High-dose radiation exposure and hypothyroidism: aetiology, prevention and replacement therapy.

Without any doubt, high dose radiation exposure can induce hypothyroidism. However, there are open questions related to the mechanisms of its induction, corresponding dose thresholds and possible countermeasures. Therefore, this review addresses the aetiology, prevention and therapy of radiation induced hypothyroidism. External beam radiotherapy with several 10 Gy to the head and neck region and radioiodine therapy with several 100 Gy thyroid absorbed dose can destroy the thyroid gland and can induce autoantibodies against thyroid tissue. According to recent literature, clinical hypothyroidism is observed at threshold doses of ∼10 Gy after external beam radiotherapy and of ∼50 Gy after radioiodine therapy, children being more sensitive than adults. In children and adolescents exposed by the Chernobyl accident with mean thyroid absorbed doses of 500-800 mGy, subclinical hypothyroidism has been detected in 3%-6% of the cases with significant correlation to thyroid absorbed doses above 2.5 Gy. In case of nuclear emergencies, iodine thyroid blocking (ITB) is the method of choice to keep thyroid absorbed doses low. Large doses of stable iodine affect two different steps of internalization of radioiodine (transport and organification); perchlorate affecting the transport only may be an alternative to iodine. Administered before radioiodine incorporation, the effect of 100 mg iodide or more is still about 90% after 1 days, 80% after 2 days, and 50% or less after 3 days. If administered (too) late after exposure to radioiodine, the theoretically expected protective effect of ITB is about 50% after 6 h, 25% after 12 h, and about 6% after 24 h. In case of repeated or continuous exposure, repeated administration of 50 mg of iodide daily is indicated. If radiation-induced hypothyroidism cannot be avoided, thyroid hormone replacement therapy with individualized dosing and regular monitoring in order to maintain thyroid-stimulating hormone levels within the normal range ensures normal life expectancy.

Supporting effective participation in health guideline development groups: The Guideline Participant Tool.

OBJECTIVES: Health guidelines are a key knowledge translation tool produced and used by numerous stakeholders worldwide. Effective participation in guideline development groups or development groups is crucial for guideline success, yet little guidance exists for members of these groups. In this study, we present the Guideline Participant Tool (GPT) to support effective participation in guideline groups, in particular those using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. STUDY DESIGN AND SETTING: We used a mixed methods and iterative approach to develop a tool to support guideline participation. We used the findings of a published systematic review to develop an initial list of items for considerations for guideline participants. Then, we refined this list through key informant interviews with guideline chairs, sponsors, and participants. Finally, we validated the GPT in three guideline groups with 26 guideline group members. RESULTS: The initial list of items based on 37 articles from the existing systematic review included 15 themes and 61 items for a draft tool. Ten key informant interviews helped us refine the list to include the following themes: selection of participants, guideline group process, and tool format. 26 respondents completed the validation survey from three guideline groups. Refinement of the tool ultimately generated a GPT with 33 items for participant consideration before, during, and in follow-up to guideline group meetings. CONCLUSION: The GPT contains helpful guidance for all guideline participants, particularly those without previous guideline experience. Future research should further explore the need for additional tools to support guideline participants and identify and develop strategies for improving guideline members' participation in guideline groups. This work will be incorporated into INGUIDE.org guideline training and credentialing efforts by the Guidelines International Network and McMaster University.

Feasibility Study Shows Multicenter, Observational Case-Control Study Is Practicable to Determine Risk of Secondary Breast Cancer in Females With Differentiated Thyroid Carcinoma Given Radioiodine Therapy in Their Childhood or Adolescence; Findings Also Suggest Possible Fertility Impairment in Such Patients.

Objective: This single-center, observational case-control feasibility study sought to test key elements of a protocol for an eventual long-term international observational case-control study of a larger patient cohort, to evaluate the risk of breast cancer as a second primary malignancy in females with differentiated thyroid cancer (DTC) given radioiodine therapy (RAI) during childhood or adolescence. Patients: Females developing DTC after the Chernobyl accident in Belarus and ≤19 years old at the time of thyroid surgery were enrolled: patients given RAI (n = 111) and controls of similar age not given RAI (n = 90). Results: One case of breast cancer was newly diagnosed among the RAI patients, but none in controls. Patients given RAI significantly less frequently needed 2nd surgeries than did controls (23%, 26/111 vs. 39%, 35/90, P < 0.05); the main indication for such procedures usually is suspicion of local recurrence. RAI patients appeared to have had more frequent reproductive difficulties than did controls: 78% (87/111) of the former vs. 93% (84/90) of the latter had a history of pregnancy (P < 0.01), and the mean number of pregnancies was 1.5 ± 1.2 in RAI patients vs. 1.9±1.1 in controls (P < 0.05). Most notably, infertility was observed in 23% (26/111) of RAI patients vs. 4% (4/90) of controls (P < 0.01). In conclusion, a international observational case-control study on breast cancer after DTC in patients given RAI vs. not given RAI appears to be feasible. Additional research and everyday clinical attention should be devoted to reproductive function after RAI in young females.

Breast Cancer After Treatment of Differentiated Thyroid Cancer With Radioiodine in Young Females: What We Know and How to Investigate Open Questions. Review of the Literature and Results of a Multi-Registry Survey.

Published studies on the risk of radiation-induced second primary malignancy (SPM) after radioiodine treatment (RAI) of differentiated thyroid cancer (DTC) refer mainly to patients treated as middle-aged or older adults and are not easily generalizable to those treated at a younger age. Here we review available literature on the risk of breast cancer as an SPM after RAI of DTC with a focus on females undergoing such treatment in childhood, adolescence, or young adulthood. Additionally, we report the results of a preliminary international survey of patient registries from academic tertiary referral centers specializing in pediatric DTC. The survey sought to evaluate the availability of sufficient patient data for a potential international multicenter observational case-control study of females with DTC given RAI at an early age. Our literature review identified a bi-directional association of DTC and breast cancer. The general breast cancer risk in adult DTC survivors is low, ~2%, slightly higher in females than in males, but presumably lower, not higher, in those diagnosed as children or adolescents than in those diagnosed at older ages. RAI presumably does not substantially influence breast cancer risk after DTC. However, data from patients given RAI at young ages are sparse and insufficient to make definitive conclusions regarding age dependence of the risk of breast cancer as a SPM after RAI of DTC. The preliminary analysis of data from 10 thyroid cancer registries worldwide, including altogether 6,449 patients given RAI for DTC and 1,116 controls, i.e., patients not given RAI, did not show a significant increase of breast cancer incidence after RAI. However, the numbers of cases and controls were insufficient to draw statistically reliable conclusions, and the proportion of those receiving RAI at the earliest ages was too low.In conclusion, a potential international multicenter study of female patients undergoing RAI of DTC as children, adolescents, or young adults, with a sufficient sample size, is feasible. However, breast cancer screening of a larger cohort of DTC patients is not unproblematic for ethical reasons, due to the likely, at most slightly, increased risk of breast cancer post-RAI and the expected ~10% false-positivity rate which potentially produced substantial "misdiagnosis."

The First Meeting of the WHO Guideline Development Group for the Revision of the WHO 1999 Guidelines for Iodine Thyroid Blocking.

The meeting held in May 2014 in Würzburg, Germany, discussed the scope of the revision of the 1999 WHO guidelines for iodine thyroid blocking (ITB) by following the WHO handbook for guideline development. This article describes the process and methods of developing the revised, evidence-based WHO guidelines for ITB following nuclear and radiological accidents, the results of the kick-off meeting as well as further steps taken to complete the revision.

[In-hospitaltraumamanagement - radiation emergency and multiple trauma - principals of treatment in the emergency room]. / Innerklinisches Traumamanagement - Schockraumversorgung von Patienten nach Strahlenunfällen.

Exposure to ionizing radiation combined with multiple trauma is a very rare but severe event. There are some important basic principles for the early inpatient management. An externally exposed patient poses no risk to the treatment team. Injuries require treatment in order of priority as known for example by ATLS(®). Against external contamination, the treatment team is adequately protected by wearing protective clothing and gloves in conformity with universal medical precautions. Treatment of life threatening injuries takes priority over decontamination. Specialized treatment centres should be involved early on in patient treatment.

Potassium iodide (KI) to block the thyroid from exposure to I-131: current questions and answers to be discussed.

Thyroid cancer in children and adolescents has to be considered as the most severe health consequence of a nuclear reactor emergency with release of radioiodine into the atmosphere. High doses of potassium iodide are effective to block radioiodine thyroid uptake and to prevent development of thyroid cancer years later. However, there are controversies concerning thyroid cancer risk induced by radioiodine exposure in adults. Further, the interaction of nutritional supply of potassium iodide and radioiodine uptake as well as the interaction of radioiodine with certain drugs has not been addressed properly in existing guidelines and recommendations. How to proceed in case of repeated release of radioiodine is an open, very important question which came up again recently during the Fukushima accident. Lastly, the side effects of iodine thyroid blocking and alternatives of this procedure have not been addressed systematically up to now in guidelines and recommendations. These questions can be answered as follows: in adults, the risk to develop thyroid cancer is negligible. In countries, where nutritional iodine deficiency is still an issue, the risk to develop thyroid cancer after a nuclear reactor emergency has to be considered higher because the thyroid takes up more radioiodine as in the replete condition. Similarly, in patients suffering from thyrotoxicosis, hypothyroidism or endemic goitre not being adequately treated radioiodine uptake is higher than in healthy people. In case of repeated or continued radioiodine release, more than one dose of potassium iodide may be necessary and be taken up to 1 week. Repeated iodine thyroid blocking obviously is not harmful. Side effects of iodine thyroid blocking should not be overestimated; there is little evidence for adverse effects in adults. Newborns and babies, however, may be more sensitive to side effects. In the rare case of iodine hypersensitivity, potassium perchlorate may be applied as an alternative to iodine for thyroid blocking.

Effects of levothyroxine on bone mineral density, muscle force, and bone turnover markers: a cohort study.

CONTEXT: Previous studies of the effects of levothyroxine (LT(4)) therapy on bone and bone metabolism have provided conflicting results. OBJECTIVE: This study evaluated the potential effects and dose-response relationship of LT(4) therapy on bone mineral density (BMD) as well as bone and muscle strength. DESIGN AND SETTING: We conducted a prospective, nonrandomized, controlled cohort study with 1.1 ± 0.2-yr follow-up at an academic outpatient clinic in Germany. PARTICIPANTS: Ninety-seven men and premenopausal women were enrolled in the study after thyroidectomy and radioiodine remnant ablation for well-differentiated thyroid carcinoma (DTC) or strumectomy for nontoxic goiter. Patients were matched with 89 healthy controls. INTERVENTIONS: Twenty-eight men and 46 women on TSH-suppressive doses of LT(4) had DTC, and 23 women were on LT(4) replacement therapy for nontoxic goiter. MAIN OUTCOME MEASURE: This study assessed total and trabecular volumetric BMD (vBMD) as well as bone strength at the ultradistal radius, areal BMD at the lumbar spine and both hips, and the grip strength of the nondominant forearm. The dependent variables were annualized rates of change. RESULTS: LT(4) therapy did not impair the areal BMD, bone strength, or grip strength of patients compared with controls. Women with DTC showed a significant loss of total vBMD, whereas men with DTC developed marginally less bone strength than women. Carboxy-terminal telopeptide indicated greater bone resorption in DTC patients compared with controls. CONCLUSIONS: There was little evidence of adverse LT(4) effects on bone; however, premenopausal women with DTC might be at risk for reduced vBMD in their ultradistal radii.

First global consensus for evidence-based management of the hematopoietic syndrome resulting from exposure to ionizing radiation.

OBJECTIVE: Hematopoietic syndrome (HS) is a clinical diagnosis assigned to people who present with ≥ 1 new-onset cytopenias in the setting of acute radiation exposure. The World Health Organization convened a panel of experts to evaluate the evidence and develop recommendations for medical countermeasures for the management of HS in a hypothetical scenario involving the hospitalization of 100 to 200 individuals exposed to radiation. The objective of this consultancy was to develop recommendations for treatment of the HS based upon the quality of evidence. METHODS: English-language articles were identified in MEDLINE and PubMed. Reference lists of retrieved articles were distributed to panel members before the meeting and updated during the meeting. Published case series and case reports of individuals with HS, published randomized controlled trials of relevant interventions used to treat nonirradiated individuals, reports of studies in irradiated animals, and prior recommendations of subject matter experts were selected. Studies were extracted using the Grading of Recommendations Assessment Development and Evaluation (GRADE) system. In cases in which data were limited or incomplete, a narrative review of the observations was made. No randomized controlled trials of medical countermeasures have been completed for individuals with radiation-associated HS. The use of GRADE analysis of countermeasures for injury to hematopoietic tissue was restricted by the lack of comparator groups in humans. Reliance on data generated in nonirradiated humans and experimental animals was necessary. RESULTS: Based upon GRADE analysis and narrative review, a strong recommendation was made for the administration of granulocyte colony-stimulating factor or granulocyte macrophage colony-stimulating factor and a weak recommendation was made for the use of erythropoiesis-stimulating agents or hematopoietic stem cell transplantation. CONCLUSIONS: Assessment of therapeutic interventions for HS in humans exposed to nontherapeutic radiation is difficult because of the limits of the evidence.

Literature review and global consensus on management of acute radiation syndrome affecting nonhematopoietic organ systems.

OBJECTIVES: The World Health Organization convened a panel of experts to rank the evidence for medical countermeasures for management of acute radiation syndrome (ARS) in a hypothetical scenario involving the hospitalization of 100 to 200 victims. The goal of this panel was to achieve consensus on optimal management of ARS affecting nonhematopoietic organ systems based upon evidence in the published literature. METHODS: English-language articles were identified in MEDLINE and PubMed. Reference lists of retrieved articles were distributed to conferees in advance of and updated during the meeting. Published case series and case reports of ARS, publications of randomized controlled trials of relevant interventions used to treat nonirradiated individuals, reports of studies in irradiated animals, and prior recommendations of subject matter experts were selected. Studies were extracted using the Grading of Recommendations Assessment Development and Evaluation system. In cases in which data were limited or incomplete, a narrative review of the observations was made. RESULTS: No randomized controlled trials of medical countermeasures have been completed for individuals with ARS. Reports of countermeasures were often incompletely described, making it necessary to rely on data generated in nonirradiated humans and in experimental animals. A strong recommendation is made for the administration of a serotonin-receptor antagonist prophylactically when the suspected exposure is >2 Gy and topical steroids, antibiotics, and antihistamines for radiation burns, ulcers, or blisters; excision and grafting of radiation ulcers or necrosis with intractable pain; provision of supportive care to individuals with neurovascular syndrome; and administration of electrolyte replacement therapy and sedatives to individuals with significant burns, hypovolemia, and/or shock. A strong recommendation is made against the use of systemic steroids in the absence of a specific indication. A weak recommendation is made for the use of fluoroquinolones, bowel decontamination, loperamide, and enteral nutrition, and for selective oropharyngeal/digestive decontamination, blood glucose maintenance, and stress ulcer prophylaxis in critically ill patients. CONCLUSIONS: High-quality studies of therapeutic interventions in humans exposed to nontherapeutic radiation are not available, and because of ethical concerns regarding the conduct of controlled studies in humans, such studies are unlikely to emerge in the near future.

German hospital database-allocation of patients to appropriate hospitals.

Effective response to radiological emergencies requires information about available qualified hospitals and defined methods to timely allocate patients to appropriate hospitals. In Germany, updated information about hospitals concerning their qualification and willingness to treat radiological emergency patients is not summarized. The objectives were to identify qualified hospitals, assess hospital capacities and treatment capabilities, to examine willingness to respond to various radiological emergencies and to develop a concept for matching patients to hospitals. A Germany-wide combined postal/Web survey of 99 selected hospitals conducted in 2007 covered relevant organizational characteristics, hospital resources, treatment expertise, and the willingness to accept radiological emergency patients by a self-reported written questionnaire with 57 items. Survey results were documented in a Microsoft Access database. A database-driven Web application was developed to allocate patients to hospitals. Of 99 hospitals, 69 responded and 54 indicated their willingness to accept radiological emergency patients. 17,512 total hospital beds, 2,084 intensive care, and 170 reverse isolation beds were reported. Availability of laboratory and in-patient departments ranged from 14 radiobiology to 47 laboratory medicine departments and from 13 burn care to 52 trauma surgery departments. 48 and 40 hospitals stated treatment competence for local and whole body external exposure, respectively. 34 and 29 hospitals reported treatment expertise for contamination and incorporation, respectively. In this publication baseline data of qualified hospitals concerning capacities and competence to manage radiological emergency patients are presented, and an allocation concept for radiological emergency patients is provided.