Levothyroxine and potassium iodide are both effective in treating benign solitary solid cold nodules of the thyroid

Synthesis of chiral α-substituted α-amino acid and amine derivatives through Ni-catalyzed asymmetric hydrogenation

Highly efficient Ni-catalyzed asymmetric hydrogenation of cyclic N-sulfonyl ketimino esters was, for the first time, successfully developed, providing various chiral α-monosubstituted α-amino acid derivatives with excellent results (97-99% yields, 90 to >99% ee). Cyclic N-sulfonyl ketimines were also hydrogenated well to afford chiral amine derivatives with 98-99% yields and 97 to >99% ee. The gram-scale asymmetric hydrogenation was performed well with 85% yield and 99% ee using only 0.2 mol% catalyst.

The effect of suppressive thyroxine therapy in nodular goiter in postmenopausal women and 2 year's bone mineral density change

The efficacy of thyroxine suppressive therapy in reducing nodular growth and its effect to bone mineral density (BMD) in postmenopausal women is still debated. This study aimed to evaluate the therapeutic effect of thyroxine and its influence on BMD. Postmenopausal women with nodular or multinodular goiter during 2013-2015 at Chang Gung Memorial Hospital were enrolled and retrospectively traced back to the first date of visit or treatment. Ninety-four eligible patients were enrolled, of whom 45 were thyroxine-treated (LT-4 group) and 49 were treatment-naïve (control group). Data, including volume of nodules, were analyzed retrospectively. BMD was measured in each LT-4 group patient since the year of enrollment. Nodular volumes were reduced in both LT-4 (from 4.89 ± 4.46 to 4.10 ± 4.57 mL, p = 0.033) and control group (3.48 ± 4.36 to 3.09 ± 2.88 mL, p = 0.239) at initial 2-year follow-up. Nodular volume in LT-4 group increased insignificantly (from 4.89 ± 4.46 to 4.91 ± 5.40 mL, p = 0.711) at the end of 7-year follow-up. The best cut-off predictive nodular volume that may have responded to thyroxine is 2.6 mL (AUC, 0.740; sensitivity, 0.750; specificity, 0.733) during first 2 year. Lumbar spine, total hip and femoral neck BMD were not significantly changed during 2 year's thyroxine suppression therapy. In conclusion, thyroxine suppressive therapy in postmenopausal women had significant reduction in nodule volume at initial 2 years of treatment, especially in volume larger than 2.6 mL. Prolonged thyroxine treatment did not benefit nodular size reduction and may affect BMD minimally in postmenopausal women.

Radiofrequency ablation for benign thyroid nodules

Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

Efficacy of Thyroid Hormone Suppression for Benign Thyroid Nodules: Meta-Analysis of Randomized Trials

OBJECTIVE: To determine the efficacy of thyroid hormone suppressive therapy (THST) to decrease benign thyroid nodule volume.

DESIGN: Meta-analysis.

METHODS: Systematic search using electronic databases (PubMed, Medline, Cochrane Library) through August 2004, paper review, and contacting experts and drug manufacturers. Only randomized controlled studies of THST vs no treatment or placebo, for reduction of benign thyroid nodule volume, were included. Exclusion criteria were: >6-month treatment, lack of ultrasound volume measurement, and region of endemic goiter. Primary outcome was clinically relevant nodule volume reduction (>50%), with a random effects model (RevMan4.2).

RESULTS: Nine randomized trials were included (609 subjects). Subjects were 88% more likely to experience >50% nodule volume reduction with THST than placebo or no treatment (relative risk = 1.88; 95% CI = 1.18-3.01; P = 0.008). However, 8 subjects must be subjected to the risk of cardiac and skeletal side effects from THST, for one to benefit from therapy (number needed to treat = 8, risk difference = 0.13; 95% CI = 0.06-0.19; P = 0.0003). Sensitivity analysis reveals that 15 null studies would have to have been missed to reverse statistical significance (fail-safe N = 15). Review of the only study with long-term treatment (5 years) suggests no significant difference in nodule volume reduction between THST and placebo. Further, studies with follow-up after THST withdrawal demonstrate rapid increase in thyroid nodule and goiter volumes.

CONCLUSION: THST appears more likely than placebo or no treatment to significantly reduce benign thyroid nodule volume, but long-term treatment may be less effective and regrowth is likely following cessation of therapy. Given the risks of THST, routine use is not recommended for benign nodules.

Evolution of benign thyroid nodules under levothyroxine non-suppressive therapy

BACKGROUND

Non-suppressive or partially suppressive L-T4 treatment demonstrated to be effective in reducing the volume of the nodules. However, studies with long follow-up are lacking and significant controversy exists regarding the efficacy of non-suppressive L-T4 treatment in benign nodular goiter.

AIM

The goal of this study was to determine the evolution of thyroid nodules in subjects treated with a non-suppressive levothyroxine (L-T4) dose, compared to untreated subjects.

DESIGN AND PATIENTS

We followed for a period of 1-9 years the thyroid nodule size in 356 female patients in the age range 19-45 at study entry, of which 201 untreated (Group 0) and 165 treated with a non-suppressive L-T4 dose (Group L-T4).

MEASUREMENTS

We determined the volume of thyroid nodules by ultrasonography.

RESULTS

The initial mean nodule volume in Group 0 and Group L-T4 was 3.91 ± 6.87 and 4.01 ± 7.35 mL, respectively. Nodule volume increase was inversely correlated to the initial volume. The final volume was slightly higher in untreated than in L-T4 treated subjects (5.37 ± 8.49 and 4.39 ± 6.72 mL). In both groups, the mean of annual fold increase of nodule volume was inversely correlated with the follow-up duration (P < 0.0046), indicating a slower growth as time advances. In the subjects treated with L-T4, the mean annual increase of nodule volume was significantly minor compared to untreated subjects. Concomitant nodules in ten multinodular goiters exhibited totally independent evolution, demonstrating that intranodular factors are more important for the nodule behavior than extra nodular factors.

CONCLUSIONS

Our study demonstrates that the growth of benign thyroid nodules is inversely correlated to their size, benign nodules naturally growth slowly as time advances, and that a chronic treatment with L-T4 at a non-TSH-suppressive dose significantly reduces their growth.

Levothyroxine or minimally invasive therapies for benign thyroid nodules

BACKGROUND

Thyroid nodules (TN) are common in the adult population. Some physicians use suppressive levothyroxine (LT4) therapy to achieve a reduction in the number and volume of TN. In addition, minimally invasive treatments, such as percutaneous ethanol injection (PEI) sclerotherapy, laser photocoagulation (LP), and microwave (MW), radiofrequency (RF) and high-intensity focused ultrasound (HIFU) ablation, have been proposed, especially for pressure symptoms and cosmetic complaints, as an alternative to surgery. However, the risk to benefit ratio of all treatments for benign TN is currently unknown.

OBJECTIVES

To assess the effects of LT4 or minimally invasive therapies (PEI, LP, and RF/HIFU/MW ablation) on benign TN.

SEARCH METHODS

We identified studies from computerised searches of The Cochrane Library, MEDLINE, EMBASE and LILACS (all performed up to April 2014). We also searched trial registers, examined reference lists of included randomised controlled trials (RCTs) and systematic reviews, and contacted study authors.

SELECTION CRITERIA

We included studies if they were RCTs of LT4, PEI, LP, RF, HIFU or MW therapy in participants with an established diagnosis of benign TN. We excluded trials investigating the prevention of recurrence of thyroid disease after surgery, irradiation or treatment with radioiodine.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, assessed studies for risk of bias and evaluated overall study quality utilising the GRADE instrument. We assessed the statistical heterogeneity of included studies by visually inspecting forest plots and quantifying the diversity using the I² statistic. We synthesised data using random-effects model meta-analysis or descriptive analysis, as appropriate.

MAIN RESULTS

Thirty-one studies randomised 2952 outpatients to investigate the effects of different therapies on benign TN. Studies on LT4, PEI, LP and RF ablation therapy randomised 2083, 607, 192 and 70 participants, respectively. We found no RCTs of HIFU or MW ablation therapy in benign TN. The duration of treatment varied according to the applied therapies: up to five years for LT4 and one to three PEI ablations, one to three LP sessions and one or two RF sessions. Median follow-up was 12 months for LT4 and six months for minimally invasive therapies. Evidence was of low-to-moderate quality, and risk of performance and detection bias for subjective outcomes was high in most trials.No study evaluated all-cause mortality or health-related quality of life. Only one LT4 study provided some data on the development of thyroid cancer, reporting no abnormal cytological findings. One LP study provided limited information on costs of treatment.LT4 compared with no treatment or placebo was associated with a nodule volume reduction of 50% or more in 16% compared with 10% of participants after 6 to 24 months of follow-up (risk ratio (RR) 1.57 (95% confidence interval (CI) 1.04 to 2.38); P = 0.03; 958 participants; 10 studies; moderate-quality evidence). Pressure symptoms or cosmetic complaints were not investigated in LT4 studies. LT4 therapy was generally well tolerated: three studies provided quantitative data on signs and symptoms of hyperthyroidism, which were observed in 25% of LT4-treated versus 7% of placebo-treated participants at 12 to 18 months of follow-up (269 participants; 3 trials; low-quality evidence).PEI compared with cyst aspiration only was associated with a nodule volume reduction of 50% or more in 83% compared with 44% of participants after 1 to 24 months of follow-up (RR 1.83 (95% CI 1.32 to 2.54); P = 0.0003; 105 participants; 3 studies; low-quality evidence). Improvements in neck compression symptoms after 6 to 12 months of follow-up were seen in 78% of participants receiving PEI versus 38% of those in comparator groups. No reliable summary effect estimate could be established, RR ranged from 1.0 to 3.06 in favour of PEI (370 participants; 3 trials; low-quality evidence). In all trials, participants experienced periprocedural cervical tenderness and light-to-moderate pain usually lasting from minutes to several hours. As a result of the PEI procedure, 26% of participants reported slight-to-moderate pain compared with 12% of those receiving cyst aspiration only (RR 1.78 (95% CI 0.62 to 5.12); P = 0.28; 104 participants; 3 studies; low-quality evidence).One study comparing LP with LT4 showed a nodule volume reduction of 50% or more in favour of LP after 12 months of follow-up in 33% of LP participants versus 0% of LT4 participants, respectively (62 participants; 1 trial; low-quality evidence). A total of 82% of LP-treated versus 0% of untreated participants showed improvements in pressure symptoms after 6 to 12 months of follow-up (RR 26.65 (95% CI 5.47 to 129.72); P < 0.0001; 92 participants; 3 trials; low-quality evidence). Around 20% of LP-treated participants reported light-to-moderate cervical pain lasting 48 hours or more (97 participants; 3 trials; low-quality evidence).One trial with 40 participants, comparing RF with no treatment, resulted in a mean nodule volume reduction of 76% in the RF group compared with 0% of those in the no-treatment group at six months of follow-up (low-quality evidence). These RF-treated participants had fewer pressure symptoms and cosmetic complaints after 12 months of follow-up compared with untreated participants (a 2.8 decrease versus a 1.1 increase on a six-point scale, respectively, with higher values indicating more severe symptoms; low-quality evidence). All participants complained of pain and discomfort during RF, which disappeared when the energy was reduced or turned off (low-quality evidence).

AUTHORS' CONCLUSIONS

No study evaluated all-cause mortality, health-related quality of life or provided systematic data on the development of thyroid cancer. Longest follow-up was five years and median follow-up was 12 months. Nodule volume reductions were achieved by PEI, LP and RF, and to a lesser extent, by LT4. However, the clinical relevance of this outcome measure is doubtful. PEI, LP and RF led to improvements in pressure symptoms and cosmetic complaints. Adverse events such as light-to-moderate periprocedural pain were seen after PEI, LP and RF. Future studies should focus on patient-important outcome measures, especially health-related quality of life, and compare minimally invasive procedures with surgery. RCTs with follow-up periods of several years and good-quality observational studies are needed to provide evidence on the development of thyroid cancer, all-cause mortality and long-term adverse events.

Managing terrorism or accidental nuclear errors, preparing for iodine-131 emergencies: a comprehensive review

Chernobyl demonstrated that iodine-131 (131I) released in a nuclear accident can cause malignant thyroid nodules to develop in children within a 300 mile radius of the incident. Timely potassium iodide (KI) administration can prevent the development of thyroid cancer and the American Thyroid Association (ATA) and a number of United States governmental agencies recommend KI prophylaxis. Current pre-distribution of KI by the United States government and other governments with nuclear reactors is probably ineffective. Thus we undertook a thorough scientific review, regarding emergency response to 131I exposures. We propose: (1) pre-distribution of KI to at risk populations; (2) prompt administration, within 2 hours of the incident; (3) utilization of a lowest effective KI dose; (4) distribution extension to at least 300 miles from the epicenter of a potential nuclear incident; (5) education of the public about dietary iodide sources; (6) continued post-hoc analysis of the long-term impact of nuclear accidents; and (7) support for global iodine sufficiency programs. Approximately two billion people are at risk for iodine deficiency disorder (IDD), the world's leading cause of preventable brain damage. Iodide deficient individuals are at greater risk of developing thyroid cancer after 131I exposure. There are virtually no studies of KI prophylaxis in infants, children and adolescents, our target population. Because of their sensitivity to these side effects, we have suggested that we should extrapolate from the lowest effective adult dose, 15-30 mg or 1-2 mg per 10 pounds for children. We encourage global health agencies (private and governmental) to consider these critical recommendations.

Role of cytological characteristics of benign thyroid nodules on effectiveness of their treatment with levothyroxine

INTRODUCTION

Levothyroxine (LT4) therapy has been used for the treatment of euthyroid nodular goiter, but there are controversial results about its usefulness. We aimed to evaluate the possible role of benign nodules' cytological characteristics in response to LT4 therapy.

MATERIAL AND METHODS

In total, 93 patients with 128 nodules were included in the study; 74 of the nodules were treated with LT4 (group 1), and 54 of them had no medication (group 2). The subgroups consisted of adenomatous nodules, colloid nodules and cystic nodules.

RESULTS

In group 1, mean thyroid volume and mean nodule volume were reduced significantly (p = 0.002 and p = 0.022, respectively) with low-normal level thyrotropin (TSH) suppression (between 0.3 mIU/ml and 1.0 mIU/ml), while there were no significant changes in group 2. When we evaluated changes of the initial and last nodule volumes in cytological subgroups, only colloid nodules in group 1 had significant reduction (p = 0.040) and the others had no significant changes. By omitting the colloid nodules, when the other nodules were revaluated, there were no significant changes in either group.

CONCLUSIONS

On the basis of these results, obtained from a large sample of Anatolian patients, it is possible that LT4 therapy leads to significant reductions of both thyroid volume and nodule size in colloid nodules, but not in other kinds of benign nodules.

Serum TSH and risk of papillary thyroid cancer in nodular thyroid disease

CONTEXT

TSH is the main factor involved in the control of proliferation of thyrocytes. Recently, a strong relationship between serum TSH and risk of thyroid malignancy has been reported.

OBJECTIVES

The aim was to review published papers about the relationship between serum TSH and frequency of differentiated thyroid cancer.

EVIDENCE ACQUISITION

PubMed was used to identify studies focused on the relationship between TSH and differentiated thyroid cancer.

EVIDENCE SYNTHESIS

In patients with nodular thyroid disease, the risk of thyroid malignancy increases with serum TSH, and even within normal ranges, higher TSH values are associated with a higher frequency and more advanced stage of thyroid cancer. The likelihood of papillary thyroid carcinoma is reduced when TSH is lower, as in thyroid autonomy, and increased when TSH is higher, as in thyroid autoimmunity. Treatment with l-thyroxine (LT4), which reduces serum TSH, is associated with significantly lower risk of developing clinically detectable thyroid cancer.

CONCLUSIONS

TSH plays a key role in the development of clinically detectable thyroid cancer, and LT4 treatment reduces the risk of thyroid malignancy in patients with nodular thyroid disease. According to the guidelines of the main scientific societies, LT4 therapy is not currently recommended for the treatment of patients with nodular goiter. Even if the available data are not sufficient to advise LT4 treatment in all patients with nodular goiter with the aim of reducing the risk of papillary thyroid carcinoma, we propose that this indication should be reconsidered, taking into account recent evidence reported in the literature.

Reduction of thyroid nodule volume by levothyroxine and iodine alone and in combination: a randomized, placebo-controlled trial

CONTEXT

Nodular goiter is common worldwide, but there is still debate over the medical treatment.

OBJECTIVE

The objective of the study was the measurement of the effect of a treatment with (nonsuppressive) T(4), iodine, or a combination of both compared with placebo on volume of thyroid nodules and thyroid.

DESIGN

This was a multicenter, randomized, double-blind trial in patients with nodular goiter in Germany [LISA (Levothyroxin und Iodid in der Strumatherapie Als Mono-oder Kombinationstherapie) trial].

SETTING

The study was conducted in outpatient clinics in university hospitals and regional hospitals and private practices.

PARTICIPANTS

One thousand twenty-four consecutively screened and centrally randomized euthyroid patients aged 18-65 yr with one or more thyroid nodules (minimal diameter 10 mm) participated in the study.

INTERVENTION

Intervention included placebo, iodine (I), T(4), or T(4)+I for 1 yr. T(4) doses were adapted for a TSH target range of 0.2-0.8 mU/liter.

OUTCOME MEASURES

The primary end point was percent volume reduction of all nodules measured by ultrasound, and the main secondary end point was a change in goiter volume.

RESULTS

Nodule volume reductions were -17.3% [95% confidence interval (CI) -24.8/-9.0%, P < 0.001] in the T(4)+I group, -7.3% (95% CI -15.0/+1.2%, P = 0.201) in the T(4) group, and -4.0% (95% CI -11.4/+4.2%, P = 0.328) in the I group as compared with placebo. In direct comparison, the T(4)+I therapy was significantly superior to T(4) (P = 0.018) or I (P = 0.003). Thyroid volume reductions were -7.9% (95% CI -11.8/-3.9%, P < 0.001), -5.2% (95% CI -8.7/-1.6%, P = 0.024) and -2.5% (95% CI -6.2/+1.4%, P = 0.207), respectively. The T(4)+I therapy was significantly superior to I (P = 0.034) but not to T(4) (P = 0.190).

CONCLUSION

In a region with a sufficient iodine supply, a 1-yr therapy with a combination of I and T(4) with incomplete suppression of thyrotropin reduced thyroid nodule volume further than either component alone or placebo.

High growth rate of benign thyroid nodules bearing RET/PTC rearrangements

CONTEXT

Benign thyroid nodules display a broad range of behaviors from a stationary size to a progressive growth. The RET/PTC oncogene has been documented in a fraction of benign thyroid nodules, besides papillary thyroid carcinomas, and it might therefore influence their growth.

OBJECTIVE

The aim of the present work was to evaluate whether RET/PTC in benign thyroid nodules associates with a different nodular growth rate.

STUDY DESIGN

In this prospective multicentric study, 125 subjects with benign nodules were included. RET rearrangements were analyzed in cytology samples; clinical and ultrasonographic nodule characteristics were assessed at the start and at the end of the study.

RESULTS

RET/PTC was present in 19 nodules. The difference between the mean baseline nodular volume of the RET/PTC- and RET/PTC+ nodules was not significant. After 36 months of follow-up, the RET/PTC+ group (n = 16) reached a volume higher than the RET/PTC- group (n = 90) (5.04 ± 2.67 vs. 3.04 ± 2.26 ml; P = 0.0028). We calculated the monthly change of nodule volumes as a percentage of baseline. After a mean follow-up of 36.6 months, the monthly volume increase of nodules bearing a RET rearrangement was 4.3-fold that of nodules with wild-type RET (1.83 ± 1.2 vs. 0.43 ± 1.0% of baseline volume; P < 0.0001).

CONCLUSIONS

Benign thyroid nodules bearing RET rearrangements grow more rapidly than those with wild-type RET. Searching for RET rearrangements in benign thyroid nodules might be useful to the clinician in choosing the more appropriate and timely therapeutic option.

A solid thyroid benign nodule that showed a significant decrease in size and ultrasonographic findings mimicking papillary carcinoma during 16-year follow-up

Recent advances in ultrasonography and fine needle aspiration biopsy (FNAB) have facilitated accurate diagnosis of thyroid carcinomas that require treatment. However, we often encounter nodules evaluated as malignant on ultrasonography but diagnosed as benign on cytology, for which the optimal treatment strategy remains uncertain. A 28-year-old female had solitary and solid thyroid nodule measuring 6 cm in maximal diameter in February 1994. The lesion was cytologically diagnosed as benign. From September 1998, the nodule spontaneously decreased in size but ultrasonographic findings suspicious of malignancy such as peripheral and intra-tumoral calcification, low internal echo and irregular border gradually appeared. In July 2010, the volume of her nodule showed 97% decrease but was evaluated as papillary carcinoma on ultrasonography. FNAB was performed again and the nodule was diagnosed as benign. When we encounter a nodule showing ultrasonographic findings suggestive of malignancy with negative cytology, we should consider the possibility of a benign nodule degenerating over time.

Thyroxine suppression therapy for benign, non-functioning solitary thyroid nodules: a quality-effects meta-analysis

Levothyroxine (LT4) suppressive therapy for solitary thyroid nodules is not popularly advocated presently because its clinical efficacy and safety are currently considered controversial. This meta-analysis aims to address efficacy issues by using rigorous methods to arrive at a pooled estimate. On the basis of the analysis, it is estimated that LT4 therapy is clearly associated with up to a two-fold increase in the chance of nodule reduction. This translates to a number needed to treat (NNT) of 6 or a 50% decrease in the risk of cancer given nodule reduction. Keeping this definition of efficacy in mind and a low incidence of adverse events with low level LT4 suppression, such an intervention might be appropriate in patients selected on the basis of a low risk for adverse effects.

Ultrasonographic characteristics as a criterion for repeat cytology in benign thyroid nodules

OBJECTIVE: To report the results of repeat fine-needle aspiration cytology (FNAC) in thyroid nodules with an initial benign cytological diagnosis that grow during follow-up and/or present suspicious ultrasonographic characteristics. SUBJECTS AND METHODS: The sample consisted of 456 patients with 895 nodules. FNAC was repeated after 12 to 18 months in the case of nodules with suspicious ultrasonographic characteristics, irrespective of growth, and when the nodules showed significant growth. RESULTS: Among the 895 nodules examined, 102 (11.4%) presented suspicious ultrasonographic characteristics. The second FNAC revealed malignancy in 18 (17.6%) nodules, including 20% (2/10) of those showing growth and 17.4% (16/92) that did not. Seventy-six (9.6%) of 793 nodules without suspicious characteristics presented growth. Only one case (1.3%) of malignancy was diagnosed by repeat FNAC. CONCLUSIONS: The study suggests ultrasonographic characteristics rather than growth as a criterion for repeat FNAC in the case of nodules with an initial benign cytological diagnosis.

Short term effects of levothyroxine treatment in thyroid multinodular disease

The levothyroxine suppressive efficacy in benign thyroid nodules treatment is well described in uninodular non-toxic goiter, whereas only few controlled trials enrolled patients with multinodular disease. The aim of the present study is to evaluate the short term effects of levothyroxine treatment in never treated, pre-menopausal women affected by thyroid multinodular disease. Seventy-one pre-menopausal women with thyroid multinodular disease, still presenting normal TSH levels, from Latina area were randomly assigned to a levothyroxine treated or control group. Biochemical and ultrasonography evaluations of thyroid were monitored at the enrollment and after 6, 12 and 24 months of treatment. In the levothyroxine treated group, after 1 year of treatment, thyroid and dominant nodule volume and number of nodules >0.5 mL significantly decreased from a median of 12.0 to 9.8 mL (p <0.001), from 1.0 to 0.5 mL (p <0.001) and from 0.5 to 0, respectively. Conversely, in the control group significant augmented values of these parameters were observed (p =0.007, p <0.001 and p <0.001, respectively). Furthermore, these observations were also confirmed by results obtained after a 24 months follow-up period. Our data support previous observations on the clinical usefulness of L-T(4) treatment in preventing thyroid and nodule volume and nodule numbers growth. These findings confirm the tendency of benign nodular disease toward progression and the efficacy of TSH suppression in preventing its evolution by means of removing the major growth factor for thyroid nodules still responsive to physiological stimuli.

Value of US correlation of a thyroid nodule with initially benign cytologic results

PURPOSE

To investigate the value of ultrasonographic (US) features in thyroid nodules with initially benign cytologic results.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and required neither patient approval nor informed consent for the review of images and records. From October 2003 to February 2006, 6118 focal thyroid nodules in 6025 consecutive patients underwent US-guided fine-needle aspiration biopsy (FNAB). This study included 1343 nodules 1 cm or larger in 1302 patients that were diagnosed as benign at initial cytologic evaluation and underwent pathologic or follow-up study. We compared the risk of malignancy according to US findings and calculated the likelihoods of different subgroups having benign nodules.

RESULTS

In total, 26 (1.9%) malignant and 1317 (98.1%) benign nodules were found according to reference standards. If initial cytologic results showed benign thyroid nodules, the likelihood of the nodule actually being benign was 98.1%. When a thyroid nodule had benign results at both initial and repeat FNAB, the likelihood increased to 100%. The likelihood of having a benign thyroid nodule with suspicious US features was lower (79.6%) than having a benign thyroid nodule with negative US features (99.4%, P<.001). In the nodule with benign features at initial US, the risk of malignancy for a thyroid nodule with an increase in size at follow-up US was slightly higher (1.4%) than that of a thyroid nodule with no interval change or decrease in size, but it was not significantly different (0.5%, P = .354).

CONCLUSION

Repeat FNAB should be performed for thyroid nodules that have suspicious US features, even if the initial cytologic results indicate that it is a benign lesion.

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.

Clinical evolution of autoimmune thyroiditis in children and adolescents

BACKGROUND

Few studies have addressed the clinical evolution of autoimmune thyroiditis (AIT) occurring in childhood and scant data are available on the role of thyroid ultrasonography. We aimed to evaluate the natural history of AIT diagnosed in children and adolescents and to assess the possible prognostic role of ultrasonography.

METHODS

Retrospective case series prospectively followed up for a further 3-year period.

RESULTS

A series of 23 patients with AIT, diagnosed before 18 years of age from 1994 to 2004, was further followed up from 2005 to 2007 with clinical, laboratory, and ultrasound evaluation. Hypothyroid patients were treated with levothyroxine (LT(4)), while euthyroid patients were left untreated. Patients with subclinical hypothyroidism were also evaluated 40 days after LT(4) withdrawal. At diagnosis seven patients were euthyroid, 14 with subclinical hypothyroidism, and two with overt hypothyroidism. Median follow-up was 4.7 years. At last follow-up visit, none of the seven euthyroid patients had developed hypothyroidism. Three of the 14 patients with subclinical hypothyroidism recovered a normal thyroid function while only one patient showed an increase in TSH level. By serological screening we identified three patients with other autoimmune disorders.

CONCLUSIONS

In young patients with normal or mildly increased TSH levels and minimal echographic changes, AIT may remain stationary for years. In fact, patients with subclinical hypothyroidism recover a normal thyroid function in approximately 20% of cases. In patients with subclinical hypothyroidism and goiter, LT(4) therapy may induce thyroid size reduction. Screening for other autoimmune disorders is useful to identify patients that need further diagnostic assessment.

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.

Thyroxine therapy in euthyroid patients does not affect body composition or muscular function

OBJECTIVE

The main objective of the study was to evaluate the effects of small increments in thyroxine (T4) levels following levothyroxine (L-T4) administration on the body composition of women patients. The secondary objective was to assess the effect of the therapy on energy expenditure and muscular function.

METHODS

The prospective, randomized study consisted of a 12-month follow-up of 37 women with thyroid nodules. The patients were divided into two groups for comparison, one treated with L-T4 (20 women) and the other untreated (17 women). L-T4 dose was individually adjusted to obtain a serum thyroid-stimulating hormone in the lower portion of the normal range. Multiple tests, including bioelectrical impedance analysis, dual-energy X-ray absorptiometry, air displacement plethysmography, measurement of waist circumference, and skinfold anthropometry, were used to investigate the muscular, fat, and water compartments; energy expenditure and muscular function were assessed by cycle ergometry.

RESULTS

There were no significant differences in body composition, heart rate, energy metabolism, or muscular function between the group of women treated with L-T4 and the untreated group.

CONCLUSION

The controlled increase of circulating T4 does not appear to modify the body composition or muscular function in women patients.

Nonsurgical approaches to the management of thyroid nodules

Epidemiologic studies have documented substantial increases in the frequency of nodular thyroid disease. This trend is largely due to the increasing detection of nodules by the routine use of sonography in clinical practice. Only a small percentage of the nodules currently being detected will prove to be malignant. The probability of malignancy is similar in nonpalpable and palpable nodules. Fine-needle aspiration cytology has a central role in identifying malignant nodules, which are generally treated with surgery. Most thyroid nodules are cytologically benign and can be managed nonsurgically. Nodules that are completely asymptomatic require follow-up without treatment. Cosmetic problems and/or compression-related symptoms may be indications for surgery. When surgery is contraindicated or refused, several nonsurgical approaches are available. These include levothyroxine therapy, radioiodine treatment, percutaneous ethanol injections, and the new technique of laser photocoagulation. Levothyroxine therapy is the most widely used approach, but its clinical efficacy and safety are controversial. Levothyroxine might, nonetheless, be appropriate in selected cases characterized by low risk for adverse effects and nodule characteristics associated with response to this type of therapy. Radioiodine is the therapy of choice for toxic nodules or for symptomatic nodular goiters when surgery is not possible. Percutaneous ethanol injection should be used, in our opinion, as the first-line therapy only for recurrent symptomatic cystic nodules. Laser therapy should be reserved for selected patients treated in experienced centers only. With these options, clinicians can personalize the management of nodular thyroid disease according to a careful cost-benefit analysis.

The effect of thyroxine-suppressive therapy in patients with solitary non-toxic thyroid nodules -- a randomised, double-blind, placebo-controlled study

The efficacy of thyroxine (T(4)) for solitary non-toxic thyroid nodule remains uncertain. In this study, 60 patients with solitary non-toxic thyroid nodule were divided randomly into two groups. Group I (n = 30) received thyroxine 100 microg/day for 6 months and group II (n = 30) received placebo. The volume of the thyroid nodules in 11 patients decreased more than 50% after thyroxine therapy (36.7%, responders). In these 11 patients, the mean serum thyroglobulin level decreased significantly (340 +/- 115 to 162 +/- 86 microg/l, p < 0.01). Compared with the non-responders (n = 19, 63.3%), the serum thyroglobulin level before treatment was significantly higher (340 +/- 115 vs. 220 +/- 102 microg/l, p < 0.05). Thyroxine-suppressive therapy is proved as a useful tool in reducing nodule size in some patients with solitary thyroid nodules. The patients with a higher serum thyroglobulin level generally respond better to thyroxine-suppressive therapy.

Interobserver variation for ultrasound determination of thyroid nodule volumes

Thyroid ultrasound is used in the routine clinical assessment and the follow-up of thyroid disorders. The follow- up of patients with thyroid nodules is mostly based on thyroid nodule volume determinations performed by different observers. However, for the judgment of treatment effects there is uncertainty about the interobserver variation of thyroid nodule volume measurements by ultrasound because there are no prospective blinded studies available comparing the interobserver variation in thyroid nodule volume measurement. The aim of our study was therefore to determine the variation of thyroid nodule volume determinations for different observers. We conducted a prospective blinded trial. Our study population consisted of 42 probands (8 men, 34 women) with an uniform distribution of thyroid nodule sizes (25 uninodular and 17 multinodular thyroid glands). We compared the results of 3 ultrasonographers with certified experience in thyroid ultrasound. The interobserver variation for the determination of thyroid nodule volume (n = 38) was 48.96% for the ellipsoid method and 48.64% for the planimetric method. The interobserver variation for determining thyroid volume (n = 40) was 23.69% for the ellipsoid method and 17.82% for the planimetric method. A regression analysis revealed that the probability for the identification of the same nodule in nodular thyroids by all sonographers is 90%, if the nodule is at least 15mm in greatest diameter. Future investigations should not describe changes in nodule volume less than 50% as therapy effects because only volume changes of at least 49% or more can be interpreted as nodule shrinkage or growth. Reporting of nodule volume modification 50% or more and lack of information for ultrasound procedures introduce a bias in studies evaluating the effects of nodule treatments. The clinical interpretation of a shrinking/growing thyroid nodule based on volume determinations by ultrasound is not well established because it is difficult to reproduce a two-dimensional image plane for follow-up studies.

Molecular pathogenesis of euthyroid and toxic multinodular goiter

The purpose of this review is to summarize current knowledge of the etiology of euthyroid and toxic multinodular goiter (MNG) with respect to the epidemiology, clinical characteristics, and molecular pathology. In reconstructing the line of events from early thyroid hyperplasia to MNG we will argue the predominant neoplastic character of nodular structures, the nature of known somatic mutations, and the importance of mutagenesis. Furthermore, we outline direct and indirect consequences of these somatic mutations for thyroid pathophysiology and summarize information concerning a possible genetic background of euthyroid goiter. Finally, we discuss uncertainties and open questions in differential diagnosis and therapy of euthyroid and toxic MNG.

Ultrasound-detected thyroid nodules in radiation-exposed patients: changes over time

The relationship between radiation exposure and thyroid cancer is well known, but whether all irradiated patients should have thyroid ultrasounds is unresolved. We have performed follow-up ultrasound examinations of patients in a cohort who were exposed to conventional external radiation during 1939-63 for benign conditions of the head and neck area prior to their 16th birthday. Of 54 subjects who had normal radionuclide scans in 1974-76 and were reexamined in 1996-97 by thyroid ultrasonography, 42 remained eligible and 34 agreed to participate in the present ultrasound study. After an additional 4-8 years of follow-up and using an ultrasound machine with increased resolution, we found 160 nodules (in 33 of these 34 subjects), compared with 96 nodules (in 29 of the 34 subjects) detected in the previous examination. Only four of the new nodules were > or =10 mm. Of the previously diagnosed large (> or =10 mm) nodules, four nodules in four subjects resolved; nine nodules in six subjects regressed to <10 mm; 14 nodules in 13 subjects remained at > or =10 mm. The four new large nodules appeared in four subjects, and six small nodules increased to > or =10 mm in six other subjects. The total volume of the thyroid nodules decreased in the 13 subjects on thyroid hormone (by 0.20 cm(3)) and increased in the 21 subjects who were not (by 0.34 cm(3), p < 0.05 by unpaired t-test). In summary, thyroid nodules are extremely common in irradiated subjects. Many new ones may be observed over time, but most are small and seen because of the increased resolution of ultrasound machines. Compared to patients on no medication, nodules in patients on thyroid hormone tended to regress. Since FNA of all thyroid nodules in irradiated patients is not feasible, ultrasound is useful in identifying those lesions that are growing.

Neural network analysis for evaluating cancer risk in thyroid nodules with an indeterminate diagnosis at aspiration cytology: identification of a low-risk subgroup

Thyroid nodules with a predominant follicular structure are often diagnosed as indeterminate at fine-needle aspiration biopsy (FNAB). We studied 453 patients with a thyroid nodule diagnosed as indeterminate at FNAB by using a feed-forward artificial neural network (ANN) analysis to integrate cytologic and clinical data, with the goal of subgrouping patients into a high-risk and in a low-risk category. Three hundred seventy-one patients were used to train the network and 82 patients were used to validate the model. The cytologic smears were blindly reviewed and classified in a high-risk and a low-risk subgroup on the basis of standard criteria. Neural network analysis subdivided the 371 lesions of the first series into a high-risk group (cancer rate of approximately 33% at histology) and a low-risk group (cancer rate of 3%). Only cytologic parameters contributed to this classification. Analysis of the receiver operating characteristic (ROC) curves demonstrated that the ANN model discriminated with higher sensitivity and specificity between benign and malignant nodules compared to standard cytologic criteria (p < 0.001). This value did not show degradation when ANN predictions were applied to the validation series of 82 nodules. In conclusion, neural network analysis of cytologic data may be a useful tool to refine the risk of cancer in patients with lesions diagnosed as indeterminate by FNAB.

Slow growth of benign thyroid nodules after menopause: no need for long-term thyroxine suppressive therapy in post-menopausal women

Benign thyroid nodules represent a very common disorder, the management of which is still controversial. The aim of the present work was to evaluate by ultrasound examination the volume changes of thyroid nodules in post-menopausal women presenting single palpable nodular goiter of recent onset (less than 6 months from diagnosis). Forty-three patients received L-T4-treatment, 38 represented the no-treatment group. Long-term follow up (3 and 5 yr) did not show any significant change in the mean volume nodule in these patients. In the no-treatment group, the mean nodule volumes were stable over time from baseline to 5 yr. No significant difference was observed at any follow-up evaluation between thyroid hormone treated and untreated patients. After 1 yr of treatment, a significant decrease (p = 0.0275) in mean nodule volume occurred only for nodules with a baseline volume lower than 1.5 ml. The frequency of clinically relevant nodule size variation showed a more frequent decrease (13.9%) at 1 yr in the L-T4 group, as compared to the no-treatment group (2.6%), while the proportion of increased volume at 1 yr was higher in the untreated than in the L-T4 group (5.3% vs 2.3%). This inverse relationship between the 2 groups was not statistically significant (p = 0.076). In conclusion, an arrest in the growth of benign thyroid nodules occurs in the majority of women after menopause. Only a very limited number of these patients may benefit from thyroid hormone suppressive treatment.

Changing Trends in Thyroid Practice: Understanding Nodular Thyroid Disease

OBJECTIVE

To describe changes that have occurred between 1952 and 2002 in the evaluation and management of nodular thyroid disease.

METHODS

A 30-year personal experience, institutional contributions, and the related published literature on evaluation of thyroid function and evolving strategies for management of thyroid nodules are reviewed.

RESULTS

Triiodothyronine (T(3)) was discovered in 1952, and measurement of plasma thyroxine by a competitive protein-binding technique became available in the 1960s. Late during that decade, the first radioimmunoassay for thyroid-stimulating hormone (TSH) was described, modified, and then used in clinical practice until the mid-1980s, when the more sensitive TSH assays became widely available. T(3) determination by radioimmunoassay was introduced early in the 1970s. Currently, sensitive thyroid function tests can detect early disease. In the general population, thyroid nodules have a prevalence higher than 50% after age 65 years, affecting more than 100 million people in the United States. Two important developments influenced thyroid nodule evaluation and management-- fine-needle aspiration (FNA) biopsy and ultrasonography. Because FNA biopsy has emerged as the most accurate test for nodule diagnosis, it has decreased the need for scanning and for thyroidectomy and thereby is likely to reduce health-care costs by more than $500 million annually in the United States. Thyroid ultrasonography is the imaging method of choice for evaluation of thyroid gland structure. Management of cytologically benign thyroid nodules remains controversial.

CONCLUSION

TSH seems to be only one of many factors in pathologic thyroid growth. FNA, because of its diagnostic accuracy, should be the initial procedure used in nodule evaluation.

Changes in both size and cytological features of thyroid nodule after levothyroxine treatment

OBJECTIVE

We prospectively evaluated the effects of 12 months thyrotropin suppressive levo-thyroxine (L-T4) therapy in terms of changes in both thyroid nodule size and cytological features and considered whether thyroid nodule size changes actually resulted in (or were the result of) cytological changes.

DESIGN AND PATIENTS

We studied 142 consecutive patients with benign 'cold' solitary thyroid nodules. For the purposes of the study, we divided our patients into three groups according to their initial cytological nodule classification as follows: group 1, including 88 colloid nodules (CN); group 2, including 30 hyperplastic nodules (HN); and group 3, including 24 adenomatous nodules (AN).

MEASUREMENTS

The effects of TSH suppressive L-T4 treatment on both nodule volume and cytological characteristics were evaluated by ultrasonography and fine-needle aspiration (FNA) before and 12 months after the onset of therapy.

RESULTS

Twelve months of TSH suppressive L-T4 treatment were effective in shrinking about one-third to one-quarter (31.8% CN, 26.7% HN and 25% AN) of thyroid nodules, irrespective of their initial cytological characteristics. Similarly, there was no difference in the prevalence of 'non-responders' (increasing nodules) to L-T4, which accounted for about one-fifth or less (20.5% CN, 13.3% HN and 20.8% AN) of all nodules. We found also that cytological features changed in 33.8% nodules after 12 months of L-T4 treatment. These changes were most commonly observed in HN and AN and consisted largely ( approximately 80%) of cytological characteristics resembling colloid features, not only in shrinking but also in stable nodules, thus indicating that cytology changes might be the very first indicator of nodule sensitivity to L-T4 therapy even in the continued absence of nodule shrinkage. When nodules were divided into three subgroups according to variations in size (shrinking, stable and increasing nodules), we observed that the distribution of the three cytological types showed a trend towards colloid lesions in shrinking nodules (chi2 3.8, P < 0.005) and towards an augmentation of hypercellular, adenomatous and suspicious characteristics in increasing nodules (chi2 3.6, P < 0.005).

CONCLUSION

The frequency of shrinking nodules was not different between colloid, hyperplastic and adenomatous nodules. Repeat FNA should be advisable for thyroid nodules which increase in volume despite L-T4 therapy and might also provide useful information about nodule sensitivity to L-T4 treatment for both HN and AN, even where nodule size remains stable.

Ultrasound thyroid nodule measurements: the "gold standard" and its limitations in clinical decision making

OBJECTIVE

To highlight the limitations associated with use of ultrasonography for the evaluation of thyroid nodule or gland volume for clinical decision making.

METHODS

We review the equipment (scanners and probes) used for ultrasonography and the appropriate measurements for assessment of thyroid nodules. The limitations of ultrasound thyroid measurements are summarized, particularly in reference to repeated measurements over time.

RESULTS

Thyroid ultrasonography is the recognized "gold standard" for an accurate and reliable assessment of gland volume and thyroid nodules. Many endocrinologists refer patients for surgical treatment because of detection of growth of thyroid nodules. In daily practice, they often make this decision by comparing ultrasound thyroid measurements determined over time. Although reliable, evaluation of thyroid nodule volume by ultrasonography has technologic, biologic, and examination technique limitations. These are particularly important in routine clinical practice, where ultrasound measurements are performed in less standardized settings than in experimental trials.

CONCLUSION

In daily medical office applications, ultrasound measurements of thyroid nodules should be used with caution in decision making.

Effect of low- and high-dose levothyroxine on thyroid nodule volume: a crossover placebo-controlled trial

OBJECTIVE

The efficacy and the effective dose of levothyroxine suppressive therapy in the treatment of benign thyroid nodules are controversial. In this study, we aimed to determine the response of solitary thyroid nodules to low- or high-level TSH suppression in a placebo-controlled, randomized crossover trial.

DESIGN

Forty-nine patients with solitary thyroid nodules on palpation were randomized to high-level and low-level TSH suppression groups. In each group, patients were further randomized to placebo and active levothyroxine subgroups. Patients in each subgroup were crossed over to placebo or active levothyroxine at the end of the first year and were then followed up for an additional year.

METHODS

TSH levels were suppressed to 0.4-0.6 mIU/ml and < or = 0.01 mIU/ml in the low-level and high-level TSH suppression groups, respectively. Nodule volumes were measured at baseline and every 6 months after the desired level of TSH was reached if the patients were in the active levothyroxine treatment group or every 6 months if they were in the placebo group.

RESULTS

In high-level TSH suppression groups, nodule volume decreased significantly at the end of the active treatment periods (4.99 +/- 2.02 ml vs. 3.20 +/- 1.50 ml, P < 0.01, in Group 1; and 3.72 +/- 1.79 ml to 2.05 +/- 0.64 ml, P < 0.001, in Group 2). In the low-level TSH suppression groups, nodule volume also decreased significantly at the end of the active treatment periods (4.43 +/- 1.76 ml vs. 3.04 +/- 1.32, P < 0.05, in Group 3; and 3.59 +/- 0.89 ml to 2.22 +/- 0.59 ml, P < 0.01, in Group 4). Nodule volumes regained their original volumes during the placebo treatment periods. The percentage decline in clinically relevant nodule volume reduction (> or = 50%) was similar in the low-level and high-level TSH suppression groups.

CONCLUSION

Low- and high-level TSH suppression were equally effective in reducing nodule volume and thus, considering the complications of high-level TSH suppression, low-level TSH suppression should be used if one considers levothyroxine suppressive therapy to reduce thyroid nodule size.

Iodized salt improves the effectiveness of L-thyroxine therapy after surgery for nontoxic goitre: a prospective and randomized study

OBJECTIVE

To investigate whether the addition of iodized salt to daily diet in thyroidectomized patients for nontoxic goitre could influence the effectiveness of nonsuppressive L-thyroxine (L-T4) therapy on thyroid remnant size, during 12 months' follow-up after thyroid surgery.

DESIGN AND PATIENTS

A consecutive series of selected 139 patients (26 males, 113 females; median age 45 years, range 30-69 years) living in a moderate iodine-deficient area, and undergoing thyroid surgery for nontoxic multinodular goitre, was enrolled. Patients were assigned randomly to two different therapeutic regimens: 70 patients received L-T4 therapy alone (Gr. L-T4), while the remaining 69 patients took iodized salt on a daily basis in addition to L-T4 treatment (Gr. L-T4 + I). In both groups, the initial L-T4 dose was 1.5 microg/kg/day, which, in our experience, has been shown to be intermediate between suppressive and replacement doses. To avoid the risks of mild thyrotoxicosis and to limit the excessive TSH stimulation of the thyroid remnant, the L-T4 dose was adjusted in those patients with serum TSH levels outside the lowest two-thirds of the normal range (0.3-2.5 mU/l). An ultrasound evaluation of thyroid remnant size was performed after thyroid surgery and 12 months later.

RESULTS

After surgery, the median thyroid remnant volume was 3.5 ml (range 0.4-13.9 ml) in Gr. L-T4 and 4.6 ml (range 0.5-12.7 ml) in Gr. L-T4 + I (P = 0.06). After 1 year of follow-up, the patients treated with L-T4 + I obtained a remnant volume reduction (-39.7%, range -87.0% to +91.2%) significantly (P = 0.006) greater than that observed in patients assuming L-T4 alone (-10.2%, range -89.4% to +85.0%). However, the percentage of patients showing an increase in remnant size in the months following surgery was higher in Gr. L-T4 than in Gr. L-T4 + I (22/60 vs. 9/66; P = 0.01). In Gr. L-T4 patients the thyroid remnant volume variation throughout 12 months of treatment was correlated significantly with the size of the thyroid remnant found at the first ultrasound evaluation (R(2) = 0.3; P < 0.001). No such correlation was found in Gr. L-T4 + I patients, for whom the therapy maintains a similar effectiveness in patients with either a large or a small postsurgery thyroid remnant. In patients treated with L-T4 alone, the remnant volume variation was correlated significantly with the median serum TSH values attained in the course of treatment (R2 = 0.4; P < 0.001). The highest reduction in remnant volume was observed only by lowering the serum TSH concentrations. In patients treated with L-T4 plus iodine, instead, the thyroid remnant volume reduction occurred independently of the plasma TSH levels attained in the course of treatment.

CONCLUSIONS

Our short-term prospective and randomized study leads us to conclude that, in patients living in a moderate iodine-deficient area and undergoing thyroid surgery for nontoxic goitre: (1) the iodine prophylaxis improves the effects of postsurgery nonsuppressive L-T4 therapy on thyroid remnant size. (2) In patients treated with L-T4 alone the therapeutic effectiveness decreases in the presence of a large postsurgery thyroid remnant. With the addition of iodine, the L-T4 maintains a similar efficacy in patients with either a large or a small remnant. (3) During treatment with L-T4 alone the highest therapeutic effectiveness is attained by lowering the plasma TSH concentration. With the addition of iodized salt to the daily diet the effects of L-T4 on remnant size are relevant independently of the TSH levels.

Pharmacotherapy for thyroid nodules. A systematic review and meta-analysis

The review highlights the uncertainty in the management of nodular thyroid disease. Thyroxine suppressive treatment is given in the hope that nodules might decrease in size, sometimes assuming that dependency on TSH is different in benign and malignant nodular disease. Follow-up of benign nodules over 10 years suggested that most remain the same, shrink, or disappear [14]. TSH suppression may lead to hyperthyroidism, reduced bone density [37.39], and atrial fibrilation; however, apart from reduction of nodule size or arrest in nodule growth, thyroxine therapy may benefit patients by reducing perinodular volume. Consequently, both pressure symptoms and cosmetic complaints could improve. Unfortunately, no information concerning symptoms or well-being is available from published randomized trials. In conclusion, more high quality studies of sufficient duration with adequate power estimation are needed. Uncertainty about predictors of response or the impact on outcomes that are important to patients leaves considerable doubt about the wisdom of applying suppressive therapy. Future studies shoudl include patient-important outcomes including thyroid cancer incidence, health-related quality of life and costs.

Effectiveness of thyroid hormone suppressive therapy in benign solitary thyroid nodules: a meta-analysis

The effectiveness of thyroid hormone suppressive therapy in reducing the volume of benign thyroid nodules is controversial. It is important to clarify this therapeutic effect of thyroid hormone, because its prolonged use needs to be carefully weighed against its potential deleterious effects in the skeletal and cardiovascular systems. To evaluate the best available evidence, we conducted a systematic review and meta-analysis of the randomized controlled trials that fulfill the following inclusion criteria: single thyroid nodules proven benign by fine needle aspiration, treatment, and follow-up of at least 6 months; documented suppression of TSH; measurement of thyroid nodule volume by ultrasound; and response to therapy defined as more than 50% volume reduction from baseline. Six randomized clinical trials published between 1987 and 1999, with 346 patients, were included in the meta-analysis. Ninety percent of the participants were female. Using a random effects model, the overall effect size showed a relative risk of 1.9 (95% confidence interval, 0.95-3.81) favoring a treatment effect. A sensitivity analysis showed significant changes in the results. Suppressive thyroid hormone therapy for longer than 6 months is associated with a trend toward a reduction of more than 50% in volume of benign thyroid nodules, without achieving statistical significance. The results are highly sensitive to changes in the statistical analysis, especially if the method used ignores heterogeneity among the effect sizes. More studies are needed before this therapy can be widely recommended.

Fine-needle aspiration biopsy of the thyroid

The routine use of thyroid FNAB caused profound changes in the management of thyroid nodules. FNAB allows a prompt identification and treatment of thyroid malignancies and avoids unnecessary surgery in patients with benign lesions, improving quality of life in patients with thyroid nodules. Furthermore, FNAB provides guidance for the type of surgery and reduces costs of care. On average, standard FNAB is nondiagnostic in 25% to 40% of cases, which include inadequate specimens and indeterminate (suspicious) diagnoses. In addition, a small percentage of false-negative diagnoses occur, which are unavoidable and raise concern of a late diagnosis of cancer. To minimize the limitations of FNAB, every center should reach and maintain a high standard of expertise in all of the steps of smear preparation and interpretation. Alternative modes of sampling or sample preparation may result in a reduction of nondiagnostic samples and better accuracy. Every center should set up clinical guidelines tailored to their own FNAB results and including the evaluation of clinical data. More work is needed to increase the accuracy of FNAB in suspicious cases. Toward this goal a variety of molecular markers have been evaluated; although none of them are ideal, some are promising. More studies need to be carried out in larger series to further evaluate the accuracy of these markers in identifying specific cancer histotypes within the group of suspicious lesions. It is hoped that, in the near future, the routine use of a combination of these markers will cost-effectively improve the diagnosis of malignant nodules classified as suspicious on traditional cytology. Statistical methods such as bayesian analysis or neural networks can be advantageously used to integrate different relevant information derived from family and personal history, clinical data, cytologic results, and evaluation of molecular markers.

Serum thyroglobulin measurement. Utility in clinical practice

Serum thyroglobulin measurement has greatly facilitated the clinical management of patients with differentiated thyroid cancer and a variety of other thyroid disorders. Thyroglobulin autoantibodies remain a significant obstacle to the clinical use of thyroglobulin measurement. The interpretation of any given thyroglobulin value requires the careful synthesis of all pertinent clinical and laboratory data available to the clinician. The diagnostic use of rhTSH-stimulated thyroglobulin levels has greatly facilitated the follow-up of low-risk patients with thyroid cancer. Although the measurement of thyroglobulin mRNA from peripheral blood is likely to affect the future management of these patients, it is expected that serum thyroglobulin measurement will continue to have a principal role in the care of patients with differentiated thyroid cancer.

Thyroid nodules: pathogenesis, diagnosis and treatment

Thyroid nodules are very frequently found and their prevalence steadily increases with age. The discovery of such lesions by high-resolution radiological imaging procedures that have been performed for other indications raises the problem of how incidentally discovered thyroid nodules should be investigated in a cost-effective manner to identify the rare patient with a clinically significant malignancy. In this review the clinical criteria that prompt the evaluation of thyroid nodules are discussed, as is the currently recommended diagnostic approach, which principally relies on fine needle aspiration biopsy. The clinical implications of the different cytological diagnoses are discussed, with a special emphasis on the management of indeterminate, microfollicular lesions. Finally, the evidence for and against suppressive thyroid hormone therapy for benign thyroid nodules and multinodular goitres is discussed, with particular consideration of high-risk patients with prior external radiation therapy to the neck region.

Assessing the effects of thyroid suppression on benign solitary thyroid nodules. A model for using quantitative research synthesis

Systematic review of the available information with a modified, largely quantitative method of research synthesis disclosed that an initial trial of thyroid hormone suppression therapy leads to clinically significant (> or = 50%) reduction of nodule size or arrest of nodule growth in a subset of patients with benign solitary thyroid nodules. In fact, in addition to objective improvements due to decreasing nodule size, L-T4 suppression therapy may benefit patients by reducing perinodular thyroid volume. Consequently, both pressure symptoms and cosmetic complaints may improve (9, 68). Additional studies for the assessment of the risks versus benefits of supraphysiologic doses of L-T4, the optimal level of thyroid suppression and the dose needed to achieve this magnitude of reduction, the optimal length of the initial trial, and the conditions for the continuation of L-T4 thyroid suppression therapy, as well as the identification of markers for patients most likely to respond to this therapy, are warranted. Finally, quantitative assessment of available evidence as described here may be applicable to the review of other controversial issues as well.

Solitary nodular disease and multinodular goiter: a retrospective study on suppressive versus replacement levothyroxine therapy

The aim of the present study was to ascertain whether patients affected by solitary nodular disease of the thyroid or multinodular goiter had a different clinical outcome when treated with suppressive levo-thyroxine (L-T4) therapy rather than replacement L-T4 therapy. We evaluated, by a retrospective analysis, 36 patients who had received TSH-suppressive L-T4 therapy according to TSH value and 55 who had received replacement L-T4 therapy. Fine needle aspiration cytology and thyroid scan after 131I were evaluated before L-T4 administration, while echographic monitoring of number and dimensions of nodules was recorded prior to and during L-T4 treatment. No difference in duration of L-T4 treatment (about 3 years) was registered between the TSH-suppressive therapy group and replacement therapy group. L-T4 administration in a TSH-suppressive or replacement manner did not induce a numerical or volumetric significant decrease of the main nodule or of the total nodule volume. Our data show that chronic TSH-suppressive therapy does not seem to be better than replacement therapy. Moreover, TSH-suppressive therapy presented a higher risk of adverse events than replacement therapy, thus requiring a more careful check with a higher cost of care.

Percutaneous ethanol injection therapy in benign solitary solid cold thyroid nodules: a randomized trial comparing one injection with three injections

The aim of the present study was to evaluate the efficacy of percutaneous ethanol injection therapy (PEIT) with special reference to dose response and symptom score and to describe side effects in a parallel-group randomized clinical trial with 6 months of follow-up, comparing 2 different treatment strategies. Sixty euthyroid outpatients with a benign solid and scintigraphically solitary cold thyroid nodule causing local discomfort were assigned to 1 session with a single intranodular injection of sterile 98% ethanol (PEIT-1, n = 30) or 3 weekly sessions with 1 injection of sterile 98% ethanol (PEIT-3, n = 30). In the PEIT-1 group, the pretreatment nodule volume was 9.9+/-5.7 mL (mean +/- SD). It decreased to 7.0+/-4.7 mL after 1 month, and 5.6+/-5.9 mL after 6 months (p = 3.2x10(-6)), and the ethanol dose given was 24.7%+/-7.5% of the pretreatment nodule volume. The overall reduction in nodule volume was 46%. In the PEIT-3 group the pretreatment nodule volume was 9.4+/-4.2 mL. It decreased to 5.9+/-3.5 mL 1 month after the last session, and 4.6+/-2.6 mL after 6 months (p = 4.0x10(-10)), and the cumulative ethanol dose given was 47.9%+/-21.3% of the pretreatment nodule volume. The overall reduction in nodule volume was 51%, and the difference between the 2 treatment regimens was 5.3%+/-5.5% (mean +/- SE of difference, p = 0.3). A satisfactory treatment dose, defined as a total intranodular spread of ethanol visualized on the monitor screen, was achieved in only 50%-60% of the sessions. This was due to pain that necessitated premature discontinuation of the injection and was apparently severe enough in 3 patients in the PEIT-3 group that they refused additional treatment. Twenty-two of 30 (73%) patients in the PEIT-1 group and 19 of 30 (63%) in the PEIT-3 group had a marked effect on symptoms at 6-month follow-up (p = 0.6). Side effects comprised transient thyrotoxicosis in 2 patients, permanent ipsilateral facial dysesthesia and increased flow of tears in 1 patient, paranodular fibrosis impeding subsequent surgery in 1 case and various degrees of pain and tenderness related to PEIT in nearly all. Major side effects were dose dependent. We conclude that PEIT is effective in inducing necrosis and reducing the volume of benign solid cold thyroid nodules. The additive effect of 2 additional doses compared with 1 dose is insignificant. The optimum management strategy has yet to be clarified. Limitations relate to the procedure being quite painful despite local anesthesia and the fact that side effects are in no way negligible, and therefore, a word of caution in routine use is advisable.

Treatment of large cold benign thyroid nodules not eligible for surgery with percutaneous ethanol injection

We studied the effect of percutaneous ethanol injection (PEI) in the treatment of cold, cytologically benign, large (>10 mL) thyroid nodules (CBNs) in 41 patients. The end-point of our study was to evaluate the efficacy of PEI on: 1) local symptomatology, assessed by an arbitrary symptom score; and 2) nodule volume and tracheal displacement (at ultrasonography). Follow-up ranged from 12-36 (21 +/- 9) months. Symptom score was significantly reduced (P < 0.01) after 6 months and at the end of the follow-up (2.1 +/- 0.3 vs. 0.2 +/- 0.5 and vs. 0.2 +/- 0.4). A significant (P < 0.01) nodule volume reduction was observed, without differences between solid or mixed CBNs; the reduction was 50% or more in 92.7% of patients. Neither clinical parameters nor pretreatment nodule ultrasonographic features were related to nodule reduction. Disappearance or significant reduction (>0.5 cm) of tracheal displacement was obtained in 61% and in 39% of patients, respectively. One patient experienced prethyroid region edema, pain, and mild fewer, which reversed within 1 week; and one patient had dysphonia, caused by vocal cord palsy, which reversed spontaneously within 1 month. At the end of the follow-up, nodules with just necrotic material at cytology showed a greater (P < 0.05) volume reduction than nodules with residual benign thyroid cells. Our data suggest that PEI is a safe and effective treatment of large CBNs, although sometimes serious side effects do occur.

Transition from cold to hot thyroid nodules

We report three cases of autonomously functioning thyroid nodules (AFTNs) that appeared hypofunctioning at radioactive iodine (131I) thyroid scan carried out at initial observation. Since at that time thyroid hormones and thyrotropin (TSH) were also normal, they were initially classified as "cold" nodules and treated with levothyroxine (LT4). The correct diagnosis of AFTN was made years later when a thyroid scintigraphy was repeated. In two of these patients, re-evaluation of the nodule was done because of the development of LT4 intolerance. A possible explanation is that these AFTNs had undergone hemorrhagic/cystic degeneration when they were first studied, but in subsequent years, proliferation of residual AFTN tissue caused the recurrence of a typical functioning nodule.

Changing concepts in the diagnosis and management of thyroid nodules

Thyroid nodules are extremely common, affecting from 4% to 7% of the population. Fine-needle aspiration biopsy is the most accurate and cost-effective technique for nodule diagnosis. It is simple, safe, and should be the first test used in patient work-up. Routine thyroxine (T4) suppressive therapy is no longer recommended for cytologically benign nodules. T4 suppression can cause or aggravate osteoporosis, especially in postmenopausal women. New data on T4 suppressive therapy, cost analysis, and nodule guidelines are reviewed.