[Hyperthyroidism. Etiology, physiopathology, diagnosis, evolution, treatment].
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Adult↗
Biomedical subjects
A Aurengo
Publications and source records attributed to A Aurengo.
Iodine kinetics and effectiveness of stable iodine prophylaxis after intake of radioactive iodine: a review.
Ingestion of potassium iodide (KI) offers effective protection against irradiation of the thyroid after accidental exposure to radioactive iodine. This prophylaxis aims at rapidly obtaining maximal thyroid protection without adverse effects. This article reviews studies on iodine kinetics in humans and on the efficacy of KI in protecting the thyroid. In adults with normal thyroid function, ingestion of 100 mg of iodide just before exposure to radioactive iodine blocks at least 95% of the thyroid dose. If exposure persists after iodide ingestion (100 mg), the percentage of averted dose may decrease significantly. Daily ingestion of a dose of 15 mg of KI would then maintain the thyroid blockade at a level above 90%. The efficacy of iodide and the occurrence of antithyroid effects also depend on external and individual factors such as dietary iodine intake, thyroid function, and age. The KI dosage regimen should be adjusted for age at exposure. For the fetus, the newborn, children, and adolescents, the risk of radiation-induced thyroid cancer in case of accidental exposure to radioactive iodine justifies KI prophylaxis, despite the risk of hypothyroidism, especially in newborns. For the elderly, the benefits of KI may be lower than the risk of iodine-induced hyperthyroidism.
Dose-Response Relationship, Drug↗
Survival and therapeutic modalities in patients with bone metastases of differentiated thyroid carcinomas.
Data for patients with bone metastases (BMs) of differentiated thyroid carcinoma (DTC) were retrospectively studied to identify factors associated with survival. We especially studied the impact of therapies. Among the 1977 patients followed for DTC in our department from 1958 to 1999, 109 (77 females and 32 males; age range, 20--87 yr) presented BMS: All patients except 1 underwent total thyroidectomy, followed by radioiodine therapy (> or =3.7 gigabecquerels) in 95 cases. Survival rates at 5 and 10 yr were 41% and 15%, respectively. Univariate analyses indicated that a young age at BM discovery (P < 0.005) and the discovery of BM as a revealing symptom of DTC (P < 0.05) were features significantly associated with improved survival as well as radioiodine therapy (P < 10(-4)) and BM complete surgery (P < 0.02). Using multivariate analysis, the detection of BMs as a revealing symptom of thyroid carcinoma (P < 0.0005), the absence of metastasis appearance in other organs than bones during the follow-up (P < 0.03), the cumulative dose of radioiodine therapy (P < 0.0001), and complete BM surgery in young patients (P < 0.04) appeared as independent prognostic features associated with an improved survival.
Adult↗
Absolute activity quantitation in simultaneous 123I/99mTc brain SPECT.
UNLABELLED: Dual-isotope imaging can allow simultaneous assessment of brain perfusion using a 99mTc-labeled tracer and neurotransmission using an 123I-labeled tracer. However, the images are affected by scatter, cross talk, attenuation, distance-dependent collimator response (DCR), and partial-volume effect. We determined the accuracy and precision of activity quantitation in simulated normal and pathologic studies of simultaneous 123I/99mTc brain SPECT when compensating for all degrading phenomena. METHODS: Monte Carlo simulations were performed using the Zubal brain phantom. Contamination caused by high-energy 123I decay photons was incorporated. Twenty-four 99mTc and 123I activity distributions were simulated on the basis of normal and pathologic patient activity distributions. Cross talk and scatter were corrected using a new method based on a multilayer perceptron artificial neural network (ANN), as well as by the asymmetric window (AW) approach; for comparison, unscattered (U) photons of 99mTc and 123I were recorded. Nonuniform attenuation and DCR were modeled in an iterative ordered-subset expectation maximization (OSEM) algorithm. Mean percentage biases and SDs over the 12 normal and 12 pathologic simulated studies were computed for each structure with respect to the known activity distributions. RESULTS: For 123I, AW + OSEM yielded a bias of 7% in the cerebellum, 21% in the frontal cortex, and 36% in the corpus callosum in the simulated normal population. The bias was increased significantly in the striata of simulated pathologic studies (P < 0.05). The bias associated with ANN was significantly lower (<9% in these brain structures, P < 0.05). For 99mTc with AW + OSEM, the bias was 60% in the corpus callosum, 36% in the striata, and 18%-22% in the cortical lobes in the simulated normal population. This bias was <11% in all brain structures with ANN. In the simulated pathologic population, the bias associated with AW increased significantly in the cortical lobes to 55% (P < 0.05), although it did not change significantly with ANN. CONCLUSION: The accuracy and variability over simulated normal and pathologic studies of both 99mTc and 123I activity estimates were very close with ANN to those obtained with U + OSEM. ANN + OSEM is a promising approach for absolute activity quantitation in simultaneous 99mTc/123I SPECT.
Alzheimer Disease↗
[Thyroid cancer in patients with hyperthyroidism].
OBJECTIVE: The prevalence of thyroid carcinoma in hyperthyroidism remains controversial. The aim of this retrospective study was to evaluate prevalence. PATIENTS AND METHODS: The prevalence of thyroid carcinoma was studied in 861 patients operated for clinical or infraclinical hyperthyroidism between 1992 and 1999. One hundred and fifty patients had a hot nodule, 13 of them with an associated goiter. Four hundred five patients had Graves' disease and 306 had a multinodular goiter. Multiple sections were made in all surgical specimens for pathology study. RESULTS: Prevalence in solitary nodules was 1.45%. For Graves' disease patients, it was 4.1%. Prevalence among patients with multinodular goiter was 4.9%. Among the cancers, 83% were microcarcinoma. Parathyroid morbidity after subtotal and total thyroidectomy was 0.56% and recurrent hyperthyroidism occurred in 1.6%. CONCLUSIONS: These findings are grossly identical to those observed in simple, nontoxic diffuse multinodular goiter. It would therefore be difficult to incriminate hyperthyroidism as playing a causal role in the development of thyroid cancer. These results do however provide an argument favoring total or near total thyroidectomy when surgery is performed in patients with hyperthyroidism.
Adult↗
Fetal biometric parameters, twin type and birth weight difference. A longitudinal study.
OBJECTIVE: To examine the relationship between twin type, divided by zygosity, chorionicity, and birth weight difference [more or less than 15% intertwin weight difference at delivery] on fetal biometric measurements, including biparietal diameter, transverse abdominal diameter, head and abdominal circumferences (AC) and head and abdominal areas, femur length (FL), transverse cerebellar diameter, cerebellar circumference and cerebellar area at 18, 23, 28 and 32 weeks of gestational age. STUDY DESIGN: A prospective and longitudinal study was done on 75 twin pairs that did not present the twin-twin transfusion syndrome (150 fetuses) divided into birth weight difference group I (<15%) and group II (>/=15%). The twin pairs were divided into three groups: dizygotic, monochorionic, and dichorionic-monozygotic. In each group the differences in various ultrasound indices were evaluated in reference to discordant growth or concordant growth. RESULTS: In our sample, there were no monozygotic twin pairs with dichorionic placentation with a birth weight difference of more than 15%. Significant associations of group and gestational age were found in dizygotic and monochorionic twins. Intrapair differences were significantly higher in group II (>/=15%) than in group I (<15%) for all fetal parameters studied except for AC, abdominal area and all cerebellar parameters. The value of these discrepancies increased according to gestational age except for FL. Significant interactions between group and zygosity type indicated that intrapair FL differences were more associated with group in monochorionic twins, whereas intrapair transverse cerebellar diameter differences were more associated with group in dizygotic twins. CONCLUSION: Our data show that most fetal biometric parameters are associated with birth weight discordancy. Abdominal area could be a relevant marker for twins with obstetric complications. Note that this is the first research that has studied a twin sample divided by both twin type and birth weight group.
Biometry↗
Post-Chernobyl thyroid carcinoma in children.
The dramatic increase in childhood thyroid carcinoma observed in Belarus and Ukraine as early as 4 years after the Chernobyl nuclear accident, is well recognized as being a consequence of exposure to radioactive iodine fallout. Uncertainties persist concerning the contamination and the dosimetric data. Thyroid nodule, cervical lymph nodes or systematic ultrasound thyroid screening in exposed children led to the diagnosis. The carcinomas affected younger subjects, were less influenced by gender, and were more aggressive at clinical and histological presentation than in the case with naturally occurring carcinoma. Total thyroidectomy and radioiodine treatment remain the treatment of choice. The prognosis is good but further studies are needed to evaluate the prognosis of children presenting with pulmonary metastasis. The project of the Newly Independent States Chernobyl Tissue Bank will facilitate molecular genetic research into this important public health issue. Nevertheless, clinicians must keep in mind the simplicity and the effectiveness of iodine prophylaxis.
Adolescent↗
Pulmonary blood flow distribution in stage 1 chronic obstructive pulmonary disease.
We investigated the hypothesis that lung blood flow distribution is modified in stage 1 chronic obstructive pulmonary disease (COPD). We compared patients with stage 1 COPD (n = 11) with restrictive patients with comparable blood gases (n = 7), to patients with low cardiac index with normal lungs (n = 11) and to control subjects (n = 11). Distribution of transit time (DTT) was computed by deconvolution from first pass radioactivity curves (albumin (99m)Tc) reconstructed from right and left ventricular regions of interest. Distribution descriptors, mean transit time (p < 0.05), standard deviation (p < 0.001), relative dispersion (p < 0.001), and kurtosis (p < 0.001) differed between groups (ANOVA). Cardiac index was the same in COPD and low CI groups but lower compared with normal subjects (p < 0.05). After normalization for cardiac output, the DTT of patients with COPD remained different from low CI and restrictive patients (p < 0.001). Therefore changes in DTT in patients with COPD compared with patients without COPD could not be explained on the basis of difference in cardiac output. Because P(O(2)), PC(O(2)), and pH were similar in COPD and restrictive groups, difference in distribution could not be explained either on the basis of blood gas data. We conclude that changes in DTT occurs in stage 1 COPD and cannot be explained by hypoxemia, hypercapnia, or acidosis alone but must relate to other structural or regulatory responses.
Adult↗
Indications and limits of ultrasound-guided cytology in the management of nonpalpable thyroid nodules.
Although ultrasound (US)-guided fine needle aspiration biopsy (FNAB) is widely prescribed in nonpalpable thyroid nodules, the goal of this study was to define precisely the indications and limits of US-FNAB in a series of 450 nonpalpable nodules. Among 94 surgically controlled cases, 20 (8 infracentimetric and 12 centimetric or supracentimetric) carcinomas were diagnosed. The diagnosis of malignancy was successfully made by US-FNAB in 16 of 20 carcinomas, 3 were missed because of insufficient cytological material, and 1 was misdiagnosed. US-FNAB sensitivity and specificity were 94% and 63%, respectively. A logistic model indicated that nodule size (P < 0.6) was not associated with histological diagnosis, but that solid hypoechoic features were more likely to be malignant (P < 0.0003), with US sensitivity and specificity for malignancy of 80% and 70%, respectively. Logistic regression indicated that adequate cytological material significantly increased with nodule size (P < 0.0001). This result outlined the limits of US-FNAB in small nodules. Hence, indication of US-FNAB appears judicious in centimetric or supracentimetric nodules or in solid and hypoechoic ones. Such a management would allow the discovery of 15 of 20 carcinomas and would avoid 16% of unnecessary biopsies.
Adolescent↗
[What is the contribution of imaging?].
Thyroid imaging has an essentially diagnostic value, but is also plays a role in definition of indications and operative techniques. Ultrasound is the most useful examination. Scintigraphy has become less useful, but remains indicated in hyperthyroidism and in certain retrosternal goitres inaccessible to ultrasound. The other examinations only have a limited value.
Humans↗
Secondary thyroidectomy in patients with prior thyroid surgery for benign disease: a study of 203 cases.
BACKGROUND: The goal of this study was to evaluate the complication rate of secondary thyroidectomy in patients with prior thyroid surgery for benign disease. METHODS: Over an 8-year period, 203 thyroid reoperations were performed on 202 patients. All information relating to operative procedures, pathology, and complications was recorded prospectively. RESULTS: There were 24 men and 178 women with a mean age of 52 years. Prior surgery was unilateral in 136 cases (67%) and bilateral in 67 cases (33%), and 14 patients (6.9%) had more than 1 previous thyroid operation. For euthyroid or pretoxic recurrent nodular goiter, 190 reoperations were performed and 13 reoperations were performed for recurrent thyrotoxicosis. Twenty-three cancers were found in a specimen (11.4%). Completion thyroidectomy was done in 143 patients. Postoperative complications occurred in 21 patients (10.4%): recurrent laryngeal nerve palsy (7 patients), hypocalcemia (8 patients), hematoma requiring surgical evacuation (5 patients), and wound infection (1 patient). Complications remained permanent in 4 patients (2%). CONCLUSIONS: The permanent complication rate is higher in thyroid reoperations than in primary thyroid operations. However, we believe that this 2% rate is low enough to allow reoperation whenever it is necessary, provided precise operative rules are respected.
Adult↗
Twin differences and similarities of birthweight and term in the French Romulus population.
This study was performed to examine the main characteristics of the French Romulus twin population: zygosity, chorionicity, sex, term and birthweight. A sample of 104 pairs of twins was distinguished by zygosity, chorionicity and sex, and divided into concordant and discordant birthweight groups. Fifty-three % (n = 55) of the fetus pairs studied were born at "ideal term" (35-38 weeks), and 25% (n = 26) were delivered at "preterm" (28-34 weeks). The very preterm (< 28 weeks), and "postterm" (> 38 weeks) represented altogether 22% (n = 23) of the sample. Of the 104 twin pairs, 68% (n = 71) differ by less than 15% in birthweight, and 32% (n = 33) have a birthweight difference higher than 15%. In dizygotic (DZ) pairs females had more tendency to be in the discordant group (p = 0.01) while in monochorionic-monozygotic (MC-MZ) pairs males were more discordant (p = 0.07). We found a significant interaction between sex and zygosity type (p = 0.02). Males had a birthweight difference significantly weaker than that of females in dichorionic-monozygotic (DC-MZ) and DZ twins whereas it was higher than that of females in MC-MZ twins. There were no MZ twin pairs with DC placentation over than 15% birthweight difference. Log linear analysis demonstrated a three-way interaction (p < 0.05) between term type, zygosity type and hypotrophy. Our data indicate that in the group of twins born between 35 and 38 weeks' gestation the crucial question still remains unsettled on how term and birthweight are related to zygotism and/or chorionicity.
Birth Weight↗
Differential transferrin receptor density in human colorectal cancer: A potential probe for diagnosis and therapy.
Transferrin receptor density was investigated in human colorectal surgical specimens. Crude membranes were prepared from 23 cancer tumors (adenocarcinoma or malignant villous tumor) and 3 non-cancer tumors (polyadenoma or villous tumor) and 26 adjacent control mucosa. Contrary to non-cancer tumors, Scatchard analysis of 125I-transferrin binding data evidenced higher maximal transferrin binding capacity and lower dissociation constant in cancer tissues (Bmax cancer 1.828+/-0.320 nmol/g, Kd 24.1+/-4.7 nM), as compared to paired control colonic mucosa (Bmax contol 0.851+/-0.182 nmol/g, Kd 30.7+/-7.3 nM), paired t-tests: Bmax p<0.001, Kd p<0.05). As the cancer/control Bmax ratio was 2.6+/-0.4,transferrin carrier constructs should be proposed for cancer imaging or therapy.
Adult↗
Artificial neural network as a tool to compensate for scatter and attenuation in radionuclide imaging.
UNLABELLED: This study investigates the ability of artificial neural networks (ANN) to simultaneously correct for attenuation and Compton scattering in scintigraphic imaging. METHODS: Three sets of experiments are conducted using images of radioactive sources with various shapes and distributions in a homogeneous medium. Numerical Monte Carlo simulations and physical phantom acquisitions of radioactive geometric sources provide the basic material for correction. Our method is based on the following assumptions: information needed to correct for scattering can be extracted from the energy spectrum at each pixel without any assumption concerning the source distribution, and two diametrically opposed energy spectrum acquisitions yield enough information on the source location in the diffusing medium for simultaneous correction for attenuation and scattering. RESULTS: Qualitative and quantitative evaluations of scatter correction by ANN demonstrate its ability to perform scatter correction from the energy spectra observed in each pixel. By using the energy spectra of incident photons detected in two diametrically opposed images, multilayer neural networks are able to perform a proper restitution of projection images without any assumption on geometry or position of radioactive sources in simple geometric cases. ANN corrections compare favorably to those provided by five of the most popular methods. A satisfying correction of both scatter and attenuation is observed for a human pelvis scan obtained during routine clinical practice. CONCLUSION: An ANN is an efficient tool for attenuation and Compton scattering in simple model cases. The results obtained for routine scintigrams in a much more complex situation are strong incentives for performing further studies.
Bone and Bones↗
[Management of 29 children with thyroid cancer following the Chernobyl accident].
As a consequence of the Chernobyl nuclear power plant accident, a considerable increase of thyroid cancer among contaminated children has been reported in Ukraine, Belarus and Russia. A group of 29 children aged from 5 months to 10 years (mean 4.7 years) at the time of the accident, with a papillary thyroid cancer, have been examined at the Pitié-Salpêtrière hospital in Paris. The cancer was discovered by systematic ultrasonography in only 25% of cases. No reliable dosimetric estimation was achieved. The initial surgical treatment was performed in Ukraine. Cervical lymph node and pulmonary metastases were present in 24 and 11 cases respectively. A complementary surgical treatment was necessary for 9 children and one to four radioiodine treatments were given to 24 children. With a mean delay of 7 years after the cancer discovery, an apparent cure or a remission was obtained for 20 children, 6 children have cervical lymph node metastases requiring a surgical treatment and 3 have evolving lung metastases. The management of the great number of foreseeable cases of thyroid cancer requires an improved systematic screening, a large number of rooms dedicated to high activity radioiodine treatments, funds for disposable material and training missions.
Child↗
[Repeated thyroid surgery. Indications and results].
OBJECTIVES: To analyze the histology results and to assess operative risk of iterative operations for thyroid surgery. PATIENTS AND METHODS: A total of 249 re-operations were performed in 248 patients over a 6.5 year period. Two groups of patients were defined according to the indications for re-operation. Group 1: 80 patients; pathology examination of the surgical specimen discovered thyroid cancer. Group 2: 169 patients; recurrent nodular goitre after an initially benign disease. RESULTS: In group 1, 14 cancers were bilateral (17.5%) and 7 patients had cervical node metastases (8.8%). In group 2, 19 cancers were discovered (11.1%), including 5 cases with cervical node invasion (26.3%) and 4 with visceral metastases (21.1%). Twenty complications occurred in 20 patients (8%): compressive cervical hematomas (n = 3, 1.2%), recurrent nerve palsy (n = 7, 2.8%), hypoparathyroidism (n = 9, 3.6%; including 3 definitive cases, 1.2%) and mediastinitis (n = 1). These complications were significantly more frequent in patients re-operated for hyperthyroidism or those who had a past history of more than one cervicotomy. CONCLUSION: The frequency of bilateral cancer justifies completing thyroidectomy after partial thyroidectomy. The rate of definitive complications after re-operations is greater than first line cervicotomy but is low enough to allow iterative surgery using rigorous procedure in selected patients.
Goiter, Nodular↗
[Struma ovarii or malignant ovarian goiter. A case].
BACKGROUND: We report a case of follicular struma ovarii observed in an ovary teratoma without metastatic dissemination. CASE REPORT: A right ovarian tumor was discovered at ultrasound examination in a 31-year-old woman complaining of low abdominal pain. The patient underwent laparoscopic exploration and a 4-cm cystic mass of the right ovary was removed. Microscopic examination showed a malignant struma ovarii of the follicular type with vascular space invasion; other teratomous elements were identified. Immunohistochemical staining for thyroglobulin confirmed the nature of the tumor. The patient was treated by complete right ovariectomy followed by total thyroidectomy and administration of radioactive iodine (99 mCi I-131). Repeat I-131 body scan performed at 6 months was normal. DISCUSSION: Struma ovarii is a rare type of ovarian teratoma, consisting mainly of thyroid tissue. The incidence of malignant struma ovarii is below 1% and fewer than two dozen cases with distant metastases have been reported. The major problem associated with struma ovarii has been the establishment of criteria for malignancy.
Adult↗
Non-invasive assessment of technetium-99m albumin transit time distribution in the pulmonary circulation by first-pass angiocardiography.
This study describes a non-invasive method for assessment of the lung transit time distribution of a tracer, using first-pass technetium-99m albumin angiocardiography and a model-free method of deconvolution. Ten patients received a first injection of 1 MBq kg-1 in the external jugular vein to position a gamma camera in the left anterior oblique position and two additional injections (5 MBq kg-1) to record first-pass angiocardiographic data. Right and left ventricular time-activity curves were derived from regions of interest every 0.5 s over a 1-min period. The left ventricular curve was deconvoluted by the right ventricular curve to obtain the lung transport function. The deconvolution procedure was based on a modified version of the Kalman filtering technique. The procedure was repeated at an interval of 30 min in eight patients. Two patients were re-examined up to 2 years later. Skewness, kurtosis and relative dispersion of the distributions did not change over time. We also found that the distribution, once normalized by its first moment, was independent of isolated changes in heart rate or cardiac output. Comparison of curve shapes at an interval of 30 min by point by point analysis demonstrated the reproducibility of the technique. We conclude that computation of the pulmonary transit time distribution of 99mTc-albumin from a standard angiocardiography procedure by model-free deconvolution is reliable and reproducible over time. We suggest that it may be a valuable tool for the non-invasive follow-up of the pulmonary circulation.
Adult↗