Emese Mezosi

The role of technetium-99m methoxyisobutylisonitrile scintigraphy in the differential diagnosis of cold thyroid nodules

Abstract. Various diagnostic techniques have been successfully used in the clinical management of cold nodules; however, the decision on whether to employ surgery or a conservative treatment is not always easy. This study was designed to appraise the diagnostic value of technetium-99m methoxyisobutylisonitrile (MIBI) scintigraphy in the assessment of cold nodules detected using 99mTc-pertechnetate. Fifty-two patients were included in the study. All had already been selected for surgery, based on their clinical and laboratory findings, including fine-needle aspiration biopsy. The total number of cold nodules on 99mTc-pertechnetate scans was 59. The thyroid scan was performed 20-40 min after i.v. injection of 400 MBq of 99mTc-MIBI. Uptake of MIBI in thyroid nodules was compared with that in the surrounding normal thyroid tissue, and a score of between 0 and 3 was assigned to each nodule as follows: 0, cold; 1, decreased; 2, equal; 3, hot. Definitive histology revealed nodular goitre in 24 cases, adenoma in 19, thyroiditis in 1, differentiated cancer in 12, medullary cancer in 2, and anaplastic cancer in 1. None of the degenerative nodules were hot on MIBI scan, while the adenomas showed a variety of MIBI imaging patterns, most frequently the score 3 pattern. In the diagnosis of differentiated thyroid cancer the sensitivities of score 3 and score 2+3 MIBI uptake patterns were 83% (10/12) and 100%, respectively. The score 3 MIBI uptake pattern had a specificity of 100% and a positive predictive value of 100% with respect to thyroid (benign and malignant) neoplastic diseases, whereas a specificity of 72% and a positive predictive value of 43% were observed in the detection of differentiated cancer. After a cold nodule had been detected using 99mTc-pertechnetate, a second scan with high MIBI uptake increased by 7.8 times the probability that this nodule would be a differentiated cancer. In conclusion, 99mTc-MIBI scintigraphy is a useful method in the differential diagnosis of cold thyroid nodules if the primary aim is to differentiate degenerative from neoplastic diseases rather than to differentiate benign from malignant nodules. High MIBI uptake considerably increases the probability of a differentiated thyroid cancer and facilitates immediate surgical removal, while decreased uptake actually excludes it. We suggest a combination of fine-needle aspiration biopsy and MIBI scan as a routine diagnostic approach to cold thyroid nodules.

Technetium-99m-sestamibi/pertechnetate subtraction scintigraphy vs ultrasonography for preoperative localization in primary hyperparathyroidism

Abstract. A prospective study was performed to evaluate the efficacy of technetium-99m-sestamibi and technetium-99m-pertechnetate subtraction scanning and US for imaging parathyroid glands in primary hyperparathyroidism. Sixty-three patients were surgically treated for primary hyperparathyroidism (HPT). Preoperative scintigraphy and US were performed in all cases. Bilateral neck exploration was carried out on each patient. Results of radionuclide studies and US were compared with surgical and histological findings. In 57 patients with primary HPT the radionuclide scanning gave true-positive results. Four false-negative and two false-positive scintigrams were obtained. The sensitivity and the positive predictive value (PPV) of scintigraphy were 93 and 97%, respectively. Forty-one cases were correctly localized by the US. Seventeen US results were false negative and five were false positive. The sensitivity and the PPV for US were 71 and 89%, respectively. There was a statistically significant difference between the sensitivity of the scintigraphy compared with the US (p=0.001). Sensitivities of radionuclide scans and US were higher for adenomas (100 and 83%) than for hyperplastic glands (75 and 40%). The sensitivity of technetium-99m-sestamibi and technetium-99m-pertechnetate subtraction scintigraphy was significantly higher compared with US. This sensitive method could help surgeons in performing a rapid and directed parathyroidectomy.

Relationship of Serum Resistin Level to Traits of Metabolic Syndrome and Serum Paraoxonase 1 Activity in a Population with a Broad Range of Body Mass Index

UNLABELLED The relationship between resistin, one of the adipokines, and metabolic syndrome is not fully elucidated. Altered activity of the HDL-associated antioxidant enzyme paraoxonase 1 (PON1) that participates in the antioxidant defense mechanisms of HDL may have an important role in the obesity-related accelerated atherosclerosis. Inverse associations of PON1 with obesity and serum levels of leptin have been demonstrated. Our aim was to investigate the association of serum levels of resistin with (i) PON1 activity, and (ii) parameters of metabolic syndrome, including some that are additional for research. A total of 74 Caucasian subjects were recruited into the study and divided into 3 age and sex-matched groups. Group 1, 25 non-diabetic overweight/obese subjects with BMI of 28-39.9 kg/m (2); group 2, 25 non-diabetic obese patients with BMI >or=40 kg/m (2); and the control group 3, 24 healthy, normal-weight control subjects. Serum levels of resistin were correlated negatively with BMI (r=-0.27, P<0.05), waist circumference (r=-0.28, P<0.05), serum levels of leptin (r=-0.28, P<0.05), non-esterified fatty acids (NEFA) (r=-0.23, P<0.05), and HbA (1C) (r=-0.26, P<0.05), systolic BP (r=-0.28, P<0.05), and lipid peroxidation (measured by TBARS) (r=-0.40, P<0.01), and correlated positively with PON1 (r=0.24, P<0.05). No association was detected between the serum concentrations of resistin and the following investigated parameters: diastolic BP, levels of uric acid, glucose, insulin, or insulin resistance (measured by homeostasis model assessment, HOMA-IR), triglyceride, total cholesterol, LDL-C, and HDL-C. During multiple regression analyses BMI and TBARS were independent predictors of PON1, while age, gender, blood pressure, HOMA-IR, LDL-C, HDL-C, and resistin were not. CONCLUSIONS Among the study subjects, serum levels of resistin showed a positive, although not independent correlation with serum PON1, and a negative correlation with numerous parameters of the metabolic syndrome (i.e. adiposity, blood pressure, levels of leptin, free fatty acid, glycosylated hemoglobin, and lipid peroxidation). BMI and TBARS are independent predictors of PON1 activity.

Addition of chlorine during water purification reduces iodine content of drinking water and contributes to iodine deficiency

Drinking water is the major natural source of iodine in many European countries. In the present study, we examined possible sites of iodine loss during the usual water purification process. Water samples from 6 sites during the technological process were taken and analyzed for iodine content. Under laboratory circumstances, prepared iodine in water solution has been used as a model to test the effect of the presence of chlorine. Samples from the purification sites revealed that in the presence of chlorine there is a progressive loss of iodine from the water. In the chlorine concentrations employed in the purification process, 24-h chlorine exposure eliminated more than 50% of iodine when the initial iodine concentration was 250 µg/l or less. Iodine was completely eliminated if the starting concentration was 16 µg/l. We conclude that chlorine used during water purification may be a major contributor to iodine deficiency in European communities.

Associations of Adiponectin with Paraoxonase 1 and sE-Selectin in Hemodialyzed Patients

Background/Aims: In hemodialyzed (HD) patients, adiponectin and sE-selectin levels are elevated, while antioxidant paraoxonase 1 activity (PON1) is decreased. We determined if the hyperadiponectinemia in HD patients has a protective effect on the decrease in PON1 and elevation in sE-selectin in kidney failure. Methods and Design: Predialysis serum adiponectin, PON1 and sE-selectin as well as other metabolic variables were measured in 70 HD patients. Results: Adiponectin had (1) no association with PON1 or sE-selectin, (2) a positive association with dialysis efficiency and HDL-C, and (3) an inverse association with BMI, waist circumference, HOMA IR, triglyceride, hsCRP, fibrinogen, and albumin. Moreover, albumin, BMI, and HOMA-IR were independent negative predictors of adiponectin. Conclusions: In kidney failure, in contrast to normal renal function, higher adiponectin levels had no correlation with PON1 activity or the sE-selectin level. However, adiponectin has an association with dialysis efficiency and, similar to individuals with preserved kidney function, traits of metabolic syndrome. In addition to BMI and HOMA-IR, the serum albumin concentration is also one of the independent negative predictors of the serum adiponectin level. Collectively, these findings may add details to the understanding of the role that adiponectin plays in chronic renal disease related to ‘reverse epidemiology’.

The impact of post-radioiodine therapy SPECT/CT on early risk stratification in differentiated thyroid cancer; a bi-institutional study

Objective SPECT/CT has numerous advantages over planar and traditional SPECT images. The aim of this study was to evaluate the role of post-radioiodine therapy SPECT/CT of patients with differentiated thyroid cancer (DTC) in early risk classification and in prediction of late prognosis. Patients and methods 323 consecutive patients were investigated after their first radioiodine treatment (1100–3700 MBq). Both whole body scan and SPECT/CT images of the head, neck, chest and abdomen regions were taken 4–6 days after radioiodine therapy. Patients were re-evaluated 9–12 months later as well as at the end of follow up (median 37 months). Results Post-radioiodine therapy SPECT/CT showed metastases in 22% of patients. Lymph node, lung and bone metastases were detected in 61, 13 and 5 patients, respectively, resulting in early reclassification of 115 cases (36%). No evidence of disease was found in 251 cases at 9–12 months after radioiodine treatment and 269 patients at the end of follow-up. To predict residual disease at the end of follow-up, the sensitivities, specificities and diagnostic accuracies of the current risk classification systems and SPECT/CT were: ATA: 77%, 47% and 53%; ETA: 70%, 62% and 64%; SPECT/CT: 61%, 88% and 83%, respectively. There was no difference between cohorts of the two institutions when data were analyzed separately. Conclusions Based on our bi-institutional experience, the accuracy of post-radioiodine SPECT/CT outweighs that of the currently used ATA and ETA risk classification systems in the prediction of long-term outcome of DTC.

Szomatosztatinreceptor-ligandok helye az acromegalia kezelésé ben

Acromegaly is a rare disease with typical clinical manifestations. Untreated acromegaly carries a 2-4-fold increase in mortality in long-term outcome. The goal of treatment is double, including biochemical control of the disease (normalization of serum IGF1 levels compared to age and gender matched controls, GH levels below 1 ng/ml after oral glucose load, or random GH below 2.5 ng/ml) and control of the tumor mass. The therapeutic modalities currently available for the treatment of acromegaly are: surgery, medical therapy, radiation therapy and their combinations. The cornerstones of medical therapy in acromegaly are the somatostatin receptor ligands due to their effectiveness in controlling GH excess in 60-70 % of patients and their beneficial effects on tumor volume. Somatostatin analogues have an established role as adjuvant therapy after non-curative surgery, and evidence suggests their use as primary treatment for selected patients. The long-term use of somatostatin receptor ligands is safe and they are well tolerated. Future medical therapy consists of pasireotide, a novel, universal somatostatin receptor agonist, and a new class of drugs named dopastatins. The latter so-called chimeric molecules have strong affinity for somatostatin receptors and dopamine-2 receptors, resulting in a more effective blocking of GH secretion, according to preliminary data. The authors of this paper review the current medical therapy of acromegaly, focusing on the role of somatostatin receptor ligands.