The Effects of 2100 MHz Radio Frequency Radiation on Thyroid Tissues

ABSTRACT Objective: To reveal the effect of 2100 MHz radio frequency (RF) radiation on thyroid tissues of rats in the 10 days (group E1) and 40 days (group G1) exposure groups. Methods: In this study, 30 healthy female Wistar albino rats, weighing 200−256 g each, were used. The animals were randomly divided into four groups (E1, E2, G1 and G2). Groups E2 and G2 served as the control groups. The exposure groups were exposed to 2100 MHz RF radiation emitted by a generator, simulating a 3G-mobile phone for 6 hours/day, 5 consecutive days/week, at the same time of the day (between 9 am and 3 pm), for 10 days (group E1) and 40 days (group G1). Results: Catalase and xanthine oxidase enzyme activities were compared between the groups E1 and E2; it was found that the difference was statistically significant (p < 0.05). Between the groups G1 and G2, the difference was found to be significant with respect to catalase activities. Tissue samples of the early and late groups showed no serious pathological findings in the histopathological examination. Conclusion: We believe that comprehensive, clinical and experimental studies are needed to assess the effect of the RF exposure duration and dosage of exposure on thyroid tissues.

Tejido tiroideo y láser infrarrojo: un estudio morfométrico / Thyroid tissue and infrared laser: a morphometric study

La glándula tiroides posee gran importancia debido a la síntesis y secreción de hormonas, las cuales desempeñan funciones fundamentales para la mantención de la fisiología animal. En este contexto, el objetivo del presente trabajo consistió en determinar parámetros morfométricos de estructuras tiroideas sometidas a estimulaciones con láser infrarrojo (LIR). Para ello, 10 ratas Sprague Dawley de 3 meses de vida y peso aproximado de 200 g, fueron divididas en dos grupos de 5 animales cada uno: grupo control y grupo experimental. Estos últimos recibieron estimulaciones infrarrojas en la tiroides con dosis de 16 J/cm2 durante 15 días seguidos. Una vez sacrificadas las ratas, se extrajeron las glándulas tiroides las que fueron procesadas para microscopía óptica obteniéndose placas histológicas y micrografías con aumentos finales de hasta 1000 X. Se efectuaron estudios morfométricos para determinar en 40 placas, variaciones tisulares generadas por las inducciones infrarrojas, con especial énfasis en la disposición coloidal y dimensiones de folículos y células tiroideas. El análisis de las 40 placas histológicas generados por las inducciones del láser infrarrojo comparados con los controles, reveló que existen marcadas diferencias en todos los componentes del tejido tiroideo analizado, lo cual podría otorgar antecedentes de diferentes funcionalidades en el metabolismo de las glándulas.

The thyroid gland is of great importance because of the synthesis and secretion of hormones which play key roles in the maintenance of animal physiology. In this context, the aim of the present study was to determine morphometric parameters of thyroid structures subjected to infrared laser stimulation (ILS) and for this purpose, 10 Sprague Dawley rats, 3 months of age and weighing approximately 200 grams, were divided into two groups of 5 animals each: the control group and the remaining 5 animals constituting the experimental group received infrared stimulation in the thyroid with doses of 16 J/cm2 for 15 consecutive days. After the rats were sacrificed, the respective thyroids were removed and processed for optical microscopy. Histological plates and micrographs were obtained with final increases of up to 1000 X. Morphometric studies were carried out to determine the tissue variations generated by infrared inductions, with special emphasis on the colloidal arrangement and dimensions of follicles and thyroid cells. Our results revealed that there are marked differences in all the components of the analyzed thyroid tissue which could give antecedents of different functionalities in the metabolism of thyroid glands.

Radiation exposure and thyroid cancer: a review

ABSTRACT The association between radiation exposure and the occurrence of thyroid cancer has been well documented, and the two main risk factors for the development of a thyroid cancer are the radiation dose delivered to the thyroid gland and the age at exposure. The risk increases after exposure to a mean dose of more than 0.05-0.1 Gy (50-100mGy). The risk is more important during childhood and decreases with increased age at exposure, being low in adults. After exposure, the minimum latency period before the appearance of thyroid cancers is 5 to 10 years. Papillary carcinoma (PTC) is the most frequent form of thyroid carcinoma diagnosed after radiation exposure, with a higher prevalence of the solid subtype in young children with a short latency period and of the classical subtype in cases with a longer latency period after exposure. Molecular alterations, including intra-chromosomal rearrangements, are frequently found. Among them, RET/PTC rearrangements are the most frequent. Current research is directed on the mechanism of genetic alterations induced by radiation and on a molecular signature that can identify the origin of thyroid carcinoma after a known or suspected exposure to radiation.

Efecto del láser infrarrojo sobre células tiroideas / Infrared laser effect on thyroid cells

Diez ratas Sprague Dawley de 4 meses de vida y peso aproximado de 250 g fueron divididas en dos grupos de 5 animales cada uno, el grupo A se mantuvo como control y los animales del grupo B recibieron estimulaciones con láser infrarrojo en la tiroides con dosis de 16 J/cm2 durante 15 días consecutivos. Posteriormente las ratas fueron sacrificadas, se extrajeron las respectivas tiroides siendo procesadas para microscopía óptica y se obtuvieron placas histológicas y micrografías de tiroides con aumentos finales de hasta 1000X, las cuales fueron sometidas a estudios morfométricos para determinar en 100 células foliculares: número, áreas y perímetro tanto celular como nuclear, además de disposición coloidal y presencia de vasos sanguíneos. El análisis de los resultados entre las 100 células foliculares pertenecientes a tiroides normal y estimulada revela que existen marcadas diferencias en todos los componentes analizados los que se podría traducir en distintas funcionalidades en el metabolismo de las respectivas glándulas.

Ten 4-month-old Sprague Dawley rats weighing approximately 250 g were divided into two groups of 5 animals each. Group A was the control and the animals in group B received thyroid stimulation with infrared laser in a dose of 16 J/cm2 for 15 consecutive days. Subsequently, rats were euthanized and thyroids were removed and processed for optical microscopy. From both cell types thyroid histological slides and micrographs were obtained with final increases of 400 and 1000X. Morphometric analysis determined the number, areas and cell perimeter as well as colloidal dispersion and presence of blood vessels in 100 follicular cells. Analysis of the results among the 100 follicular cells belonging to normal and stimulated thyroids revealed marked differences in all the analyzed components, which could translate into different functionalities in the metabolism of the respective glands.

Alterações tireoidianas associadas à radiação externa em crianças e adolescentes / Thyroid disorders associated with external radiation in children and adolescents

O efeito da radiação ionizante sobre a tireoide vem sendo estudado há várias décadas, e os acidentes nucleares têm sido a maior fonte de informação. Existe associação de hipotireoidismo, hipertireoidismo, nódulos e câncer de tireoide com a radiação, mas os limiares de dose, mecanismos de lesão e alguns fatores de risco ainda não estão bem estabelecidos. Crianças são mais suscetíveis à lesão tireoidiana por radiação e necessitam de seguimento prolongado após a exposição. Esse tema adquire maior relevância atualmente, pois um grande número de pessoas tratadas com radioterapia para câncer na infância sobrevive e poderá apresentar sequelas. Exames radiodiagnósticos também representam fonte de exposição à radiação na população pediátrica. Nesta revisão, analisamos as diferentes alterações clínico-patológicas e os mecanismos de lesões tireoidianas provocadas por tratamento radioterápico e tomografia computadorizada em crianças e adolescentes. É importante conhecer esses dados para prevenção, detecção precoce e tratamento da disfunção tireoidiana.

The effects of ionizing radiation on the thyroid have been studied for several decades, and nuclear accidents are the major source of information about the subject. There is an association of hypothyroidism, hyperthyroidism, thyroid nodules and cancer with radiation, but the threshold dose, mechanism of injury, and some risk factors have not been fully established. Children are more susceptible to thyroid injury caused by radiation and require prolonged follow-up after exposure. This issue is especially relevant nowadays, since a large number of people treated with radiation for childhood cancer survive and may have sequelae. Diagnostic radiology tests also represent a source of exposure to radiation in the pediatric population. In this review, we analyze different clinical and pathological changes, and the mechanisms of thyroid lesions caused by radiotherapy and computed tomography in children and adolescents. It is important to understand these data for prevention, early detection, and treatment of thyroid dysfunction.

Transient cytotoxicity of 131I beta radiation in hyperthyroid patients treated with radioactive iodine.

Background & objectives: Radioiodine (131I) or radioactive iodine in low doses is used worldwide as the first line of management in the treatment of hyperthyroidism. Information is available on the extent and severity of cell damage after a high dose radioiodine (131I) therapy for thyroid cancer, but information is scanty on its cellular effects, its extent and severity of cell damage after a low dose 131I therapy. The present investigation was aimed to study the cytotoxic effects of a low dose 131I therapy in varying doses as is normally being used in routine clinical practice in the treatment of various forms of hyperthyroidism. Methods: Peripheral blood lymphocytes were analyzed in 32 hyperthyroid patients. All of them received 131I in the form of sodium iodide solution orally. Blood lymphocytes were studied for the presence of chromosomal aberrations (CA) and micro nucleus (MN) using micronucleus assay. Blood samples of these patients were drawn prior to the treatment, on 7 thand 30 thdays after the treatment. Results: The results indicated a positive relationship between 131I dose, CA and MN frequency. A statistically significant increase in CA and MN frequency in day 7 post- therapy and a decrease in mean levels of CA and MN on day 30 post-therapy were observed when compared to pre-therapy. Interpretation & conclusions: This study showed that the cytogenetic damage induced by 131I in low doses i.e., less than 555MBq was minimal and reversible. Patients can be motivated to undertake this safe and easy procedure as a first line of therapy in the treatment of hyperthyroidism.

Niveles de dosis en radiología convencional / Radiation doses in conventional radiology

Se ha medido la dosis en la superficie de entrada de ojos, tiroides y gónadas en pacientes sometidos a estudio de radiografía de tele de tórax mediante dosimetría termoluminiscente. Se usaron 5 dosímetros en cada una de las exploraciones; encontrándose los siguientes rangos de dosis: 20 mGy a 350 mGy. En el caso de los pacientes pediátricos se propone incluir la información de las dosis recibidas en su cartilla de vacunación con el fin de hacer un seguimiento de los posibles efectos nocivos en su salud.

Doses have been measured at the entrance surface of eyes, thyroid and gonads in patients undergoing chest x-ray studies, using thermo-luminiscent dosimetry. Five dosimeters were used in each investigation, and doses ranged from 20 mGy to 350 mGy. In the case of pediatric patients, it is proposed that dose information from diagnostic examinations is included in the vaccination chart in order to correlate with findings at follow-up.

Thyroid hormones level before and after radiotherapy of neck in Imam Khomeini hospital of Ahvaz

Because of prevalence of head and neck cancer and extensive surgery in this area, complementary therapies in these patients are of particular importance. One of the most important complementary therapies is head and neck radiation therapy after surgery. Radiation therapy in head and neck can interfere on the thyroid gland function. The aim of this study is to determine the relationship between head and neck cancer radiotherapy and thyroid function after surgery. This study is an analytical epidemiological study on all patients who admitted for head and neck surgery in Imam Khomini hospital in 2007-2008. These patients candidate for complementary radiotherapy postoperatively. Exclusion criteria include: total for partial thyroidectomy, impaired thyroid function before radiotherapy and patients with a history of thyroid dysfunction. Levels of thyroid hormones [T3, T4, TSH] is recorded before and after radiotherapy. Age, sex, hormone levels before and after radiotherapy and the number of patients with hypothyroidism are reviewed. There was 60 patients, 34 women [56.6%] and 26 male [43.3%]. The mean age was 58.5 years, SD was 12.3. Thyroid tests in all patients were reported normal. Average amount of Total T3 before radiation therapy was 2.83 +/- 1.2 and after radiation therapy 1.74 +/- 0.9. P value level was 0.012. Average Total T4 levels before radiotherapy was 87.5 +/- 23.4 and after radiotherapy was 65.3 +/- 26.2. P value level was 0.003. Mean TSH levels before radiotherapy was 2.45 +/- 1.7 and after radiotherapy was 5.7 +/- 3.3. P value level was 0.000. 23 patients of 60 patients were hypothyroid [38%].There is a relationship between head and neck radiotherapy and hypothyroidism. We recommended controlling thyroid hormone function before and after treatment and then annually and also treating hypothyroidism if it occurred

Lack of Radiation Protection for Endoscopists Performing Endoscopic Retrograde Cholangiopancreatography / 대한소화기학회지

BACKGROUND/AIMS: ERCP using fluoroscopy should be practiced with an adequate radiation protection. However, the awareness of gastrointestinal endoscopists to radiation protection was considered insufficient. In Korea, a country with a rapid increase the number of ERCP procedures, there is no data about radiation protection practices for gastrointestinal endoscopists. The purpose of this study was to investigate current clinical practices and the awareness on radiation protection in ERCP performing physicians in Korea. METHODS: An anonymous questionnaire regarding radiation protection practices was mailed to 100 members of Korean Pancreatobiliary Association who was porforming ERCP. The questionnaire included ERCP volume of each endoscopist, use of protection devices such as apron, thyroid shield, lead glasses and any mobile shield for scattered radiation, and whether they monitored their own radiation exposure dosage. RESULTS: All respondents wore lead aprons during ERCP. While 52.5% of endoscopists answered that they always wear thyroid guards, 26.9% rarely or never wore it. Only 14% wore lead glasses during the procedure and 69% never wore it. The preparation rates of mobile shields or lead curtains were only 14% and 24%, respectively. Only 10% of endoscopists attached an X-ray badge and 66.7% never used it. Moreover, 75% of endoscopists responded that they did not monitor their own exposure dose to radiation during ERCP. CONCLUSIONS: The lack of radiation protection of ERCP endoscopists in Korea was seemed serious. Awareness of radiation hazard should be more concerned and educated in parallel with the preparation of radiation protection equipments.

Alteraciones estructurales de la glándula tiroidea tras la radioterapia / Structural alterations of thyroid gland after radiotherapy

El objetivo de la presente publicación fue comunicar los casos detectados en nuestro estudio de anomalías estructurales de la glándula tiroidea en pacientes que recibieron radioterapia para el tratamiento de tumores malignos de cabeza y cuello. Se realizó un estudio descriptivo de corte transversal para determinar la prevalencia de alteraciones estructurales de la glándula tiroides en 43 pacientes sobrevivientes de tumores malignos de cabeza y cuello, que habían recibido radioterapia y que fueron atendidos en los Hospitales Pediátricos Docentes William Soler y Juan Manuel Márquez en un período de 10 años (1990 a 2000). La alteración estructural de la glándula tiroides más frecuente fue la fibrosis glandular (18,5 por ciento), seguida del adenoma tiroideo y de quistes simples de la glándula (11,1 por ciento respectivamente). Hubo 2 casos de carcinoma diferenciado de la glàndula tiroides (7,4 por ciento) y uno de lesión mixta adenofolicular (3,7 por ciento). La citología aspirativa con aguja fina permitió la detección de la mayoría de estas lesiones y posibilitó, guiada por ecografía, la detección de lesiones intraparenquimatosas de la glándula. El tratamiento de las alteraciones encontradas fue quirúrgico y se practicó tiroidectomía total a los dos pacientes con carcinoma diferenciado de la glándula tiroides, tiroidectomía subtotal a los tres pacientes con quistes de la glándula y adenomas tiroideos. En los casos de fibrosis glandular se detectó hipofunción tiroidea concomitante, por tanto se administró tratamiento sustitutivo con levotiroxina. La citología aspirativa con aguja fina guiada mediante ecografía de la glándula tiroides permitió diagnosticar alteraciones estructurales no detectadas en el examen físico. La patología maligna más irradiada correspondió a los linfomas no Hodgkin. Cuanto mayor es la dosis de irradiación, mayor es la patología tiroidea.

Paper was to report cased detected in our study of structural anomalies of thyroid gland in patients underwent radiotherapy for treatment of malignant head and neck tumors. METHODS: A cross-sectional and descriptive study was carried out to determine prevalence of structural alterations of thyroid gland in 43 patients survival of head-neck tumors underwent radiotherapy admitted in William Soler and Juan Manual Màrquez Teaching Hospitals during 10 years (1990 to 2000). More frequent structural alteration of thyroid gland includes glandular fibrosis (18,5 percent) followed by thyroid carcinoma, and of simple cysts of that gland (11,1 percent respectively). There were 2 cases of differential carcinoma of thyroid gland (7, 4 percent), and one of adeno-follicular mixed injury (3, 7 percent). Fine-needle aspirate cytology allows detection of most of these injuries and also the intra-parenchymatous guided-echography of this gland. Treatment of injuries founded was surgical and we performed a total thyroidectomy in two patients presenting with differential carcinoma of thyroid gland, subtotal thyroidectomy in t here patients with cysts of that gland, and thyroid adenomas. In cases of glandular fibrosis there was a concomitant thyroid hypofunction, thus, we administered substitute treatment using Levothyroxine. Fine-needle aspiration cytology by means of echography of thyroid gland allows diagnosing of structural alterations no detected in physical examination. More irradiated malignant pathology was non-Hodgkin lymphomas. More doses of irradiation, more is thyroid pathology.

Dosis y Factores Gamma de una paciente con 131I / Doses and Gamma factors in a patient with 131I

Mediante métodos Monte Carlo se calcularon las dosis en los órganos internos de una mujer, con tres meses de embarazo, debidas al radioiodo captado por su tiroides, así como a 1 metro de la glándula. Se utilizó un modelo tridimensional del cuerpo de la mujer y mediante Monte Carlo, los fotones de radioiodo se transportaron isotrópicamente desde la tiroides hacia todo el cuerpo y se calculó la dosis absorbida por sus órganos internos. También se determinó el Kerma en aire (K) y la dosis equivalente ambiental (H*(10)) a 1 m de la glándula. Se determinaron dos factores de actividad a dosis, también llamados Factores Gamma, que permiten estimar la dosis que la paciente produce a personas a su alrededor. De la radiación gamma que emite el 131I en la tiroides se encontró que el timo recibe la mayor dosis mientras que el útero es el órgano que menor dosis recibe. Los factores gamma determinados fueron: ΓKAire = 52.06 μGy-m2-h-1-GBq-1, y ΓH*(10) = 67.72 μSv-m2-h-1-GBq-1. La distribución de la dosis absorbida por los órganos internos se atribuye a la distancia relativa entre la tiroides y los otros órganos, al blindaje inter-órganos, su tamaño y a su composición elemental. Los factores ΓKAire y ΓH*(10) permiten estimar la exposición que la paciente produce sobre el personal a su alrededor. Con esto, el médico nuclear, el físico médico o el responsable de la seguridad radiológica en el hospital pueden dar indicaciones mas precisas sobre el comportamiento de las personas en torno al paciente.

Estimating the Absorbed Dose to Critical Organs During Dual X-ray Absorptiometry

OBJECTIVE: The purpose of this study is to estimate a patient's organ dose (effective dose) during performance of dual X-ray absorptiometry by using the correlations derived from the surface dose and the depth doses in an anthropomorphic phantom. MATERIALS AND METHODS: An anthropomorphic phantom was designed and TLDs (Thermoluminescent Dosimeters) were placed at the surface and these were also inserted at different depths of the thyroid and uterus of the anthropomorphic phantom. The absorbed doses were measured on the phantom for the spine and femur scan modes. The correlation coefficients and regression functions between the absorbed surface dose and the depth dose were determined. The derived correlation was then applied for 40 women patients to estimate the depth doses to the thyroid and uterus. RESULTS: There was a correlation between the surface dose and depth dose of the thyroid and uterus in both scan modes. For the women's dosimetry, the average surface doses of the thyroid and uterus were 1.88 (micro)Gy and 1.81 (micro)Gy, respectively. Also, the scan center dose in the women was 5.70 (micro)Gy. There was correlation between the thyroid and uterus surface doses, and the scan center dose. CONCLUSION: We concluded that the effective dose to the patient's critical organs during dual X-ray absorptiometry can be estimated by the correlation derived from phantom dosimetry.

131I-induced changes in rat thyroid gland function

Therapeutic doses of 131I administered to thyrotoxic patients may cause thyroid failure. The present study used a rat model to determine thyroid function after the administration of different doses of 131I (64-277 µCi). Thirty male Fisher rats in the experimental group and 30 in the control group (untreated) were followed for 6 months. The animals were 4 months old at the beginning of the experiment and were sacrificed at an age of 9 months. Hormone concentration was determined before 131I administration (4-month-old animals) and three times following 131I administration, when the animals were 7, 8, and 9 months old. The thyroid glands were removed and weighed, their volume was determined and histopathological examination was performed at the end of the experiment. Significant differences in serum triiodothyronine and thyroid-stimulating hormone concentration, measured at the age of 7, 8, and 9 months, were found in the experimental group. During aging of the animals, the concentration of thyroxin fell from 64.8 ± 8.16 to 55.0 ± 6.1 nM in the control group and from 69.4 ± 6.9 to 25.4 ± 3.2 nM in the experimental group. Thyroid gland volume and weight were significantly lower in the experimental than in the control group. Thyroid glands from the experimental group showed hyaline thickness of the blood vessel wall, necrotic follicles, a strong inflammatory reaction, and peeling of necrotic cells in the follicles. In conclusion, significant differences in hormone levels and histopathological findings indicated prolonged hypothyroidism after 131I administration to rats, which was not 131I dose dependent.

The Chernobyl accident 20 years on: an assessment of the health consequences and the international response

Twenty years after the Chernobyl accident the WHO and the International Atomic Energy Authority issued a reassuring statement about the consequences. Our objectives in this study were to evaluate the health impact of the Chernobyl accident, assess the international response to the accident, and consider how to improve responses to future accidents. So far, radiation to the thyroid from radioisotopes of iodine has caused several thousand cases of thyroid cancer but very few deaths; exposed children were most susceptible. The focus on thyroid cancer has diverted attention from possible nonthyroid effects. The international response to the accident was inadequate and uncoordinated, and has been unjustifiably reassuring. Accurate assessment in future health effects is not currently possible in the light of dose uncertainties, current debates over radiation actions, and the lessons from the late consequences of atomic bomb exposure. Because of the uncertainties from and the consequences of the accident, it is essential that investigations of its effects should be broadened and supported for the long term. The United Nations should initiate an independent review of the actions and assignments of the agencies concerned, with recommendations for dealing with future international-scale accidents. These should involve independent scientists and ensure cooperation rather than rivalry.

Vinte anos após o acidente de Chernobyl ocorrido em 1986, a OMS e a Autoridade Internacional sobre Energia Atômica lançaram um relatório sobre as conseqüências desse desastre. Nosso objetivo neste estudo é avaliar o impacto de tal acidente sobre a saúde e a reação internacional sobre o ocorrido, além de considerar se é possível melhorar as respostas em futuros desastres. Observamos que a radiação sobre a tireóide, proveniente de radioisótopos de iodo, causou milhares de casos de câncer, mas poucas mortes; as crianças expostas foram as mais suscetíveis. O foco no câncer de tireóide, porém, distraiu a atenção de especialistas sobre outros possíveis efeitos. A resposta internacional ao acidente foi inadequada, descoordenada e injustificavelmente tranqüilizadora. Acurada avaliação sobre efeitos futuros nem sempre é possível por causa de uma certa dose de incertezas frente ao estágio atual dos debates sobre radiação. É essencial que investigações sobre efeitos e conseqüências do desastre possam ser socializadas e apoiadas por um longo período de tempo. Por causa das inadequadas respostas internacionais ao problema, a ONU deveria iniciar uma revisão independente a respeito das ações e responsabilidades das agências, com recomendações de como agir em futuros desastres. Isso deveria envolver cientistas independentes e não que atuassem em competição.

[Estimation of absorbed dose of uterus and thyroid in women based on scan center dose in radiation with DEXA pencil-beam system]

Dual energy X-ray absorptiometery [DEXA] is presently considered as the standard technique for diagnosis of osteoporosis. Since there is still no evaluation based on the correlation between scan center dose and critical organs doses, in this study after measuring surface doses of thyroid and uterus as critical organs the correlation between scan center dose and thyroid and uterus surface doses were calculated in order to assess the rate of radiation doze to patients. In this study, 40 women underwent bone densitometry of Lunar DPX-MD system with pencil beam in two scan modes of AP spine and femur, simultaneously. Then surface doses of thyroid, uterus, scan center, and background were measured by placing 433 TLDs-400 at the surface of thyroid and uterus and also scan center. Then correlation between scan center dose and critical organs surface dose were analyzed and regression functions with significant level were determined. In AP spine and femoral scanning, average surface doses of thyroid [91 TLD-400] and uterus [84 TLD-400] were 1.88 +/- 1.36 and 1.81 +/- 1.03 micro Gy, respectively. Scan center dose in this scanning mode was 5.70 +/- 2.38 micro Gy. There was significant correlation between surface doses of thyroid and uterus and scan center dose. Therefore, regression functions and correlation coefficients were calculated. The observed significant correlation between critical organs surface dose and scan center dose showed that Lunar DPX-MD with pencil beam has very low radiation, similar to background doses

Iatrogenc hypothyroidism: a consequence of external beam radiotherapy to the head & neck malignancies.

BACKGROUND: Hypothyroidism is a known consequence of external beam radiotherapy to the neck encompassing part or whole of the thyroid gland for over 40 years. Still thyroid function tests are not a part of routine follow up of head - neck cancer patients treated with radiotherapy with or without surgery and / or chemotherapy. AIM: Aim of this study was to find out the incidence of hypothyroidism in head - neck cancer patients treated with radiotherapy with or without chemotherapy where radiation portals included most or whole of the thyroid gland. MATERIALS AND METHODS: From September 2001 to November 2003, 187 patients with head-neck malignancies were treated with external beam radiotherapy whose radiation portals included part or whole of the thyroid gland with / without chemotherapy. Thyroid function tests were done at the beginning of treatment, at six weeks after completion of radiotherapy and thereafter at six weeks interval for two years. RESULTS: Out of 187 patients, five were excluded from the study as they were found to be hypothyroid before the initiation of treatment. Another four were excluded from result analysis because they underwent laryngectomy for uncontrolled disease. Of the patients attending the follow up clinic, 17.8 % and 21.8 % were found to have clinical and sub-clinical hypothyroidism at two year. CONCLUSION: As a significant number of patients develop hypothyroidism following radiotherapy to the neck, thyroid function tests should be included in the routine follow up protocol of such patients. But certain questions have emerged from this study which need a large randomized study to find out the answers.

Padronização de valores de captação tiroidiana com 123I / Reference values for thyroid 24 hours 123I uptake

Com o objetivo de padronizar valores de referência para captação tiroidiana (CAPTIR) com 123I, analisamos 475 pacientes que realizaram dosagens de T4 livre e TSH e exames de CAPTIR 24h após a administração de 123I. Separamos os pacientes em 3 grupos: hipertiróideo, normal e hipotiróideo, de acordo com os resultados do T4 livre e TSH. Calculamos as médias e os desvios-padrão (DP) dos valores de captação, realizamos testes t não-pareados e calculamos curvas ROC para definir os melhores valores de CAPTIR para separar os grupos. As médias e DP dos valores de captação foram: hipertiróideo (36,5 por cento ± 16,5 por cento), normal (14,4 por cento ± 5,48 por cento) e hipotiróideo (13,7 por cento ± 7,5 por cento). O teste t não-pareado mostrou diferença significativa entre os grupos hipertiróideo e normal (p< 0,01), sem diferença significativa entre os grupos normal e hipotiróideo (p= 0,55). O valor de captação 23 por cento apresentou melhor relação sensibilidade (80 por cento) / especificidade (93 por cento) para separar o grupo normal do hipertiróideo. A curva ROC não mostrou bons resultados para a separação do grupo normal do hipotiróideo. Em conclusão, o limite superior da normalidade para CAPTIR pode ser estabelecido em 23 por cento. Não foi possível estabelecer limite inferior de normalidade, devido à grande sobreposição dos valores de captação dos grupos hipotiróideo e normal.

Multinodular goiter management in Western Saudi Arabia

The aim of this study was to provide epidemiological data and summarize the different modalities of management of multinodular goiters [MNG] in the Western Province of Saudi Arabia [KSA]. A total of 135 patients had MNG, which were diagnosed by ultrasonography at King Abdul-Aziz University Hospital in Jeddah, KSA between January 2003 and June 2004. The data collected includes the age, gender, physical examination of the thyroid gland [trifluorothymidine, free thyroxine, free triiodothyronine, thyroid stimulating hormone], ultrasonographic findings and Tc99 radioiodine nuclear scan of the thyroid gland, fine needle aspiration [FNA] of the gland and antithyroid antibodies. The study group was divided according to the thyroid status: nontoxic euthyroid MNG, hypothyroid MNG and toxic hyperthyroid MNG. The management of MNGs according to the patients' clinical presentations and thyroid status was reviewed. The mean age was 39 +/- 12.66 years with a range of 10-79 years. Forty-two patients [31%], with no history of thyroid cancer, had ultrasoundguided FNA; 41 [97.6%] of the FNAs were benign. One FNA [2.3%] was positive for papillary carcinoma in a 56-year-old female patient. Thyroid antibodies [anti-microsomal antibodies and anti-thymoglobulin antibodies] were measured in 50 patients [37%]. Thirty-one [62%] were positive, 11 [35%] of which were positive in patients with documented hypothyroidism. All patients with hypothyroidism were treated with levothyroxine; however, only 25.6% with euthyroid MNG were treated with suppressive doses of levothyroxine. Twelve patients [44.4%] with toxic MNG were treated with antithyroid medications. Radioiodine therapy was not given to any patient with nontoxic MNG; however, 48% of those with hyperthyroid MNG received radioactive iodine treatment. Surgery was carried out in 25.6% of patients with euthyroid nontoxic MNG, and in 11 patients with toxic MNG. Nearly half of those with nontoxic MNG [46.5%] and 14.8% of those with a subclinical hyperthyroid MNG refrained from any therapy. They were followed-up by their clinician in the outpatient clinic. Serum thyroid stimulating hormone levels, ultrasound and fine needle biopsy were the cornerstones of the diagnostic evaluation of patients with MNG. Review of the management of these patients was comparable to that found in the literature. The treatment strategy was similar to the recommendations by the American Thyroid Society; however, radioactive iodine treatment was not used as a treatment for patients with nontoxic goiters

Tratamiento del hipertiroidismo con radioyodo: efecto de la dosis administrada sobre la función tiroidea y complicaciones asociadas / Treatment of hyperthyroidism with radioiodine: effects of administered dose on complications and thyroid function

Background: Radio-iodine is a definite therapy for Graves disease hyperthyroidism. However, the optimal dosage is still debatable. Aim: To assess the effects of different radioiodine doses on thyroid function and complications in patients with hyperthyroidism. Material and methods: A retrospective analysis of 139 patients with hyperthyroidism, treated with ratioiodine between 1988 and 1998. Radio iodine dose used was classified as low (<10 mCi), intermediate (10-14.9 mCi) or high (ü 15 mCi). Results: Thirty five patients were treated with low doses, 33 with intermediate doses and 71 with high doses. There were no differences between these patients in age, disease severity, frequency of post treatment euthyroidism or complications. Patients treated with low doses had a higher frequency of persistent hyperthyroidism than patients treated with high doses (25.7 and 4.2 percent respectively, p<0,001). Likewise, the frequency of subsequent hypothyroidism was 60 percent in patients treated with low doses and 84.5 percent of those with high doses, in whom it also appeared earlier. Associated complications were clinically irrelevant. In seven patients, Graves ophtalmopathy progressed after treatment, but this progression was not associated with the dose used. Conclusions: Radio iodine in high doses is useful, safe and effective for the treatment of Graves hyperthyroidism

Endolymphatic irradiation in preparation for renal transplantation: a 26-year follow-up

The aim of the present study was to analyze the long-term evolution of patients submitted to endolymphatic irradiation as a pre-transplant preparation. Setting: Referral center of university hospital. Design: Case-control study. Main outcomes measures: The study was designed to evaluate the incidence of rejection, kidney loss, leukopenia, infection, and graft survival in the group treated (group 1) prior to surgery, compared to a control group (group 2) composed of patients under identical clinical conditions (Sex, age, type of donor, immunosuppresive therapy and time of transplant) that did not undergo treatment preparation. Patients: Patients were selected from amongst transplatation candidates on a long-term waiting list, some with a high level of antibodies against panel. The control group was chosen from amongst recently transplanted patients. Patients in the treated group received lipoidine containing I with specific activity ranging between 4 and 6 mCu/ml. Results: A significant difference between the two groups was found with regard to the incidence of rejection crises (21.0 per cent in group 1 and 73.6 per cent in group 2; P=0.003), and the maintenance dose of azathioprine (smaller in group 1; P<0.01). As to kidney graft loss due to rejection, a tendency to significance could be identified (10.5 per cent in group 1 and 42.1 per cent in group 2; P=0.063); however, the difference was not significant the two groups in terms of reversibility of rejection episodes during the first 60 post-transplant days. Conclusions: The authors concluded that this method, besides being relatively innocuous (there was no compromising of either the thyroid gland or of gonad function and there was no increase in tumor incidence), has na extended immunosuppressive effect, and can be indicated for cadaveric renal allograft recipients, especially those showing high panel reactivity.