Thyroid nodules and related symptoms are stably controlled two years after radiofrequency thermal ablation

BACKGROUND

Percutaneous radiofrequency thermal ablation (RTA) is a promising new therapeutic approach to manage thyroid nodules (TNs). The aim of this study was to investigate the long-term effectiveness of RTA in inducing shrinkage of TNs as well as in controlling compressive symptoms and thyroid hyperfunction in a large series of elderly subjects with solid or mainly solid benign TNs.

METHODS

Ninety-four elderly patients with cytologically benign compressive TNs were prospectively enrolled in the study; 66 of them had nontoxic goiter and 28 had toxic or pretoxic goiter. RTA was performed by using a RITA StarBurst Talon hook-umbrella needle inserted in every single TN under ultrasonographic real-time guidance. TN volume, TN-related compressive symptoms and thyroid function were evaluated at baseline and 12 to 24 months after RTA.

RESULTS

All TNs significantly decreased in size after RTA. The mean decrease in TN volume 12 months after RTA was from 24.5 +/- 2.1 to 7.5 +/- 1.2 mL (p < 0.001), with a mean percent decrease of 78.6 +/- 2.0%. Two years after RTA, a 79.4 +/- 2.5% decrease of TNs size was observed. Compressive symptoms improved in all patients and completely disappeared in 83 of 94 (88%) patients. Hyperthyroidism resolved in most patients allowing methimazole therapy to be completely withdrawn in 79% of patients with pretoxic and toxic TNs (100% with pretoxic TNs and 53% with toxic TNs). The treatment was well tolerated by all patients. No patient needed hospitalization after RTA and no major complications were observed.

CONCLUSIONS

RTA is an effective and simple procedure for obtaining lasting shrinkage of TNs, controlling compressive symptoms, and treating thyroid hyperfunction. When performed in experienced medical centers, RTA may be a valid alternative to conventional treatments for nontoxic and pretoxic TNs. It is particularly attractive for elderly people for whom surgery and radioiodine therapy are often contraindicated or ineffective.

Ultrasound-guided fine-needle aspiration biopsy of thyroid masses

The purpose of this study was to determine the impact of ultrasound-guided fine-needle aspiration biopsy (USFNA) in the cytological diagnosis of nodular thyroid disease. It remains unclear exactly what role USFNA should play in the cytological diagnosis of nodular thyroid disease. All patients who underwent fine-needle aspiration (FNA) for nodular thyroid disease at Stanford University Medical Center from 1991 to 1996 were included in the study. Histopathologic diagnoses were compared to cytological diagnoses for those patients who underwent surgery. FNA was performed on a total of 497 thyroid nodules. Palpation-guided FNA (pFNA) was performed on 370 nodules, and USFNA was done on 127. The USFNAs were performed for the following reasons: 95 (75%) for nonpalpable or difficult-to-palpate nodules; 14 (11%) for previously failed FNA; and 18 (14%) for incidentally detected nodules. FNA had an unsuccessful biopsy rate of 16% and a sensitivity and specificity of 89% and 69%, respectively. USFNA had an unsuccessful biopsy rate of 7% and a sensitivity and specificity of 100% and 100%, respectively. The cancer yield at surgery for pFNA was 40%, and the cancer yield at surgery for USFNA was 59%. The complementary use of USFNA with pFNA improves the diagnostic approach to nodular thyroid disease. The use of USFNA has increased the cancer yield at surgery and the sensitivity of thyroid biopsy at our institution.

Treatment of autonomous thyroid nodules with percutaneous ethanol injection: preliminary results. Work in progress

Eight patients with autonomous thyroid nodules 2.4-4.3 cm in diameter received percutaneous ethanol injections (PEIs) under guidance by means of ultrasound (US). Sterile ethanol at 95% was injected with a 22-gauge needle and a 7.5-MHz probe with a guide device. Each patient received one or two treatments, with 1-3 mL of alcohol (depending on the nodule size) per treatment, each week for a total of three to six injections per lesion. After a total of 36 injections in all eight patients, there were no complications. Follow-up ranged from 2 to 10 months. After therapy, symptoms subsided and hormonal levels became normal or reached the range of subclinical hypothyroidism. Scintigrams showed that the previously suppressed thyroid tissue had resumed functioning. At US, all nodules had shrunk. PEI was risk free and easy to perform. If these preliminary results are confirmed in a larger study with longer follow-up, the new treatment may become an alternative to surgical or radioiodine ablation of autonomous thyroid nodules.

Thyroid Tissue: US-guided Percutaneous Laser Thermal Ablation

PURPOSE

To evaluate in vivo the safety and effectiveness of percutaneous laser thermal ablation (LTA) in the debulking of thyroid lesions.

MATERIALS AND METHODS

Twenty-five adult patients at poor surgical risk with cold nodules (n = 8), autonomously hyperfunctioning thyroid nodules (n = 16), or anaplastic carcinoma (n = 1) underwent LTA. One to four 21-gauge spinal needles were inserted with ultrasonographic (US) guidance into the thyroid lesions. A 300-microm-diameter quartz optical fiber was advanced through the sheath of the needle. Nd:YAG laser was used with output power of 3-5 W. Side effects, complications, and clinical and hormonal changes were evaluated at the end of LTA and during follow-up. Linear regression analysis was used to investigate the correlation between energy delivered and reduction in nodule volume. Volume of induced necrosis and reduction in nodule volume were assessed with US or computed tomography.

RESULTS

LTA was performed without difficulties in 76 LTA sessions. After treatment with 5 W, two patients experienced mild dysphonia, which resolved after 48 hours and 2 months. Improvement of local compression symptoms was experienced by 12 of 14 (86%) patients. Thyroid-stimulating hormone (TSH) was detectable in five of 16 (31%) patients with hyperfunctioning nodules at 6 months after LTA. Volume of induced necrosis ranged from 0.8 to 3.9 mL per session. Anaplastic carcinoma treated with four fibers yielded 32.0 mL of necrosis. Echo structure and baseline volume did not influence response. Energy load and reduction in nodule volume were significantly correlated (r(2) =.75, P <.001). Mean nodule volume reduction at 6 months in hyperfunctioning nodules was 3.3 mL +/- 2.8 (62% +/- 21.4 [SD]) and in cold nodules was 7.7 mL +/- 7.5 (63% +/- 13.8).

CONCLUSION

LTA may be a therapeutic tool for highly selected problems in the treatment of thyroid lesions.

Quantification of Thyroid Cancer and Multinodular Goiter Risk in the DICER1 Syndrome: A Family-Based Cohort Study

CONTEXT

The risk of thyroid cancer and multinodular goiter (MNG) in DICER1 syndrome, a rare tumor-predisposition disorder, is unknown.

OBJECTIVE

To quantify the risk of thyroid cancer and MNG in individuals with DICER1 syndrome.

DESIGN

Family-based cohort study.

SETTING

National Institutes of Health (NIH) Clinical Center (CC).

PARTICIPANTS

The National Cancer Institute DICER1 syndrome cohort included 145 individuals with a DICER1 germline mutation and 135 family controls from 48 families.

INTERVENTIONS

Each individual completed a detailed medical history questionnaire. A subset underwent a 3-day evaluation at the NIH CC.

MAIN OUTCOME MEASURES

The cumulative incidence of MNG (or thyroidectomy) was quantified using the complement of the Kaplan-Meier product limit estimator. We compared the observed number of thyroid cancers in the NCI DICER1 cohort with matched data from the Surveillance, Epidemiology, and End Results (SEER) Program. We performed germline and somatic (thyroid cancer, MNG) DICER1 sequencing.

RESULTS

By the age of 40 years, the cumulative incidence of MNG or thyroidectomy was 75% in women and 17% in men with DICER1 syndrome compared with 8% of control women (P < 0.001) and 0% of control men (P = 0.0096). During 3937 person-years of observation, individuals with DICER1 syndrome had a 16-fold increased risk of thyroid cancer (95% confidence interval, 4.3 to 41; P < 0.05) compared with the SEER rates. Of 19 MNG nodules and 3 thyroid cancers, 16 (84%) and 3 (100%), respectively, harbored germline and somatic pathogenic DICER1 mutations.

CONCLUSIONS

We propose a model of thyroid carcinogenesis in DICER1 syndrome. Early-onset, familial, or male MNG should prompt consideration of the presence of DICER1 syndrome.

American Thyroid Association statement on optimal surgical management of goiter

BACKGROUND

Goiter, or benign enlargement of the thyroid gland, can be asymptomatic or can cause compression of surrounding structures such as the esophagus and/or trachea. The options for medical treatment of euthyroid goiter are short-lived and are limited to thyroxine hormone suppression and radioactive iodine ablation. The objective of this statement article is to discuss optimal surgical management of goiter.

METHODS

A task force was convened by the Surgical Affairs Committee of the American Thyroid Association and was tasked with writing of this article.

RESULTS/CONCLUSIONS

Surgical management is recommended for goiters with compressive symptoms. Symptoms of dyspnea, orthopnea, and dysphagia are more commonly associated with thyromegaly, in particular, substernal goiters. Several studies have demonstrated improved breathing and swallowing outcomes after thyroidectomy. With careful preoperative testing and thoughtful consideration of the type of anesthesia, including the type of intubation, preparation for surgery can be optimized. In addition, planning the extent of surgery and postoperative care are necessary to achieve optimal results. Close collaboration of an experienced surgical and anesthesia team is essential for induction and reversal of anesthesia. In addition, this team must be cognizant of complications from massive goiter surgery such as bleeding, airway distress, recurrent laryngeal nerve injury, and transient hypoparathyroidism. With careful preparation and teamwork, successful thyroid surgery can be achieved.

Ultrasonography: is it useful in the diagnosis of cancer in thyroid nodules?

The role of ultrasonography (US) in the diagnosis of cancer in thyroid nodules is not well-established. The aim of the present study was to evaluate US performance in predicting cancer in thyroid nodules using a novel approach. Two hundred and eighty-nine patients with thyroid nodular disease were evaluated with clinical, biochemical and cytopathological examinations. Eighty patients with palpable solitary thyroid nodules or multinodular goiters who were to undergo surgery were included, and had a US exam performed by one of us. Some US characteristics of thyroid nodules were associated to cancer: absent halo, hypoechogenicity and microcalcifications, with sensitivity, respectively, of 56, 44 and 56%, and specificity of, respectively, 80, 83 and 94%. These findings were considered positive and were studied in two different combinations: simultaneous, when two or more were positive, and parallel, when any positive finding was present. When positive findings were studied simultaneously, sensitivity ranged 25 to 38% and specificity ranged 89 to 97%. Microcalcifications, associated or not to other findings, were highly specific for thyroid cancer, but they were only present in half of the malignancies. When positive findings were studied in parallel, sensitivity ranged 69 to 81% and specificity ranged 70 to 81%. The parallel combination of hypoechogenicity or microcalcifications or absent halo improved US sensitivity to 81% with an acceptable specificity (70%). This method is potentially useful to help us select patients for surgery when fine-needle aspiration biopsy is repetitively non-diagnostic or select for biopsy incidentally discovered non-palpable nodules.

Evaluation of dosimetry of radioiodine therapy in benign and malignant thyroid disorders by means of iodine-124 and PET

The aim of this study was to evaluate the use of 124I positron emission tomography (PET) to determine the dosimetry of radioiodine therapy in hyperthyroidism and thyroid cancer. Phantom studies to assess the accuracy of PET were performed using an EEC phantom with spheres of different diameters filled with 3-30 MBq of 124I. Patient dosimetry was derived from PET data obtained 1-13 days after simultaneous oral administration of a therapeutic dose of 131I and a diagnostic dose of 124I. The obtained data were compared with findings from intratherapeutic probe measurements and clinical outcome. The phantom studies confirmed that 124I can be quantitated by PET (imprecision < or =10%), and volumetry is feasible for nodules <13 mm (imprecision < or =20%). Any influence of contamination with 123I or the simultaneous administration of 131I on the accuracy of the PET quantification and the probe measurements was ruled out by phantom measurements with solutions of 131I, 124I and 123I in various ratios. In autonomous nodular goitres, radioiodine uptake measured by PET varied from 25.4% to 64.3% and was not significantly different from that obtained by a scintillation probe (24.1%-73.1%, correlation coefficient r=0.91). Comparison of uptake and effective half-life in normal tissue versus autonomous nodules revealed significant differences in uptake but not in effective half-life [uptake 2.0-8.3 kBq/(ml x MBq) in normal tissue vs 12.6-29.3 kBq/(ml x MBq) in nodules; half-life 97.8-156.7 h in normal tissue vs 73.3-192.3 h in nodules]. Calculated radiation doses ranged between 177 and 633 Gy for autonomous nodules and between 47 and 126 Gy for normal tissue. In thyroid cancer patients, doses between 350 and 1,420 Gy were achieved in thyroid remnants and between 70 and 170 Gy in tumour metastases. It is concluded that 124I and PET are suitable for evaluation of the dosimetry of radioiodine therapy in benign and malignant thyroid diseases. The applied technique might be particularly useful for quantitative dose-response studies in radioiodine treatment and further investigations of stunning phenomena.

Ultrasound-guided laser thermal ablation in the treatment of autonomous hyperfunctioning thyroid nodules and compressive nontoxic nodular goiter

OBJECTIVE

Percutaneous laser thermal ablation (LTA) has been applied in several tumors. In this study we evaluated the safety and long-term efficacy of LTA in the treatment of benign thyroid nodules.

DESIGN AND PATIENTS

Seven patients with autonomous hyperfunctioning thyroid nodule (group A) and five patients with compressive nodular goiter (group B) were treated with LTA. Up to three needles were positioned centrally in the thyroid nodule and laser fiber was placed in the lumen of the needle. Laser illumination was performed reaching a maximal energy deposition of 1800 J per fiber.

MEASUREMENTS

Thyroid nodule volume, endocrinologic, and clinical evaluation were performed at baseline, 3, and 12 months after the treatment. Scintigraphy was performed at diagnosis and 12 months after the first session in group A.

RESULTS

In group A, mean thyroid volume decreased from 3.15 +/- 1.26 mL to 0.83 +/- 0.49 mL (p < 0.001) after 12 months. The treatment induced disappearance of clinical signs and symptoms related to hyperthyroidism; normalization of free triiodothyronine (FT(3)), free thyroxine (FT(4)), and thyrotropin (TSH) serum levels and recovery of extranodular uptake at scintiscan. In group B, mean thyroid volume decreased from 11.14 +/- 4.99 mL to 3.73 +/- 1.47 mL (p < 0.01) after 12 months. Pressure symptoms in the neck, difficulty in swallowing and tracheal displacement improved in all patients. The treatment was well tolerated in both groups of patients.

CONCLUSIONS

LTA appears to be a valid and safe alternative approach in the treatment of benign thyroid nodules.

The use of fine-needle aspiration biopsy under ultrasound guidance to assess the risk of malignancy in patients with a multinodular goiter

PURPOSE

Fine-needle aspiration biopsy (FNAB) is a commonly performed procedure used in the evaluation of solitary thyroid nodules, in which the risk of malignancy is approximately 5% in most patients. Recently, the use of ultrasound (US) guidance in FNAB has been shown to enhance the diagnostic efficacy of this procedure. However, the risk of malignancy in thyroid nodules occurring within a multinodular goiter (MNG) has not been completely clarified, nor has the optimal means of investigating such nodules using FNAB.

SUBJECTS AND METHODS

We performed a retrospective study of all patients seen over a 4-year period with a MNG that had one or more nodules who underwent FNAB under US guidance. The results from the history and physical examination, thyroid function and antibody tests, radionuclide studies, thyroid sonogram, cytology of aspirated nodules, and surgical pathology were recorded and analyzed.

RESULTS

A total of 93 nodules were aspirated in 61 patients with MNG. Adequate material was obtained in 96% of aspirates on the first attempt. Sixty-seven aspirates in 44 patients yielded benign cytology and 22 aspirates in 15 patients yielded suspicious cytology. All patients with suspicious cytology underwent thyroid surgery. Thyroid cancer was found in 5 of these nodules, including 4 cases of papillary cancer and 1 case of Hürthle cell cancer, and 1 additional patient had occult papillary cancer discovered. The overall malignancy rate in thyroid nodules among the patients with MNG was approximately 5%.

CONCLUSIONS

FNAB under US guidance is a useful diagnostic modality in the evaluation of thyroid nodules in selected patients with MNG. Because the risk of thyroid malignancy in these nodules is comparable to that which exists in solitary thyroid nodules, the possibility of thyroid malignancy should be considered in all patients with MNG.

Pretreatment with a single, low dose of recombinant human thyrotropin allows dose reduction of radioiodine therapy in patients with nodular goiter

In patients with nodular goiter, radioiodine ((131)I) therapy results in a mean reduction in thyroid volume (TV) of approximately 40% after 1 yr. We have demonstrated that pretreatment with a single, low dose of recombinant human TSH (rhTSH) doubles 24-h radioactive iodine uptake (RAIU) in these patients. We have now studied the safety and efficacy of therapy with a reduced dose of (131)I after pretreatment with rhTSH. Twenty-two patients with nodular goiter received (131)I therapy, 24 h after im administration of 0.01 (n = 12) or 0.03 (n = 10) mg rhTSH. In preceding diagnostic studies using tracer doses of (131)I, 24-h RAIU without and with rhTSH pretreatment (either 0.01 or 0.03 mg) were compared. Therapeutic doses of (131)I were adjusted to the rhTSH-induced increases in 24-h RAIU and were aimed at 100 micro Ci/g thyroid tissue retained at 24 h. Pretreatment with rhTSH allowed dose reduction of (131)I therapy by a factor of 1.9 +/- 0.5 in the 0.01-mg and by a factor of 2.4 +/- 0.4 in the 0.03-mg rhTSH group (P < 0.05, 0.01 vs. 0.03 mg rhTSH). Before and 1 yr after therapy, TV and the smallest cross-sectional area of the tracheal lumen were measured with magnetic resonance imaging. During the year of follow-up, serum TSH, free T(4) (FT(4)), T(3), and TSH receptor antibodies were measured at regular intervals. TV before therapy was 143 +/- 54 ml in the 0.01-mg group and 103 +/- 44 ml in the 0.03-mg rhTSH group. One year after treatment, TV reduction was 35 +/- 14% (0.01 mg rhTSH) and 41 +/- 12% (0.03 mg rhTSH). In both groups, smallest cross-sectional area of the tracheal lumen increased significantly. In the 0.01-mg rhTSH group, serum FT(4) rose, after (131)I treatment, from 15.8 +/- 2.8 to 23.2 +/- 4.4 pM. In the 0.03-mg rhTSH group, serum FT(4) rose from 15.5 +/- 2.5 to 23.5 +/- 5.1 pM. Individual peak FT(4) levels, reached between 1 and 28 d after (131)I treatment, were above the normal range in 12 patients. TSH receptor antibodies were negative in all patients before therapy and became positive in 4 patients. Hyperthyroidism developed in 3 of these 4 patients between 23 and 25 wk after therapy. In conclusion, in patients with nodular goiter pretreatment with a single, low dose of rhTSH allowed approximately 50-60% reduction of the therapeutic dose of radioiodine without compromising the efficacy of TV reduction.

Long-term changes in nodular goiter: a 5-year prospective randomized trial of levothyroxine suppressive therapy for benign cold thyroid nodules

We studied for 5 yr a homogeneous group of 83 patients randomly assigned to a levothyroxine (L-T4) suppressive therapy or to a control group to evaluate changes in nodule or thyroid size, appearance of new nodules, and correlations with clinical parameters. In the control group, mean nodule volume increased significantly after 5 yr (2.12 +/- 1.46 vs. 1.46 +/- 0.77 mL), whereas in the treatment group it decreased, although not significantly (1.45 +/- 1.17 mL vs. 1.53 +/- 0.61 mL). Baseline nodule volume was not different in the two groups, but a significant difference was observed at 5 yr. After 5 yr, sonograms detected 12 new nodules in the control group (28.5%) and 3 (7.5%) in the treatment group. Nodule shrinkage was more frequent in patients with complete TSH suppression, but no correlation was found with other parameters. A significant increase in thyroid size was observed in the control group. In conclusion, long term TSH suppression induced volume reduction in only a subgroup of thyroid nodules, but effectively prevented the appearance of new lesions and increases in nodule and thyroid volume. As the changes in the natural history of nodular goiter are related to prolonged TSH suppression, which can induce unfavorable side-effects, L-T4 suppressive therapy should be reserved for small nodules in younger patients.

Comparison among sonography, double-tracer subtraction scintigraphy, and double-phase scintigraphy in the detection of parathyroid lesions

OBJECTIVE

This study prospectively evaluated the sensitivity of high-resolution sonography compared with double-tracer 201Tl-99mTc scintigraphy (Tl-Tc) subtractive scintigraphy and double-phase 99mTc-sestamibi (Tc-MIBI) scintigraphy prior to surgery in the assessment of patients with primary hyperparathyroidism in a geographic region where areas of endemic thyroid goiter are present.

SUBJECTS AND METHODS

Sonography and scintigraphy were used as first-step imaging procedures in 73 patients with primary hyperparathyroidism. In 30 (41%) of 73 cases, we found an association with a thyroid abnormality. We compared sonography with double-tracer Tl-Tc scintigraphy in 41 cases, with Tc-MIBI scintigraphy in 22 other cases, and with both scintigraphic studies in 10 other cases.

RESULTS

Surgery demonstrated 68 solitary parathyroid lesions (66 adenomas, one hyperplasia, and one carcinoma), two adenomas in two patients, and multiple hyperplastic glands in two patients for a total of seven lesions. In one case no abnormal parathyroid gland was found. Overall sensitivity of sonography, Tl-Tc, and Tc-MIBI scintigraphy was 85%, 62%, and 82%, respectively. In patients with concomitant thyroid disease, the sensitivity of sonography, dual-tracer Tl-Tc, and Tc-MIBI was 77%, 67%, and 80%, respectively.

CONCLUSION

Our study proves that sonography and scintigraphy are equally able to detect parathyroid lesions before surgery in patients with concomitant thyroid diseases. In patients without thyroid abnormalities, detection rates of sonography and Tc-MIBI do not show any statistical difference, and the detection rate of Tl-Tc is significantly inferior to that of sonography. Sonography alone should be used as the first step for localization of abnormal parathyroid glands prior to surgery, and Tc-MIBI scintigraphy should be used as the second step when sonography is negative.

The spectrum of thyroid disorders in an iodine-deficient community: the Pescopagano survey

We carefully assessed thyroid status and goiter by ultrasound in 1411 subjects virtually representing the entire resident population of Pescopagano, an iodine-deficient village of Southern Italy. Median urinary iodine excretion was 55 microg/L. The prevalence of goiter was 16.0% in children and 59.8% in adults. Thyroid nodularity was 0.5% in children and progressively increased with age to 28.5% in the 56- to 65-yr-old group. The prevalence of present or past hyperthyroidism was 2.9%, including 9 cases with toxic diffuse goiter and 20 with toxic nodular goiter. Functional autonomy was rare in children, progressively increased with age up to 15.4% in the elderly, and was related to nodular goiter. The prevalences of overt and subclinical hypothyroidism in the adults were 0.2% and 3.8%, respectively. Serum autoantibodies to thyroglobulin and thyroperoxidase were detected in 12.6% of the entire population. The prevalence of diffuse autoimmune thyroiditis was 3.5%, being very low in children. Thyroid cancer was found in only 1 case. In conclusion, in the present survey of an iodine-deficient community, a progressive increase with age of goiter prevalence, thyroid nodularity, and functional autonomy was observed. Hyperthyroidism was twice as high as that reported in iodine-sufficient areas, mainly due to an increased frequency of toxic nodular goiter. Although low titer serum thyroid antibodies were relatively frequent, the prevalences of both overt and subclinical autoimmune hypothyroidism were not different from those observed in iodine-sufficient areas.

Diagnosis of Thyroid Cancer in Children: Value of Gray-Scale and Power Doppler US

PURPOSE

To prospectively analyze the accuracy of various diagnostic criteria for cancer in solid thyroid nodules in children on the basis of gray-scale and power Doppler ultrasonographic (US) findings.

MATERIALS AND METHODS

The study protocol was approved by the institutional review board, and patient's parents gave full informed consent. One hundred three consecutive pediatric patients with solid thyroid nodules were included in the study. Thirty-five patients had thyroid cancer (mean age, 14.6 years +/- 2.6 [standard deviation]; range, 10-18 years), and 68 patients had benign thyroid nodules (mean age, 14.2 years +/- 2.9; range 9-18 years). Three-dimensional US was used to determine the volume of thyroid gland and thyroid nodules. Results of nodule cytologic and histologic examination and long-term clinical and US follow-up were used as a proof of final diagnosis. The following US characteristics were evaluated: location, echogenicity, echotexture, outline, presence of a halo, microcalcifications, and type of vascularization. Multivariate logistic regression analysis was used to evaluate the accuracy of US criteria for thyroid cancer in lesions with diameter of 15 mm and smaller and lesions with diameter larger than 15 mm. Qualitative variables were compared by using the chi(2) test and quantitative variables were compared by using the Student t test. Significance was defined at P < .05.

RESULTS

In thyroid nodules with diameter of 15 mm and smaller, the most reliable diagnostic criteria for malignancy were an irregular outline (sensitivity, 69.6%; specificity, 86.4%; P < .001), subcapsular location (sensitivity, 65.2%; specificity, 86.4%; P < .001), and increased intranodular vascularization (sensitivity, 69.6%; specificity, 87.9%; P < .01). For thyroid nodules larger than 15 mm in diameter, the accuracy of US diagnosis was much lower than that for smaller nodules. The only reliable criterion for cancer in this group was hypoechogenicity (sensitivity, 60.0%; specificity, 84.0%; P < .01).

CONCLUSION

Study findings indicate that US is most helpful in diagnosis of thyroid malignancy in thyroid nodules with diameter of 15 mm and smaller, with detection of irregular tumor outline, subcapsular location, and increased intranodular vascularization.

Interrelationships between age, thyroid volume, thyroid nodularity, and thyroid function in patients with sporadic nontoxic goiter

PURPOSE

To test the hypothesis that during the natural history of sporadic nontoxic goiter (SNG), a diffuse goiter precedes a multinodular goiter with gradual development of autonomous thyroid function.

PATIENTS AND METHODS

A cross-sectional survey of 102 consecutive patients with SNG (seven male, 95 female) was performed. Thyroid volume was measured by ultrasonography, and plasma thyroid-stimulating hormone (TSH) by a sensitive assay (TSH immunoradiometric assay).

RESULTS

Patients with a multinodular goiter were older and had a larger thyroid volume than patients with a diffuse or uninodular goiter. Plasma free thyroxine (T4) and total triiodothyronine (T3) were higher and plasma TSH was lower in patients than in normal subjects. Free T4 was higher in the subgroup of patients with a multinodular goiter and a decreased TSH response to thyrotropin-releasing hormone. Plasma TSH (y, in mU/L) was negatively related to thyroid volume (x, in mL): y = 8.2x-0.667 (r = 0.578, p less than 0.001). Thyroid volume (y, in mL) was positively related to age (x, in years): y = -21.8 + 2.0x (r = 0.455, p less than 0.001); and to duration of goiter (x, in years): y = 40.6 + 2.1x (r = 0.505, p less than 0.001). The annual increase in thyroid volume was calculated at 4.5%.

CONCLUSION

The data suggest a continuous growth of SNG and provide support for the concept of increasing thyroid nodularity and autonomy of thyroid function--related to increasing thyroid volume--during the natural history of this disorder.

Levothyroxine suppressive therapy is partially effective in treating patients with benign, solid thyroid nodules and multinodular goiters

We prospectively evaluated the effect of thyrotropin (TSH)-suppressive therapy with levothyroxine (LT4) on the size of a benign, solitary, solid nodule and multinodular goiter in a relatively low iodine intake area. In this study, 101 euthyroid subjects with a benign, solitary, predominantly solid nodule (n = 54) confirmed by biopsy or multinodular goiter (n = 47) received 200 microg of levothyroxine daily as a single morning tablet for 12 months. Thirty-five receiving no therapy were considered as controls (solitary nodules, n = 20, multinodular, n = 15). Patients were admitted to the study after evaluation of thyroid biochemical parameters (thyroxine [T4], free thyroxine [FT4], triiodothyronine [T3], thyrotropin [TSH], and thyroglobulin [Tg]), thyroid scanning, ultrasound examination, and fine-needle aspiration biopsy. Every 3 months, thyroid function tests and every 6 months ultrasound examinations were repeated. Twelve months later 20 of 54 (37.1%) patients with single, solid nodules had 50% or more regression of the nodular volume (responders). Eleven of 54 (20.3%) patients had more than 20%, but less than 49.9% reduction of nodular volume (partial responders). Nonresponders were 23 of 54 (42.5%). One-third of subjects with multinodular goiter had 50% or more regression of the glandular volume, whereas 46.8% were considered as nonresponsive. The mean serum Tg levels decreased significantly only in responders with solitary nodular disease or multinodular goiter. In the control group only 1 patient (5% of total) with a solitary nodule had a 50% reduction in the nodular volume. Five others had a partial response (<49%, >20% reduction). None of the patients with multinodular goiter had a significant reduction (>50%) of the combined nodular volumes. We concluded that LT4 may be effective, among other factors, in arresting the growth or in reducing the volume of relatively small, benign, solitary, solid thyroid nodules or the combined nodular volume of multinodular goiter.

Epidemiology of nodular goitre. Influence of iodine intake

More than one tenth of the world population is to some degree affected by goitre and most of these harbour nodules. The large differences in thyroid disease prevalence between populations may be caused by genetic and environmental factors. Among the latter, iodine deficiency seems by far to be the most important risk factor. Thus, nodular goitre is a condition predominantly seen in iodine deficient areas of the world. In the present review, we evaluated in detail autopsy and ultrasound studies of the thyroid gland. In autopsy studies, large thyroid volumes and high frequencies of goitres have been reported in countries affected by iodine deficiency. Many cross-sectional studies using thyroid ultrasound investigations have been performed world-wide and reported high thyroid volumes and goitre prevalences, and to some extent also high prevalences of thyroid nodules in iodine-deficient countries. Most of these goitres were classified as nodular goitres. On the other hand, few studies have shown that abundant iodine intake may lead to development of diffuse goitres, but world-wide this has been a minor problem compared with development of nodular goitres. In the past century we have observed a trend towards smaller thyroid glands, and hopefully less than 10% of the world population will experience goitre within a few decades.

Comparative scanning of thyroid nodules with technetium-99m pertechnetate and technetium-99m methoxyisobutylisonitrile

Thyroid imaging was performed using technetium-99m methoxyisobutylisonitrile and technetium-99m pertechnetate in 58 patients. The 99mTc-pertechnetate scans showed a total of 77 nodules: 60 cold, 13 hot and 4 of normal activity. There was no 99mTc-MIBI accumulation in 46.4% of 99mTc-pertechnetate cold nodules; 27 (45%) of these nodules showed 99mTc-MIBI uptake with the same intensity as the surrounding normal tissue, and five (8.6%) became hot with 99mTc-MIBI. Of the 99mTc-pertechnetate hot nodules 11 (84.6%) could not be differentiated from the normal extranodular tissue on the 99mTc-MIBI scan. The histopathology of 34 surgically removed nodules proved that increased, normal or decreased 99mTc-MIBI accumulation is not specific for thyroid malignancy and that the 99mTc-MIBI uptake depends mainly on the viability of thyroid tissue.

Approach to the patient with nontoxic multinodular goiter

Thyroid nodules are very common, and although the majority are benign, approximately 5% may harbor malignancy. The evaluation of the patient with solitary thyroid nodule is generally straightforward and will typically include measurement of serum TSH to assess thyroid function and fine-needle aspiration biopsy of the nodule, with or without ultrasound (US) guidance. The approach to the patient with nontoxic multinodular goiter represents a more difficult problem for the clinician. All patients should have serum TSH measured to assess functional thyroid status and US examination to evaluate the number, size, and sonographic features of the nodules and assist in the selection of nodules that may need fine-needle aspiration biopsy. Patients with nodules yielding malignant cytology should be referred for surgery. Given the lack of reliable markers to predict biological behavior of nodules with suspicious (indeterminate) cytology, patients with such nodules are generally advised to have surgery, unless autonomous function of these nodules can be confirmed by scintigraphy. Most of these patients, however, will ultimately prove to have benign follicular tumors. Many patients with benign but large goiters may experience clinical symptoms of pressure, such as dysphagia, choking sensation, or airway obstruction. Such patients will often require surgery for alleviation of symptoms. In the absence of malignancy, asymptomatic patients may be observed. Radioactive iodine, commonly used in many parts of Europe, is safe and effective and may be a reasonable option for many patients. Periodic follow-up with neck palpation and US exam is recommended for all patients.

Acute changes in thyroid volume and function following 131I therapy of multinodular goitre

OBJECTIVE

Many textbooks claim that radioiodine (131I) treatment should be given with care to a goitre with substernal extension, for fear of acute swelling of the gland and thus respiratory problems. Since 131I is used increasingly in the treatment of non-toxic as well as toxic goitre we have evaluated the acute changes in thyroid volume following 131I therapy.

DESIGN

Evaluation of potential acute changes in thyroid volume and function after 131I treatment in patients with non-toxic goitre treated because of compression symptoms or for cosmetic reasons, as well as in patients with toxic goitre.

PATIENTS

Out-patients with multinodular goitre, either non-toxic (n = 20) or toxic (n = 10). Excluded were patients with a substernal goitre.

MEASUREMENTS

Ultrasonically determined thyroid volume and standard thyroid function variables were investigated before and 2, 7, 14, 21, 28 and 35 days after treatment.

RESULTS

In non-toxic goitres the thyroid volume did not increase significantly, the maximum increase in the median volume being 4% on day 7. Serum levels of free T3 and free T4 indices increased by 20% (day 7) and 13% (day 14) (P = 0.002), respectively. Likewise thyroid volume in toxic nodular goitre did not change significantly after 131I treatment (maximum median increase was 2%). None of the patients presented symptoms of tracheal compression.

CONCLUSIONS

131I treatment of non-toxic as well as toxic multinodular goitre does not seem to increase thyroid volume.

Pretreatment with recombinant human TSH changes the regional distribution of radioiodine on thyroid scintigrams of nodular goiters

In a recent study, we demonstrated that pretreatment with a single, low dose of recombinant human TSH (rhTSH) doubles 24-h thyroid radioactive iodine uptake in patients with nodular goiter. The purpose of the present study was to investigate whether rhTSH pretreatment induces changes in the regional distribution of radioiodine as visualized on thyroid scintigrams in these patients. Anterior planar thyroid 123I scintigrams were obtained in 26 patients with a nodular goiter (23 women and 3 men; age, 62 +/- 9 yr, mean +/- SD; thyroid weight, 165 +/- 72 g) 24 h after administration of a diagnostic dose of radioiodine. All patients were studied twice: first, without rhTSH pretreatment (baseline study), and second, after an im injection of 0.01 mg (n = 10) or 0.03 mg rhTSH (n = 16), given 24 h before radioiodine administration (rhTSH study). For quantification of regional differences in radioiodine uptake, a region of interest method was used. Upon visual inspection, baseline scintigrams showed a heterogeneous uptake of radioiodine. In general, rhTSH scintigrams also showed heterogeneous radioiodine uptake. In some patients, the distribution of radioiodine in the rhTSH scintigram was considerably more homogeneous than in the baseline scintigram. In a few patients, originally "cold" areas had changed into "hot" ones, whereas originally hot areas had changed into cold ones. Quantification of regional radioiodine uptake showed that pretreatment with rhTSH caused a larger increase in radioiodine uptake in relatively cold areas and a smaller increase in radioiodine uptake in relatively hot areas, compared with the increase in radioiodine uptake in the entire thyroid. In patients with a baseline serum TSH level of 0.5 mU/liter or lower, the increase in radioiodine uptake in relatively cold areas was significantly larger than in patients with a baseline serum TSH level higher than 0.5 mU/liter. In conclusion, a single, low dose of rhTSH not only doubled 24-h radioactive iodine uptake but also caused a more homogeneous distribution of radioiodine within the thyroid gland in patients with a nodular goiter by stimulating radioiodine uptake in relatively cold areas more than in relatively hot areas. This was most marked in patients with a low baseline serum TSH level. Our data suggest that pretreatment with rhTSH may improve the efficacy of radioiodine treatment for volume reduction of nodular goiters, especially in patients with a low baseline serum TSH level.

Stimulation With 0.3-mg Recombinant Human Thyrotropin Prior to Iodine 131 Therapy to Improve the Size Reduction of Benign Nontoxic Nodular Goiter

BACKGROUND

Use of recombinant human thyrotropin increases the thyroid radioiodine (iodine 131 [(131)I]) uptake and may have a role in the context of (131)I therapy of benign goiter.

METHODS

In a double-blind, placebo-controlled trial, 57 patients with nodular nontoxic goiter (51 women and 6 men) were randomized to receive either 0.3 mg of recombinant human thyrotropin (n = 28) or placebo (n = 29) 24 hours before (131)I therapy. The (131)I dose was calculated based on thyroid size (measured by ultrasound), thyroid (131)I uptake, and (131)I half-life. The follow-up period was 1 year and included measurements of thyroid size and function and patient satisfaction.

RESULTS

Baseline median goiter volume was 51 mL (range, 20-99 mL) in the placebo group and 59 mL (range, 25-92 mL) in the thyrotropin group (P = .75). At 12 months, the mean +/- SEM relative goiter reduction was 46.1% +/- 4.0% in the placebo group and 62.1% +/- 3.0% in the thyrotropin group (P = .002 between groups). The difference was most pronounced among patients with large goiters. Within each group, there was no significant correlation between retained thyroid (131)I dose and goiter reduction. Adverse effects were significantly more frequent in the thyrotropin group (34 vs 12 events; P<.001). Permanent hypothyroidism developed in 3 patients (11%) in the placebo group compared with 16 patients (62%) in the thyrotropin group (P<.001). Patient satisfaction was high and uninfluenced by the use of recombinant human thyrotropin.

CONCLUSIONS

Stimulation with recombinant human thyrotropin prior to (131)I therapy improves thyroid size reduction by 35%, with a 5-fold higher rate of hypothyroidism. These effects are, at least partially, mediated through mechanisms other than an increase in retained (131)I thyroid dose. Further recombinant human thyrotropin dose-finding studies are warranted before routine use.

Radioiodine for nontoxic multinodular goiter

Surgery is considered standard therapy for nontoxic goiter. However, surgical treatment of large goiters is not without risk, especially in elderly patients and in those with cardiopulmonary diseases. Therefore, in recent years interest in 131I treatment of nontoxic goiter has increased. Studies, using ultrasonography and magnetic resonance imaging (MRI) for accurate measurements of thyroid volume, have shown that 131I treatment of nontoxic nodular goiter results in a mean thyroid volume reduction of 40% after 1 year of 50-60% after 3-5 years. Moreover, an improvement of compressive symptoms can be achieved. This has been objectified by a significant decrease in tracheal compression as measured by MRI. Early side effects due to radiation thyroiditis usually are mild. The development of autoimmune hyperthyroidism occurring several months after 131I therapy in approximately 5% of patients is the most important complication of 131I therapy for nontoxic goiter. The incidence of post-treatment hypothyroidism appears to be approximately 20-30% at 5 years. For elderly people, the lifetime risk of fatal and nonfatal cancer induced by this therapy (administered activity 1.9 +/- 0.9 GBq of 131I) was estimated to be approximately 0.5%. In all patients with nontoxic multinodular goiter the estimated risks of both surgery and radioiodine therapy should be weighed carefully. In younger patients surgery still is to be preferred, especially when the amount of 131I to be administered is high. However, for elderly patients, especially those with cardiopulmonary disease, the profits of radioiodine treatment will outweigh the lifetime risk of this mode of therapy.

Recombinant human thyrotropin as adjuvant in the treatment of multinodular goiters with radioiodine

The use of 131I in the treatment of multinodular goiters (MNG) is well established. We evaluated the effect of 30 microCi 131I (1.11 GBq) in 18 patients with MNG with the aid of two injections of 0.1 mg recombinant human TSH (rhTSH), given on d 1 and 2. A dose of 30 microCi 131I was given on d 3. TSH, T3, free T4, and thyroglobulin were measured on d 1, 2, 3, 5, 10, 30, 60, 90, and 180, and antithyroid antibodies were measured on d 1, 30, 90, and 180. Twenty-four-hour 131I uptake measured 1-3 months before rhTSH increased from 12.3 +/- 6.2 to 53.5 +/- 10.9% (P < 0.0001), free T4 from 1.3 +/- 0.2 to peak 3.2 +/- 1.1 ng/dl levels (P < 0.0001), T3 from 113.9 +/- 35.0 to peak 332.2 +/- 123.0 ng/dl levels (P < 0.0001), TSH from 0.76 +/- 0.71 to peak 18.9 +/- 5. 3 mU/liter levels (P < 0.0001), and thyroglobulin from 280.9 +/- 370.0 to peak 1838.5 +/- 1360.7 ng/dl levels (P = 0.001). Painful thyroiditis (33%) and mild thyrotoxicosis (39%) constituted minor side effects. There were no changes in echocardiographic parameters, done before and after rhTSH administration, on d 3. Hypothyroidism developed in 65%. Mean goiter size, measured by computed tomography, decreased from 97.9 +/- 45.4 to 65.5 +/- 47.3 ml (P < 0.0001; reduction: 39 +/- 19%) after 6 months. We conclude that rhTSH is a safe and efficient therapeutic tool in the treatment of MNG allowing the use of outpatient therapeutic 131I doses.