y/o cirugía, función tiroidea previa, captaciones de I131 y desarrollo de hipotiroidismo transitorio) y otro prospectivo con 50 pacientes consecutivos (variables: patrón hormonal, inmunológico y volumen tiroideo).II. Para describir y analizar los factores pronósticos de la evolución de la función y volumen tiroideos se realizó un estudio prospectivo de 15 pacientes con adenoma tóxico tratados con dosis fijas y otros 15 pacientes consecutivos con bocio multinodular tóxico tratados con dosis calculadas de I131.3.- JUICIO PONDERADO DE LAS APORTACIONES DE LA TESIS:I. Los resultados obligan a evaluar el coste-efectividad del tratamiento con I131 a dosis bajas calculadas del hipertiroidismo por enfermedad de Graves, porque se demuestra una incidencia alta de hipotiroidismo (probabilidad a los 12 años de seguimiento del 90%, mediana de 2 años) y de tasa de retratamiento (del 26 al 30%). Los factores pronósticos identificados son poco precisos (concentraciones de T4 total pretratamiento >300 nmol/l confieren un riesgo mayor de fallo del tratamiento y concentraciones de T3 pretratamiento >9 nmol/l de desarrollar hipotiroidismo permanente). Sin embargo, el cálculo del volumen tiroideo ecográfico permite optimizar el tratamiento con I131:a. Evitar el fallo del I131 incrementando la dosis de I131 si el volumen tiroideo basal fuera superior a 45 ml, porque es pronóstico de persistencia del hipertiroidismo.b. Evitar el retraso del control del hipertiroidismo por la diversidad de patrones de función tiroidea durante los 6 meses posteriores al I131 que no reflejan la función tiroidea final, indicando el retratamiento cuando el volumen tiroideo al tercer mes del I131 fuera superior a 24,4 ml, porque es pronóstico de persistencia del hipertiroidismo.c. La presencia de hipotiroidismo durante los 6 meses posteriores al I131 y volumen tiroideo inferior a 8,5 ml al tercer mes y/o a 9,3 ml al sexto mes es pronóstico de hipotiroidismo permanente.d. El desarrollo de hipotiroidismo transitorio (10-12%) no es pronóstico de la función tiroidea final, pero su identificación (TSH >45 mU/L lo descartan) evita el tratamiento sustitutivo innecesario.e. El tratamiento con I131 produce una reducción media del 50% del tamaño tiroideo, por tanto es una alternativa al tratamiento quirúrgico por motivos estéticos. No obstante, la medición del volumen tiroideo ecográfico antes del tratamiento con I131 para el cálculo de la dosis de I131 y posteriormente como factor pronóstico de la función tiroidea final encarece el coste y complica la logística de este método de tratamiento con I131 justificando un cambio de protocolo a dosis bajas fijas.II. El tratamiento con I131 de los nódulos tóxicos consigue una restauración rápida del eutiroidismo (>90% para el adenoma tóxico y >80% para el bocio multinodular, al tercer mes), con una incidencia baja de hipotiroidismo (0% para el adenoma tóxico y 20% para el bocio multinodular tóxico a los 2 años) obviando las complicaciones del tratamiento quirúrgico. La reducción del volumen tiroideo es superior al 50% para el adenoma tóxico y del 40% para el bocio multinodular tóxico durante los 6 meses posteriores al I131. No se han identificado factores pronósticos de la evolución de la función ni de la reducción del volumen tiroideos.Dada la eficacia de este tipo de tratamiento, se confirma como la alternativa terapéutica de elección al tratamiento quirúrgico del adenoma y bocio multinodular tóxicos, incluso con bocio voluminoso, o si fuera necesaria una restauración rápida del eutiroidismo (durante los primeros 3 meses).

金沢大学附属病院核医学診療科, A 61-year-old woman after total thyroidectomy for papillary thyroid cancer underwent I-131 therapy. Focal uptake was seen in the chest on whole body imaging. SPECT/CT delineated I-131 accumulation in an isodense mediastinal lesion which was histologically diagnosed as a thymic cyst. I-131 uptake in a thymic cyst is rare and should be included in the gamut of false-positive entities of I-131 scintigraphy. Copyright © 2010 by Lippincott Williams & Wilkins.

We present a patient with thyroid cancer and hypopituitarism who required recombinant human thyrotropin (rhTSH) for I-131 Scanning with respect to subsequent therapy. The thyroid cancer had been unknown until central neurological symptoms developed, leading to the diagnosis of a huge metastasis to the sella that was the only manifestation of metastatic spread. The failure to generate endogenous thyrotropin (TSH) was overcome by the use of rhTSH for performing a I-131 test. Unfortunately, the I-131 uptake was not sufficient for therapy. This subject is the first reported case who required the application of rhTSH due to a single thyroid cancer metastasis in the sella region with secondary failure to generate endogenous TSH.

To evaluate the usefulness of submitting children with thyroid cancer secondary to nuclear accidents to a completion total thyroidectomy.A case series consisting of patients living and operated on in Belarus whose parents had asked for a clinical evaluation in a western European center.A tertiary care referral center.The conditions of 47 children from Gomel, Belarus, with differentiated thyroid carcinoma following the nuclear accident at Chernobyl, Ukraine, were evaluated at the University of Pisa, Pisa, Italy. In approximately half of the cases, the treatment in Belarus consisted of a hemithyroidectomy. After a complete evaluation, the decision was made to reoperate on 19 of them by performing a completion total thyroidectomy. The preoperative evaluation revealed that 5 (26%) of the 19 patients who had undergone a hemithyroidectomy had unilateral recurrent nerve palsy and that 2 (10.5%) had hypoparathyroidism.Neck ultrasonography was used for the preoperative localization of thyroid residuals, thyroid nodules, suspicious lymph nodes, and a guided fine-needle aspiration biopsy specimen. The circulating thyroglobulin measurement was obtained before reoperation. An iodine 131 whole-body scan (WBS) was performed and circulating thyroglobulin levels were obtained after completion of the thyroidectomy during withdrawal of levothyroxine sodium therapy.The number of patients with a recurrence of thyroid cancer and lung or lymph node metastases after the completion total thyroidectomy.The results of the histologic examination were positive for papillary thyroid cancer in 6 (28.6%) of 21 patients, 3 with residual cancer in the remaining thyroid lobe and 3 with metastatic lymph node disease. A posttherapy WBS demonstrated lung metastases in 5 (28%) of 18 patients and lymph node metastases in 6 (33%) of 18 patients; the results of a posttherapy WBS were negative for metastases in 7 (39%) of 18 patients. Hypoparathyroidism developed in 4 (21%) of 19 patients who underwent a completion total thyroidectomy; unilateral laryngeal nerve palsy developed in 1 (5.2%) of these 19 patients. Among 22 children who previously underwent total thyroidectomy in Belarus, a diagnostic WBS showed lung metastases in 10 (45%) of the children and lymph node metastases alone in 3 (14%) of the children; the results of a diagnostic WBS were negative for metastases in 9 (41%) of the children. Statistical analysis showed a nonsignificant (P.05) difference in the prevalence of lung and lymph node metastases in patients who previously underwent total thyroidectomy compared with patients who underwent completion total thyroidectomy.Completion total thyroidectomy allowed for the diagnosis and treatment of recurrent thyroid cancer and lung or lymph node metastases in 61% (11/18) of the patients in whom residual differentiated thyroid carcinoma was not previously recognized.

In the second part of this review article, the diagnostic aspects of thyroid scintigraphy are discussed, with major emphasis on hyperthyroidism, followed by an overview of radioiodine treatment.

Background One of the most efficient radiation protection methods to reduce the risk of adverse health outcomes in case of accidental radioactive iodine release is the administration of potassium iodine (KI). Although KI administration is recommended by WHO’s guidelines for iodine prophylaxis following nuclear accidents and is also widely implemented in most national guidelines, the scientific evidence for the guidelines lacks as the guidelines are mostly based on expert opinions and recommendations. Therefore, this study will provide evidence by systematically reviewing the effects of KI administration in case of accidental radioactive iodine release on thyroid cancer, hypothyroidism, and benign nodules. Methods We will apply standard systematic review methodology for the identification of eligible studies, data extraction, assessment of risk of biases, heterogeneity, and data synthesis. The electronic database search will be conducted in MEDLINE (via PubMed) and EMBASE, and covers three search blocks with terms related to the health condition, intervention, and occurrence/location. We have no date or language restrictions, but restrictions to humans only. We will include studies comparing the effects of KI administration on thyroid cancer, hypothyroidism, and benign thyroid nodules in a population exposed to radioactive iodine release. The quality of the studies will be graded. If feasible, a meta-analysis will be conducted. Discussion This proposed systematic review will update the existing WHO guideline from 1999. New evidence on the efficacy of KI administration to reduce thyroid cancer, hypothyroidism, and benign thyroid nodules in the event of an accidental release of radioactive iodine to the environment will provide the basis for an update of the WHO guideline for iodine prophylaxis following nuclear accidents. Systematic review registration PROSPERO CRD42015024340 Electronic supplementary material The online version of this article (doi:10.1186/s13643-015-0106-3) contains supplementary material, which is available to authorized users.