Management of simple nodular goiter: current status and future perspectives

Observer variability in the sonographic evaluation of thyroid nodules

OBJECTIVE

Inter- and intraobserver variabilities in the description and diagnostic categorization of sonographic (US) features of thyroid nodules were evaluated.

METHODS

The current study was conducted on 72 malignant nodules and 61 benign nodules. The US findings for each thyroid nodule were analyzed twice at a 6-week interval by five radiologists. The analyses were in accordance with the guidelines proposed by the Thyroid Study Group of the Korean Society of Neuroradiology and Head and Neck Radiology (TSGKSNRHNR). Inter- and intraobserver variabilities were calculated using Cohen's kappa statistics. The sensitivity, specificity, positive-predictive value, and negative-predictive value in the assessment of the diagnostic accuracy using these guidelines were calculated.

RESULT

The interobserver agreement was fair to substantial for US features and categorization. Of the US features of the thyroid nodules, internal content (solid versus cystic) showed substantial agreement (k = 0.64). There was moderate agreement with regard to shape, echogenicity, calcification, and diagnostic categories (k = 0.42, 0.57, 0.55, and 0.55, respectively). There was fair agreement for margin, echotexture, and capsule invasion (k = 0.34, 0.26, and 0.32, respectively). With regard to intraobserver agreement, there was moderate to substantial agreement for all US features except for echotexture and capsule invasion, which showed fair agreement. In particular, there was moderate to almost perfect agreement for the diagnostic category. The sensitivity, specificity, positive-predictive value, and negative-predictive value were 65.3%-81.9%, 60.7%-68.9%, 69.7%-73.8%, and 66.6%-75.5%, respectively.

CONCLUSION

There were high degrees of inter- and intraobserver agreement using the "Guidelines for diagnostic thyroid ultrasonography," of the TSGKSNRHNR in the description and categorization of thyroid nodules.

Benign predominantly solid thyroid nodules: prospective study of efficacy of sonographically guided radiofrequency ablation versus control condition

OBJECTIVE

The purpose of this study was to evaluate the efficacy of radiofrequency ablation of benign predominantly solid thyroid nodules by comparing the findings in treatment and control groups.

SUBJECTS AND METHODS

Thirty patients with normal thyroid function, each with a benign predominantly (> 50%) solid thyroid nodule causing pressure symptoms or cosmetic problems, were assigned to a control group (n = 15) or to a group undergoing a single session of radiofrequency ablation (n = 15). Thyroid nodule volume, thyroid function, pressure symptoms, and cosmetic concerns were evaluated before treatment and during follow-up. Sonographically guided radiofrequency ablation was performed with an internally cooled electrode (1-cm active tip) with an output power of 30-80 W.

RESULTS

The control group had no resolution of symptoms or cosmetic problems. The mean nodule volume increased slightly after 6 months but without statistical significance (p = 0.46). In the radiofrequency ablation group, the mean symptom score (p = 0.001) and cosmetic grade (p = 0.001) improved significantly. Mean nodule volume decreased significantly from 7.5 +/- 4.9 mL (range, 1.7-20.0 mL) to 1.3 +/- 0.8 mL (range, 0.2-2.6 mL) 6 months after radiofrequency ablation (p = 0.001). There were no major complications of ablation.

CONCLUSION

This study confirmed that radiofrequency ablation is effective for reducing nodule volume and relieving nodule-related clinical problems and that an effect due to spontaneous nodule reduction can be excluded owing to the results of the comparison with a similar control group.

The utility of preoperative serum thyroid-stimulating hormone level for predicting malignant nodular thyroid disease

INTRODUCTION

The aim of this study was to assess whether serum thyroid-stimulating hormone (TSH) levels are of value in predicting malignancy in patients with nodular thyroid disease (NTD).

METHODS

Patients with NTD and a preoperative TSH level who underwent thyroidectomy between 1990 and 2008 were identified from a prospective database. Age, sex, TSH concentration, nodule size, and pathology were evaluated. Logistic regression analysis was used to determine which factors were predictive of malignancy.

RESULTS

Six hundred fifty-three patients were analyzed. The overall rate of malignancy was 20%; the rate was highest in patients<30 years (32%). The mean TSH level was higher in the malignant group (5.5 microIU/mL vs 1.4 microIU/mL, P<.0001). The rate of malignancy was 65% in patients with TSH levels>5.5 microIU/mL. Logistic regression analysis revealed that TSH level was the only significant risk factor for malignancy.

CONCLUSION

The serum TSH level may be useful in predicting the probability of cancer and optimizing the extent of thyroidectomy in patients with NTD.

Multispectral microscopy and cell segmentation for analysis of thyroid fine needle aspiration cytology smears

This paper discusses the needs for automated tools to aid in the diagnosis of thyroid nodules based on analysis of fine needle aspiration cytology smears. While conventional practices rely on the analysis of grey scale or RGB color images, we present a multispectral microscopy system that uses thirty-one spectral bands for analysis. Discussed are methods and results for system calibration and cell delineation.

Are endogenously lower serum thyroid hormones new predictors for thyroid malignancy in addition to higher serum thyrotropin?

It is well known that TSH plays a major role in the secretion of thyroid hormones, maintenance of thyroid specific gene expression, and gland growth. In this study, we aimed to evaluate association between tests of thyroid functions (fT3, fT4, TSH) and differentiated thyroid carcinoma. 441 patients operated for nodular goiter between 2005 and 2008 were analyzed. Thyroid functions were studied in the period of 1-30 days prior to surgery. In postoperative histopathological examination, differentiated thyroid carcinoma and benign thyroid disease were detected in 166 (37.6%) and 275 (62.4%) patients, respectively. Patients with thyroid malignancy had significantly lower serum fT3 (P = 0.001), lower fT4 (P = 0.022), and higher TSH levels (P < 0.001) compared to patients with benign disease, although all analytes were within the normal range. We subdivided by quartile serum fT3, fT4, and TSH in normal limits into three groups. The odds ratio (ORs) for the risk of thyroid cancer with a serum TSH between 0.63 and 1.67 μIU/ml and 1.68-4.00 μIU/ml, compared with a serum TSH between 0.40 and 0.62 μIU/ml were calculated as 2.60 (95% CIs 1.49-4.54) and 6.50 (95% CIs 3.51-12.03), respectively. There was also a greater risk of thyroid cancer in patients with fT3 levels of 1.57-3.00 pg/ml, compared with patients with fT3 levels of 3.89-4.71 pg/ml (OR 2.95, 95% CIs 1.68-5.20). For fT4, OR for the risk of thyroid cancer between 0.85 and 1.17 ng/dl compared with 1.48-1.78 ng/dl was 2.14 (95% CIs 1.22-3.74). In conclusion, lower fT3, fT4, and higher TSH concentrations within normal limits were related with increased thyroid cancer independent from sex and nodule type. Particularly, the association between lower fT3, fT4 levels and a diagnosis of thyroid cancer is a novel finding.

Thyrotropin serum concentrations in patients with papillary thyroid microcancers

BACKGROUND

Recent studies have shown that elevated serum thyrotropin (thyroid-stimulating hormone [TSH]) concentrations are associated with an increased risk of differentiated thyroid cancers in patients with nodular goiter. Therefore, the measurement of TSH concentrations might support the clinical estimation of cancer risk, especially in patients with thyroid nodules that are too small for fine-needle aspiration biopsies. Thus, the objective of this study was to compare preoperative serum TSH concentrations in patients with papillary thyroid microcarcinoma (PTMC) and individuals in whom the presence of even small differentiated thyroid cancers was excluded by thorough histological examination of the thyroid after total thyroidectomy because of medullary thyroid carcinoma or c-cell hyperplasia.

METHODS

The study was a retrospective cross-sectional analysis. Thirty-three patients with PTMC who had undergone a hemi- or total thyroidectomy and 54 subjects with medullary thyroid carcinoma or c-cell hyperplasia in whom a total thyroidectomy had been performed between 1994 and 2008 were included. Exclusion criteria were the intake of medication that might affect thyroid function and previous thyroid cancer or thyroid surgery.

RESULTS

The mean TSH value was comparable between patients with PTMCs (1.40 +/- 0.92 mLU/L, 95% CI = 1.07-1.72) and the control group (1.43 +/- 1.44 mLU/L; 95% CI = 1.04-1.82, p = 0.912). There was a positive trend in correlation between nodule size and TSH levels in patients with PTMC (p = 0.066).

CONCLUSIONS

TSH is not elevated in subjects with PTMCs, indicating that it is not likely involved in the de novo oncogenesis of these small cancers. However, TSH might rather play a role in the progression of preexisting PTMCs.

Utility of the ultrasound elastographic systolic thyroid stiffness index in reducing fine-needle aspirations

OBJECTIVE

The purpose of this study was to evaluate whether ultrasound elastography performed by using carotid pulsation as a compression source and generating the systolic thyroid stiffness index (STSI) can be used as a pre-fine-needle aspiration (FNA) screening tool.

METHODS

Ultrasound data previously acquired from 62 thyroid nodules in 59 patients who underwent a thyroid FNA were used. Pulsation from the carotid artery was used as the compression source, and the strain was calculated offline. A metric called the STSI was computed for each nodule during systole. On the basis of the derived STSI value, thyroid nodules were retrospectively classified into 2 types: I, no FNA (observation only); and II, FNA.

RESULTS

The STSI value of malignant nodules (n = 12) was significantly higher than that of benign nodules (n = 39; P < .00002). Using an STSI cutoff value of 10, 31 nodules were classified as type I, all of which were benign, whereas 20 nodules were classified as type II, 12 malignant and 8 benign, with sensitivity of 100% and specificity of 79.4%. This suggests that ultrasound elastography could have screened out 31 type I nodules, reducing the number of FNAs by 60.8%.

CONCLUSIONS

Thyroid ultrasound elastography has the potential to substantially reduce the number of FNA biopsies by detecting type I benign nodules. Patients with suspicious type II nodules would be referred for an FNA. Future prospective studies are needed to confirm the efficacy of thyroid ultrasound elastography as a triage tool to FNA.

Dose-dependent acute effects of recombinant human TSH (rhTSH) on thyroid size and function: comparison of 0.1, 0.3 and 0.9 mg of rhTSH

CONTEXT

Recombinant human TSH (rhTSH) is used to augment the effect of radioiodine therapy for nontoxic multinodular goitre. Reports of acute thyroid swelling and hyperthyroidism warrant safety studies evaluating whether these side-effects are dose dependent.

OBJECTIVE

To determine the effects on thyroid size and function of various doses of rhTSH.

DESIGN

In nine healthy male volunteers, the effect of placebo, 0.1, 0.3 and 0.9 mg of rhTSH was examined in a paired design including four consecutive study rounds.

MAIN OUTCOME MEASURES

Main outcome measures were evaluated at baseline, 24 h, 48 h, 96 h, 7 days and 28 days after rhTSH and included: Thyroid volume (TV) estimation by planimetric ultrasound, and thyroid function by serum TSH, free T3, free T4 and Tg levels.

RESULTS

Following placebo or 0.1 mg rhTSH, the TV did not change significantly from baseline at any time. At 24 and 48 h after administration of 0.3 mg rhTSH, the TV increased by 37.4 +/- 12.3% (SEM) (P = 0.03) and 45.3 +/- 16.1% (P = 0.05) respectively. After 0.9 mg rhTSH, the TV increased by 23.3 +/- 5.8% (P = 0.008) and 35.5 +/- 18.4% (P = 0.02) respectively. The increase in serum FT3, FT4 and thyroglobulin (Tg) was greater when administering 0.3 mg compared with 0.1 mg (P = 0.02) and when administering 0.9 mg compared with 0.3 mg (P = 0.02). After 0.1 mg rhTSH, the increase in FT3 and Tg was not significantly different from placebo whereas the FT4 increase was significantly higher (P = 0.02 compared with placebo).

CONCLUSIONS

In healthy individuals, rhTSH-induced thyroid swelling and hyperthyroidism is rapid and dose dependent. If valid for patients with goitre, our results suggest that these adverse effects are unlikely to be of clinical significance, following doses of rhTSH of 0.1 mg or less.

Use of color Doppler ultrasonography for the prediction of malignancy in follicular thyroid neoplasms: systematic review and meta-analysis

OBJECTIVE

The purpose of this systematic review was to obtain summary estimates of the diagnostic accuracy of color Doppler ultrasonography (CDU) in predicting malignancy in thyroid follicular neoplasms (FNs).

METHODS

We searched Medical Subject Headings together with the search terms "follicular," "thyroid," and "Doppler" in the MEDLINE, Web of Science, and Excerpta Medica databases as well as the Latin American and Caribbean Health Sciences Literature database, after which we performed manual searches of the reference lists to locate additional studies. There were no language restrictions. We included studies that assessed the diagnostic accuracy of CDU in identifying malignancy in thyroid FNs. The assessments of the quality and extraction of data were performed by 3 independent reviewers.

RESULTS

We included 4 studies, which collectively evaluated 457 thyroid FNs, 67 of which had been classified as malignant based on the evaluation of surgical biopsy samples. Moderate, rich, predominant, or exclusive internal flow on CDU of thyroid FNs was considered indicative of malignancy. The overall sensitivity of CDU was 85% (95% confidence interval [CI], 74%-93%), with an overall specificity of 86% (95% CI, 82%-89%). The overall prevalence was 14.7%, and the positive and negative predictive values were 51% and 97%, respectively. The positive likelihood ratio was 6.07, and the negative likelihood ratio was 0.18.

CONCLUSIONS

Predominant internal flow seen on CDU is associated with malignancy of thyroid FNs. Absence of internal flow or predominantly peripheral flow indicates a low probability of thyroid FN malignancy.

[Epidemiology, pathophysiology, guideline-adjusted diagnostics, and treatment of thyroid nodules]

BACKGROUND

Clinically relevant thyroid carcinomas can be found in 5-6% of nodular goiters which undergo surgery. Moreover, multinodular goiters fre- quently contain hot areas. Therefore, efficient and rational methods for the differential diagnosis and decision are required to identify those nodules with an increased cancer risk or those which are hot among the many thyroid nodules.

METHODS

Description of a newly revised and further guidelines and consensus statements as well as selected literature search.

RESULTS

Already history, ultrasound and TSH (thyroid-stimulating hormone) determination do allow a first risk assessment for the further diagnostic work-up. Fine-needle biopsy (FNB) offers the best sensitivity and specificity for the distinction between benign and malignant thyroid nodules. The combination of several clinical and ultrasound criteria and laboratory determinations (calcitonin) can help with the selection of thyroid nodules with scintigraphically normal or decreased uptake > 1 cm for FNB. However, the efficiency of FNB requires sufficient training and experience of both the cytopathologist and the person performing FNB.

CONCLUSION

Whereas solitary thyroid nodules with a suspicion for malignancy should be referred to the surgeon, euthyroid thyroid nodules without clinical ultrasound or cytological indicators of malignancy may be followed up - possibly under medication -, if surgery is not indicated by local complaints, tracheal or mediastinal involvement.

The incidence of Hashimoto's disease in nodular goitre: the concordance in serological and cytological findings

OBJECTIVE

To determine the incidence of Hashimoto's disease in nodular goitre and to ascertain the degree of the concordance between serological and cytological findings.

METHODS

We retrospectively reviewed data from 188 patients who underwent a fine needle aspiration biopsy of the thyroid for uninodular or multinodular goitre with a documented serological level of antithyroid peroxidase (TPO) antibodies. AntiTPO antibodies were measured by immunochemiluminescent assay (Quest Diagnostics, Madison, NJ, USA).

RESULTS

The study cohort consisted of 170 female and 18 male patients with a mean (+/- SD) age of 47.8 +/- 14.9 years. AntiTPO antibodies were positive in 74 (39.36%) of the individuals and negative in 114 (60.63%). The cytodiagnoses were as follows: 5 (2.6%) cancerous, 18 (9.5%) suspicious, 12 (6.3%) inadequate, 92 (48.9%) benign and 61 (32.4%) consistent with chronic lymphocytic thyroiditis (CLT). For further analysis, we excluded all inadequate specimens. Based on the final sample of 176 patients, the sensitivity and specificity of antiTPO antibody test to detect CLT in nodular goitre were estimated to be 76.38% and 94.23% respectively. The prevalence of CLT in nodular goitre based on cytological criteria was (35.46%) compared with (31.97%) goitre based on positive antiTPO titres only.

CONCLUSION

There is a high degree of concordance between serological and cytological findings of CLT in people with nodular goitres. The high prevalence of CLT in nodular goitre justifies the use of antiTPO antibodies as part of the workup in this population.

Growing thyroid nodules with benign histology and RET rearrangement

Some benign thyroid nodules are stationary in size over time while others grow progressively, indicating that there is a broad individual variability within benign nodules. To date, it is very difficult to predict if a benign thyroid nodule will grow in size and which will be its trend over time. While BRAF(V600E) is a highly specific marker of thyroid cancer, RET rearrangements have been disclosed also in non malignant thyroid lesions and their biological significance is debated. We compared the clinical history of three histologically benign thyroid nodules harboring RET rearrangements with that of 6 benign nodules bearing wild type RET. The nodules negative for RET rearrangements were followed for 10 years by ultrasonographic evaluation, showing a slow, constant enlargement. Three patients with benign nodules diagnosed at FNAC, were followed for 11, 9 and 7 years by annual ultrasonographic evaluation. After several years of latency, the nodules had an unexpected and gradual increase in their dimensions, reaching a large final size. A second FNAC confirmed the previous cytologic diagnosis of benign lesion. Because of the increasing size of the nodules, the patients were advised to surgery. Before undergoing thyroidectomy, we performed molecular diagnostic tests that revealed the absence of BRAF(V600E) and the presence of RET/PTC-1 in one nodule and RET/PTC-3 in the two others. Despite the presence of this oncogene, the samples were histologically classified as benign hyperplastic nodules. These findings lead us to speculate that histologically benign hyperplastic thyroid nodules containing RET rearrangements might represent a subgroup of nodules with a rapid size increase.

Ultrasonographic evaluation of thyroid nodules: comparison of ultrasonographic, cytological, and histopathological findings

Thyroid ultrasonography (US) and fine needle aspiration biopsy (FNAB) are the most important tools in evaluating thyroid nodules. A total of 3,404 nodules in 2,082 cases referred to our clinic between 2005 and 2008 were analyzed retrospectively. Considering US features of nodules, risk factors predicting malignancy were: margin irregularity as the most important predictor, hypoechoic pattern and microcalcification (Odds ratios: 63.2, 13.3, 7.03, respectively). Cytologic results of the patients were as follows: 1,718 (82.5%) benign, 196 (9.4%) suspicious, 68 (3.3%) nondiagnostic, and 100 (4.8%) malignant. In histopathologic examination, we determined a malignancy rate of 7.59% (158/2082). We calculated the sensitivity of FNAB as 89.16%, specificity as 98.77%, positive predictive value as 96.10%, negative predictive value as 96.39%, and accuracy as 96.32%. In cytologic examination, the malignancy rate of subcentimetric (≤1 cm) nodules was higher than supracentimetric (>1 cm) nodules (5.1% vs. 1.5%, P = 0.001). In postoperative histopathologic examination, although the malignancy rate of subcentimetric nodules was higher than that of supracentimetric nodules, the difference was statistically insignificant (5.5%, 4.4%, respectively; P > 0.05). Cytologically diagnosed malignancy was detected in 4.5% of patients with multiple nodules, while it was present in 6% of patients with solitary nodule indicating no significant difference. However, postoperative histopathologic examination revealed a significantly higher malignancy rate in patients with solitary nodule compared to in patients with multiple nodules (11.7%, 6.5%; respectively, P < 0.001). The malignancy rate of patients operated for suspicious cytology was found to be 46.15%; for nondiagnostic cytology, it was 64.29%. In conclusion, ultrasonographically, hypoechoic pattern, microcalcification and margin irregularity of thyroid nodules are important features in determining the malignancy risk. The nodule size alone still remains inadequate to exclude malignancy risk.

99mTc-MIBI Imaging in the presurgical characterization of thyroid follicular neoplasms: relationship to multidrug resistance protein expression

Recently, thyroid (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) scintiscanning has been proposed in an attempt to preoperatively identify thyroid malignancies, but discrepant results have been reported for oncocytic lesions. The aim of this study was to investigate the usefulness of visual and semiquantitative analyses of (99m)Tc-MIBI scintigraphy for preoperatively characterizing thyroid nodules with indeterminate cytologic diagnoses, segregating in advance nononcocytic variants from those that are oncocytic. This study also aimed to analyze the relationship between (99m)Tc-MIBI images and P-glycoprotein (P-gp)/multidrug resistance-associated protein-1 (MRP1) immunohistochemical expression.

METHODS

Fifty-one consecutive patients with cold thyroid nodules cytologically diagnosed as nononcocytic or oncocytic follicular neoplasm were prospectively studied. Visual and semiquantitative (99m)Tc-MIBI scanning was performed and the diagnoses of the lesions were histologically proven by subsequent thyroidectomy. Immunohistochemical evaluation of P-gp and MRP1 was also performed on surgical samples.

RESULTS

Visual and semiquantitative (99m)Tc-MIBI scintiscans showed a low specificity in preoperatively discriminating malignant oncocytic lesions. In nononcocytic nodules, the semiquantitative method was more accurate than the visual (94.44% and 77.78%, respectively). P-gp protein expression was negative in all thyroid lesions, whereas apical plasma membrane MRP1 expression was found in 78% of the lesions with a negative (99m)Tc-MIBI retention index, compared with 11% of lesions with a positive retention index, correlating most strongly with a negative (99m)Tc-MIBI RI in those cases with strong MRP1 apical expression.

CONCLUSION

Semiquantitative (99m)Tc-MIBI scintigraphy is an adjunctive method to predict preoperatively the malignant behavior of nononcocytic follicular thyroid nodules indeterminate at fine-needle aspiration biopsy, with a potential impact on the definition of their clinical management. Moreover, the good correlation found between immunohistochemical apical expression of MRP1 and the scintigraphic findings supports the (99m)Tc-MIBI results and provides tissue information on the molecular mechanisms responsible for (99m)Tc-MIBI images in thyroid lesions.

A 30-year perspective on radioiodine therapy of benign nontoxic multinodular goiter

PURPOSE OF REVIEW

There is no consensus on the ideal treatment of patients with a benign nontoxic multinodular goiter. In some European countries, (131)I therapy has replaced surgery as the treatment of choice in these patients. Recombinant human thyrotropin (rhTSH) is a very potent stimulator of the thyroid gland and this review focuses on rhTSH-stimulated (131)I therapy.

RECENT FINDINGS

The concept of rhTSH-stimulated (131)I therapy has been tested in several trials during the last 8 years. With this treatment, the goiter reduction is improved by 35-55%, compared with (131)I therapy without rhTSH stimulation. RhTSH prestimulation is particularly beneficial in patients with very large goiters and in those with a low baseline thyroid (131)I uptake. In addition, this therapy facilitates tracheal decompression leading to improved respiratory function. RhTSH-stimulated (131)I therapy results in a higher rate of permanent hypothyroidism, whereas other side-effects are very modest when using a rhTSH dose of 0.1 mg or below.

SUMMARY

RhTSH-stimulated radioiodine therapy of benign nontoxic multinodular goiter is still an off-label use but several trials have shown that this treatment is significantly more effective than (131)I therapy without rhTSH. However, no trial has yet compared (131)I therapy and surgery head-to-head, and future trials should include evaluation of quality of life and cost.

Localized ablation of thyroid tissue by high-intensity focused ultrasound: improvement of noninvasive tissue necrosis methods

BACKGROUND

Although thyroid nodules are frequently detected in patients during routine examinations, such nodules are rarely malignant. Surgical treatment of nodules is controversial because of the possible complications associated with surgery, and there is an unmet need for a minimally invasive alternative. We previously reported on a high-intensity focused ultrasound (HIFU) device that induced necrosis in ewe thyroids. This complementary study on 27 ewes evaluated the use of the device to produce thyroid lesions, characterized the HIFU-induced lesions on the thyroid and surrounding structures, and evaluated the safety and reproducibility of the method.

METHODS

A spherical 3-MHz transducer that was coupled to a 5-MHz linear array ultrasound imaging probe was used to generate powerful acoustic waves to destroy thyroid tissue. Three series of experiments were conducted: thyroid lesion experiments (10 ewes), safety experiments (4 ewes), and reproducibility experiments (13 ewes). After fixation of the ewe's neck, tissue lesions were examined both macroscopically and histologically.

RESULTS

First, individual pulsed acoustical waves were used to induce lesions in 19 thyroid lobes. In most lesions, there was coagulative necrosis that was replaced later by fibrosis. Macroscopic examination of adjacent organs revealed skin lesions and muscle injuries. A second series of experiments evaluated the consequences of HIFU pulsed waves on structures surrounding the thyroid to better characterize possible side effects of HIFU. Firings at the periphery of eight lobes revealed macroscopic lesions in the trachea of one ewe and superficial esophagus lesions in three ewes. The recurrent nerves were damaged bilaterally in one ewe that died from dysphagia 3 days after HIFU. Four ewes were found to have muscle injuries, but no skin lesions were observed. A third series of experiments evaluated the reproducibility of a HIFU prototype designed specifically for human use. Thyroid lesions were obtained in 25 of the 26 treated lobes. No damage to the nerves, trachea, esophagus, or muscles was observed. About 3 of the 13 ewes had superficial skin burns.

CONCLUSION

The results obtained in the ewe model show that thyroid lesions with a defined volume can be induced safely and suggest that the HIFU device is now ready for evaluation in humans.

Therapy: a new nonsurgical therapy option for benign thyroid nodules?

Despite the increasing implementation of iodization programs, benign nodular thyroid disease will remain a prevalent therapeutic concern for decades. recent research suggests that nonsurgical therapy, including radioactive iodine, radiofrequency thermal ablation and percutaneous laser ablation, might have a role in the treatment of symptomatic patients.

High prevalence of side effects after recombinant human thyrotropin-stimulated radioiodine treatment with 30 mCi in patients with multinodular goiter and subclinical/clinical hyperthyroidism

BACKGROUND

Treatment of multinodular goiters (MNGs) is highly controversial. Radioiodine (RAI) therapy is a nonsurgical alternative for the elderly who decline surgery. Recently, recombinant human thyrotropin (rhTSH) has been used to augment RAI uptake and distribution. In this study, we determined the outcome of 30 mCi RAI preceded by rhTSH (0.1 mg) in euthyroid (EU) and hyperthyroid (subclinical/clinical) patients with large MNGs.

METHODS

This was a prospective cohort study. Forty-two patients (age, 43-80 years) with MNGs were treated with 30 mCi RAI after stimulation with 0.1 mg of rhTSH. Patients were divided into three groups, according to thyroid function: EU (n = 18), subclinically hyperthyroid (SC-H, n = 18), and clinically hyperthyroid (C-H, n = 6). All patients underwent a 90-day low-iodine diet before treatment, and those with clinical hyperthyroidism received methimazole 10 mg daily for 30 days. Serum TSH, free thyroxine (FT4), total triiodothyronine (TT3), and thyroglobulin were measured at baseline and at 24, 48, 72, 168 hours, and 1, 3, 6, 9, 12, 18, 24, and 36 months after therapy. Thyroid volume was assessed by computed tomography at baseline and every 6 months.

RESULTS

Patients had high iodine urinary excretion (308 +/- 108 microg I/L) at baseline. TSH levels at baseline were within the normal range (1.5 +/- 0.7 microU/mL) in the EU group and suppressed (<0.3 microU/mL) in the SC-H and C-H groups. After rhTSH, serum TSH peaked at 24 hours reaching 12.4 +/- 5.85 microU/mL. After RAI administration, patients in both hyperthyroid groups had a higher increase in FT4 and TT3 compared with those in the EU group (p < 0.001). Thyroglobulin levels increased equally in all three groups until day 7. Thyroid volume decreased significantly in all patients. Side effects were more common in the SC-H and C-H groups (31.4% and 60.4%, respectively) compared with EU patients (17.8%). Permanent hypothyroidism was more prevalent in the EU group (50%) compared with the SC-H (11%) and C-H (16.6%) groups.

CONCLUSIONS

Patients with MNG may have subclinical and clinical nonautoimmune iodine-induced hyperthyroidism. Despite a low-iodine diet and therapy with methimazole, hyperthyroid patients have a significantly higher increase in FT4 and TT3 levels after RAI ablation. This can lead to important side effects related mostly to the cardiac system. We strongly advise that patients with SC-H and C-H be adequately treated with methimazole and low-iodine diet aiming to normalize their hyperthyroid condition before rhTSH-stimulated treatment with RAI.

Radioiodine therapy in non-toxic multinodular goitre. The possibility of effect-amplification with recombinant human TSH (rhTSH)

There is no consensus regarding the optimum treatment of benign non-toxic goitre. L-thyroxine suppressive therapy is widely used, but there is poor evidence of its efficacy, and it may have serious adverse effects on health. Surgery is first choice in large goitres or if malignancy is suspected. 131I therapy results in a one-year goitre reduction of around 40% in multinodular goitres, usually with a high degree of patient satisfaction and improvement of the inspiratory capacity. The effect is attenuated with increasing goitre size. The risk of hypothyroidism is 22-58% within 5-8 years. A sufficient thyroid 131I uptake is mandatory for 131I therapy to be feasible and pre-stimulation with recombinant human TSH (rhTSH) increases this considerably. This leads to an increased absorbed thyroid dose by approx.75%, mainly in those patients with the lowest thyroid 131I uptake, and a more homogeneous intrathyroidal isotope distribution. Pre-stimulation with even a small dose of rhTSH seems to allow a reduction of the 131I activity while still achieving a mean goitre reduction of approximately 40% within a year. A significantly lower extrathyroidal radiation is achieved by this approach. With an unchanged 131I activity, rhTSH pre-stimulation improves the goitre reduction by 30-50%. However, this is at the expense of a higher rate of hypothyroidism, cervical pain and transient thyrotoxicosis. Of particular concern is the observation made in healthy persons, that rhTSH results in a transient average thyroid volume increase of 35%. A similar goitre swelling may cause problems in susceptible patients during rhTSH-augmented 131I therapy. Thus, this concept still needs a closer evaluation before routine use.

Long-term outcome of low-activity radioiodine administration preceded by adjuvant recombinant human TSH pretreatment in elderly subjects with multinodular goiter

Background

Large multinodular goiter (MNG) in elderly people is a common finding which can require intervention. The long-term effect of radioiodine therapy on thyroid volume (TV) and function after recombinant human (rh) TSH pre-treatment was evaluated.

Methods

After baseline evaluation, 40 subjects over 60 years old with a large MNG were treated with ¹³¹I up to the activity of 600 MBq. Nineteen patients were pretreated with rhTSH (0.1 mg on 2 consecutive days; group 1) while 21 subjects underwent treatment without rhTSH pretreatment (group 2). TV was monitored every 6–12 months by ultrasonography. The median follow-up period was 36 months.

Results

At the baseline, the groups matched in terms of TV, 24-h radioiodine uptake (RAIU), urinary iodine and neck complaints. The number of subjects pretreated with anti-thyroid drugs was significantly (P = 0.01) greater in group 2 than in group 1; TSH was more suppressed (P = 0.003) and f-T3 was more elevated (P = 0.005) in group 2 than in group 1 patients. RhTSH increased 24-h RAIU in group 1 up to the baseline level observed in group 2. The ¹³¹I activity administered was similar in both groups. Adverse events were slight and similar in both groups. A permanent post-radioiodine toxic condition was reported only in 2 patients in group 2. After radioiodine therapy, hypothyroidism was observed in significantly more group 1 patients than group 2 patients (P = 0.002). While TV was reduced in both groups, the percentage TV reduction recorded at the last examination was significantly higher (P = 0.03) in group 1 than in group 2. MNG-related complaints were significantly reduced in both group 1 (P = 0.0001 vs baseline) and group 2 (P = 0.001) patients.

Conclusion

Low radioiodine activities after pretreatment with low-dosage rhTSH are able to reduce TV and improve MNG-related symptoms in elderly subjects.

Juvenile thyroid malignancy

Thyroid malignancy is an uncommon tumor of the pediatric population. Patients can present with asymptomatic thyroid nodule and it requires thorough work up to rule out the malignancy. Radiological and pathological procedures are a standard part of the management. A 10-year-old girl had asymptomatic thyroid nodule; the cytological examination and the frozen section and final histology of the nodule was different each time. The girl had to undergo total thyroidectomy on the basis of histology of the nodule which was well differentiated papillary carcinoma of thyroid and is under regular follow-up for last two years on thyroid supplementation.

Time to reconsider nonsurgical therapy of benign non-toxic multinodular goitre: focus on recombinant human TSH augmented radioiodine therapy

The treatment of benign multinodular goitre (MNG) is controversial, but surgery is recommended in large compressive goitres. While some patients decline surgery others may have contraindications due to comorbidity, since MNG is prevalent in the elderly. Therefore, non-surgical treatment alternatives are needed. Until recently, levothyroxine therapy was the preferred non-surgical alternative, but due to low efficacy and potential side-effects, it is not recommended for routine use in recent international guidelines. Conventional radioiodine ((131)I) therapy has been used for two decades as an effective and safe alternative to surgery in the treatment of symptomatic non-toxic MNG. Since much higher activities of (131)I are employed when treating non-toxic rather than toxic MNG, there has been reluctance in many countries to use this treatment modality. Frequently, the (131)I -uptake in a non-toxic MNG is low, which makes (131)I therapy less feasible. Another challenge is the negative correlation between the initial goitre size and goitre volume reduction (GVR). With its ability to more than double the thyroid (131)I-uptake, recombinant human TSH (rhTSH) increases the absorbed radiation dose and thus enhances the GVR by 35-56% at the expense of up to fivefold higher rate of permanent hypothyroidism. An alternative strategy is to reduce the administered (131)I-activity with a factor corresponding to the rhTSH induced increase in (131)I-uptake. Hereby, the extrathyroidal irradiation can be reduced without compromising efficacy. Thus, although in its infancy, and still experimental, rhTSH-augmented (131)I therapy may profoundly alter the non-surgical treatment of benign non-toxic MNG.

Therapy of large multinodular goitre using repeated doses of radioiodine

OBJECTIVE

To evaluate the efficacy of radioiodine therapy using I in a group of patients with large multinodular goitre (LMG).

METHODS

The study was carried out in patients with goitre volume greater than 100 cm and in patients with LMG who were disqualified from surgery. The study included 34 female participants (age range: 62-84 years) with LMG: 26 patients were hyperthyroid and eight patients had a nontoxic goitre. The patients were treated with 800 MBq of radioiodine administered four times at 3-month intervals (total activity of 3.2 GBq). Before each therapy course, serum thyrotropin, free thyroxin, free triiodothyronine and antithyroid antibodies were measured, ultrasonography and thyroid scan were performed. Patients were followed up for a minimum of 24 months. Fine-needle biopsy was done before qualification to the study.

RESULTS

Before therapy, median thyroid volume was 145 cm. It decreased during therapy to 65-76 cm after 12 months and to 50-62 cm after 24 months. After 24 months, 60% of patients were euthyroid and 40% of patients were hypothyroid. During therapy, significant increases in TSHRAb, TPOAb and TgAb levels were observed. No correlation between the levels of antithyroid antibodies, radioiodine uptake, reduction of goitre volume and hormonal status was found.

CONCLUSION

In most cases of LMG, repeated administration of radioiodine is safe and effective. The highest response of the thyroid volume is observed after the first course of treatment. On account of a high incidence of hypothyroidism, the patients should be monitored during and after therapy.

No link between X chromosome inactivation pattern and simple goiter in females: evidence from a twin study

BACKGROUND

Simple goiter (SG) comprises diffuse (DG) and nodular (NG) benign nonautoimmune nontoxic goiter. In nonendemic goiter areas, the ratio of females to males may exceed 5:1, indicating that gender and/or sex hormones may play a role in the etiology of SG in these areas. Theoretically, as shown for autoimmune thyroid disease, X chromosome inactivation (XCI) and resultant tissue chimerism could offer a novel explanation for the female preponderance of SG. To examine whether skewed XCI is associated with SG, we first compared XCI in 71 twin individuals with SG with that in 142 unrelated healthy control twin individuals, and then performed a within-pair comparison of XCI in 48 twin pairs discordant for SG.

METHODS

DNA was extracted from peripheral blood cells. XCI analysis was performed by predigestion of DNA using the methylation-sensitive enzyme Hpall, followed by polymerase chain reaction of the polymorphic CAG repeat of the androgen receptor gene. A polymerase chain reaction product is obtained from the inactive X chromosome only. The XCI pattern was classified as skewed when 80% or more of the cells preferentially inactivated the same X chromosome. Twin zygosity was established by DNA fingerprinting.

RESULTS

The frequency of skewed XCI in female twins with SG, DG, and NG was 11% (8/71), 13% (6/46), and 8% (2/25), respectively, which was not significantly different from the prevalences in the corresponding control populations, 14% (20/142, p = 0.56), 14% (13/92, p = 1.00), and 14% (7/50, p = 0.71), respectively. Essentially, similar results were obtained when comparing the prevalence of skewed XCI in twin pairs discordant for SG (48 pairs), DG (30 pairs), and NG (18 pairs).

CONCLUSION

In a sample of Danish female twins, we did not find evidence for involvement of skewed XCI in the etiology or the female preponderance of SG.

Does near total thyroidectomy offer advantage over total thyroidectomy in terms of postoperative hypocalcemia?

Total thyroidectomy (TT) has emerged as a surgical option in the surgical treatment of patients with multinodular goiter. TT carries potential risk to all parathyroid glands and both recurrent laryngeal nerve. The aims of this study are to evaluate the difference between serum calcium levels before and after total and near total thyroidectomy and to compare the rate of postoperative hypocalcemia according to surgical procedures. This prospective study included 143 consecutive patients undergoing surgical therapy for non-toxic multinodular goiter. Patients were randomly assigned to surgical procedures. Patients in group 1 (n=75) performed TT, and patients in group 2 (n=68) performed near total thyroidectomy (NTT). The difference between serum calcium levels and percentage decrease in serum calcium levels before and after thyroidectomy were calculated. TT had a 33-fold (OR: 33.1; 95% CI: 7.5-145.02) increased risk for hypocalcemia. Moreover, TT had a 8-fold (OR: 8.09; 95% CI: 3-21.4) and a 27-fold (OR: 27.9; 95% CI: 3.5-219.6) higher risk than NTT for moderate and severe percentage decreases in serum calcium level, respectively. NTT can offer an advantage over TT in terms of postoperative hypocalcemia in the patients with benign multinodular goiter.

The majority of Danish nontoxic goitre patients are ineligible for Levothyroxine suppressive therapy

OBJECTIVE

Levothyroxine suppressive therapy (LT4-therapy), aimed at shrinking thyroid nodules is controversial. Despite evidence of limited effect and long-term side-effects, questionnaire surveys indicate widespread use. Our aim was to determine, in consecutive nontoxic goitre patients, the proportion ineligible for LT4-therapy. Exclusion criteria were set up in agreement with recent guidelines.

SETTING

Secondary/tertiary referral centre at University Clinic.

SUBJECTS AND METHODS

During 1997-2001, 822 patients were referred to our endocrine unit on suspicion of nontoxic goitre. Patients were evaluated clinically including fine needle aspiration biopsy, thyroid scintigraphy and ultrasound. Seven-hundred and forty-five patients (627 women and 118 men; median age 47 years, range 11-90) were potential candidates for LT4-therapy. Based on guidelines we defined conditions where LT4-therapy is contraindicated. Exclusion criteria included (1) Serum TSH < 1.0 mIU/l, (2) Post-menopausal status, or males older than 60 years, (3) Thyroid volume above 100 ml, (4) Intrathoracic goitre, (5) Clinical suspicion of malignancy, (6) Dominant thyroid cyst, (7) Nondiagnostic FNA, (8) Previous ineffective LT4-therapy, (9) Elevated serum calcitonin, (10) Osteoporosis or cardiovascular disease.

RESULTS

Of patients 84% were ineligible for LT4-therapy. In diffuse goitre (n = 35) 63%, in uninodular goitre (n = 320) 77% and in multinodular goitre (n = 390) 91% were ineligible. Main ineligibility reasons were a low serum TSH, post-menopausal status, a large goitre or clinical suspicion of malignancy.

CONCLUSION

The vast majority of consecutive Danish nontoxic goitre patients (84%) were ineligible for LT4-therapy. Due to low efficacy and potential long-term adverse effects on the skeleton and cardiovascular system we strongly advocate against LT4-therapy for nontoxic goitre.

Decision analysis of discordant thyroid nodule biopsy guideline criteria

CONTEXT

Recently published guidelines are discordant regarding diagnostic approaches to small (10-14 mm) thyroid nodules.

OBJECTIVE

The objective of the study was to explore the relative desirability of alternative diagnostic approaches to small thyroid nodules using decision analysis.

DESIGN

Four diagnostic approaches to a 10- to 14-mm thyroid nodule are modeled: 1) observation only, consistent with American Thyroid Association guidelines; 2) routine fine-needle aspiration biopsy (FNAB), an approach traditionally chosen by many endocrinologists and consistent with American Thyroid Association guidelines; 3) FNAB only when microcalcifications are present, as recommended by Society of Radiologists in Ultrasound guidelines; and 4) FNAB only when the nodule is hypoechoic and has at least one other ultrasonographic risk factor, as endorsed by American Association of Clinical Endocrinologists guidelines.

MAIN OUTCOME MEASURES

Measures included expected values; a priori likelihoods of prespecified outcomes; and two-way sensitivity analyses based on the utility of observation only in the setting of thyroid cancer and thyroid surgery for benign, asymptomatic thyroid disease.

RESULTS

Expected values (EVs) were similar among decision alternatives modeling Society of Radiologists in Ultrasound guidelines, American Association of Clinical Endocrinologists guidelines, and routine observation (EVs from 0.912 to 0.927). Routine FNAB had the lowest EV (0.757-0.861), primarily related to a high a priori likelihood of having surgery for a benign nodule.

CONCLUSIONS

As a general approach to 10- to 14-mm thyroid nodules, routine FNAB appears to be the least desirable. This analysis offers additional data that physicians can use when choosing diagnostic approaches to small thyroid nodules based on perceived risks of delayed cancer diagnosis and unnecessary thyroid surgery.

The odyssey of nontoxic nodular goiter (NTNG) in Greece under suppression therapy, and after improvement of iodine deficiency

BACKGROUND

Nontoxic nodular goiter (NTNG) is common in endemic goiter regions. Thyroxine (T4) is often used to treat NTNG. There is little information regarding T4 treatment in regions that have recently become iodine sufficient. We studied the effect of T4 treatment on thyroid function tests in southwestern Greece (SWG), a recently iodine-sufficient area.

METHODS

We studied 827 residents of SWG (group A) to determine goiter prevalence, thyroid function, and urinary iodine concentration (UIC). Group B: 385 consecutive patients with thyroid dysfunction. Of these, 89 had NTNG and followed for 10 years on T4 treatment, and 296 had hyperthyroidism. Group C: 29 patients with NTNG, treated with triiodothyronine (T3) 50 mug/day and followed for 6 months. Measurements included serum T4 and 24-hour radioactive iodine uptake (RAIU) before and at the end of T3 administration.

RESULTS

The median UIC in group A was 114 microg/L. In group B (89 patients), the incidence of newly diagnosed hyperthyroidism was 5-7% per year with a cumulative percentage of 33% at the 10th year. The initial thyrotropin (TSH) was lower (0.78 +/- 0.51 mIU/L) in those who developed thyrotoxicosis compared to those who remained euthyroid (1.17 +/- 0.74 mIU/L) (p < 0.05). In 296 thyrotoxic patients, the incidence of autoimmune hyperthyroidism and toxic multi-nodular goiter (TMNG) was similar. In group C, 10/29 patients remained euthyroid and the 24-hour RAIU decreased by 49% during T3 treatment. Similarly, serum T4 decreased by 49%. In the remaining patients who developed hyperthyroidism, 24-hour RAIU and T4 were decreased by 19% and 22%, respectively.

CONCLUSIONS

In SWG, a recently iodine-sufficient region, the risk of developing hyperthyroidism in patients with NTNG after administration of 100-150 microg T4 is relatively high in those whose serum TSH before T4 treatment is in the lower normal range. Therefore, T4 treatment should be avoided in these patients.

[What are the alternative criteria for fine needle aspiration biopsy of a thyroid nodule?]

OBJECTIVES

To identify the clinical and paraclinical factors of thyroid nodule malignancy (in absence of ultrasound-guided fine needle aspiration biopsy data).

PATIENTS AND METHODS

This retrospective study was conducted on a cohort of 282 patients admitted for management of a thyroid nodule disease. All patients had undergone surgery and the specimen had been analyzed anatomically and pathologically. Forty-four patients had malignant disease. Epidemiological, clinical, and paraclinical data, as well as the anatomical and pathological characteristics of the specimen were collected for each patient.

RESULTS

We showed that the epidemiological data (sex and age), the nodule's characteristics (consistency, irregularities of the edges and fixity to underlying structures, and size), the presence of adenopathies, signs of compression, and the presence of calcifications were the predictability criteria of malignant disease. However, the scintigraphic aspect, the echostructure, and the hormonal status were not significant.

CONCLUSION

This study underscores that a relevant clinical and paraclinical analysis remains highly contributive in the presurgical identification of factors predictive of malignancy of a thyroid nodule, notably in countries where technological tools are not always available.

Dyspnea and stridor due to multinodular goiter in an obese woman

Substernal multinodular goiter is a common entity that may cause life threatening pressure symptoms. We report the case of a patient with tracheal stenosis due to multinodular goiter and discuss various treatment options.

Bone mineral density in end-stage renal disease patients: association with wasting, cardiovascular disease and mortality

BACKGROUND

Bone and mineral disorders may contribute to extraosseous ossifications and cardiovascular disease (CVD) in end-stage renal disease (ESRD) patients. We have investigated the relationship between bone mineral density (BMD) and inflammation, wasting, CVD and mortality in ESRD patients.

METHODS

BMD (dual energy X-ray absorptiometry) and biochemical, nutritional and inflammatory markers were assessed in 277 incident ESRD patients (GFR 7.1 +/- 0.2 ml/min) who were then followed prospectively for a mean of 27 (range 1-60) months. Carotid plaques were determined in 103 patients.

RESULTS

Patients with carotid plaques, clinical manifestation of CVD and wasting (assessed by subjective global assessment) had significantly lower BMD than their counterparts. Low BMD was associated with high all-cause and cardiovascular mortality. Even after adjustment for several confounders and risk factors, all-cause (HR = 2.1, CI: 1.1-3.9, p = 0.02) and cardiovascular (HR = 2.8, CI: 1.2-6.3, p = 0.02) mortality remained significantly associated with low BMD.

CONCLUSIONS

Low BMD is associated with wasting and CVD, and is an independent predictor of all-cause and cardiovascular mortality in ESRD patients.

Quantification of thyroid volume using 3-D ultrasound imaging

Ultrasound (US) is among the most popular diagnostic techniques today. It is non-invasive, fast, comparably cheap, and does not require ionizing radiation. US is commonly used to examine the size, and structure of the thyroid gland. In clinical routine, thyroid imaging is usually performed by means of 2-D US. Conventional approaches for measuring the volume of the thyroid gland or its nodules may therefore be inaccurate due to the lack of 3-D information. This work reports a semi-automatic segmentation approach for the classification, and analysis of the thyroid gland based on 3-D US data. The images are scanned in 3-D, pre-processed, and segmented. Several pre-processing methods, and an extension of a commonly used geodesic active contour level set formulation are discussed in detail. The results obtained by this approach are compared to manual interactive segmentations by a medical expert in five representative patients. Our work proposes a novel framework for the volumetric quantification of thyroid gland lobes, which may also be expanded to other parenchymatous organs.

An outline concerning the potential use of recombinant human thyrotropin for improving radioiodine therapy of multinodular goiter

Radioiodine ((131)I) treatment for nontoxic and toxic multinodular goiter (MNG) is an alternative therapeutic procedure used especially for patients with contraindication for surgery. Several studies have been conducted in recent years assessing the use of recombinant human TSH (rhTSH) in increasing (131)I uptake in MNGs. This procedure also decreases the activity level of the administered (131)I, changes the distribution of (131)I in the thyroid, lowers the absorption dose, and dramatically reduces the volume of the goiter (50-75% of the baseline volume). A major disadvantage, however, is the induction of hypothyroidism in a relatively large number of patients. A transient increase in thyroid volume and tenderness was noted in the first week of treatment. Also a short period (2-4 weeks) of hyperthyroidism was observed in most patients with potential consequences particularly for the elderly. Still, there has been no evidence to date that the adverse effects outweigh the positive results of using rhTSH. The use of rhTSH in benign goiter disease has not yet been approved worldwide, but its positive activity in MNG is remarkable and promising.