Diagnosis of neck recurrences in patients with differentiated thyroid carcinoma

Ultrasound features of suture granulomas in the thyroid bed after thyroidectomy for papillary thyroid carcinoma with an emphasis on their differentiation from locally recurrent thyroid carcinomas

The purpose of our study was to evaluate the ultrasound features of suture granulomas at the thyroid bed after thyroidectomy for papillary thyroid carcinoma with an emphasis on their differentiation from locally recurrent thyroid carcinomas. We enrolled 14 suture granulomas in 10 patients and 20 locally recurrent carcinomas in 18 patients after thyroidectomy, confirmed by surgery (15 out of 20 recurrent carcinomas), or ultrasound-guided fine needle aspiration cytology (14 suture granulomas and 5 recurrent carcinomas). The ultrasound findings, including presence of internal echogenic foci suggesting calcification or suture material, were compared between the two groups. In the cases with internal echogenic foci, the size, number, distribution pattern, and the presence of a paired appearance were also evaluated. In result, most of the suture granulomas were irregular (n=13) and heterogeneous (n=9) (p<0.05). The incidence of internal echogenic foci was higher in suture granulomas (n=12) than in recurrent carcinomas (n=7) (p<0.05). The internal echogenic foci in all suture granulomas were clustered centrally or paracentrally, unlike those in recurrent carcinomas (p<0.05). Most of the echogenic foci in suture granulomas were larger than 1 mm in diameter (p<0.05) and had a paired appearance (p<0.05). Shape, heterogeneity, and the presence of central or paracentral internal echogenic foci are helpful criteria for differentiating suture granulomas from locally recurrent tumors in the thyroid bed.

Sonographic features of traumatic neuromas after neck dissection

PURPOSE

To evaluate the sonographic features of traumatic neuromas after neck dissection.

METHODS

This study included 8 patients whose ages ranged from 36-69 years (mean, 49 years). In all cases, traumatic neuromas were incidentally detected at neck sonography for evaluation of suspected recurrence of well-differentiated papillary carcinoma of the thyroid. All sonograms and medical records were retrospectively reviewed.

RESULTS

This study covered 8 cases in which traumatic neuromas were diagnosed by clinical, laboratory, fine-needle aspiration biopsy (FNAB), and other imaging modalities. None of the patients had clinical signs of neuromas, which were, incidentally, discovered by neck sonography. A noticeable sonographic feature in all cases was an isoechoic mass with internal parallel heterogeneous hyperechogenicity. All patients complained of severe pain during FNAB. The cytological results of 2 patients showed fragments of nerve tissue. The remaining 6 FNABs were nondiagnostic. Thyroglobulin (Tg) levels in washout fluids from FNAB of all patients were <0.2 ng/mL, indicating nonthyroidal origin.

CONCLUSION

Distinctive sonographic features, sharp pain during FNAB, and low Tg levels in FNAB washout fluid can help to diagnose traumatic neuromas without surgery.

Diagnostic and therapeutic use of recombinant human TSH (rhTSH) in differentiated thyroid cancer

Traditionally, withdrawal of thyroid hormone to increase serum levels of thyroid-stimulating hormone (TSH) has been used in patients with differentiated thyroid carcinoma (DTC) to optimize radio-iodine uptake and serum thyroglobulin (Tg) stimulation during follow-up and in preparation for radio-iodine therapy. However, this procedure is associated with signs and symptoms of hypothyroidism which negatively affect the patient's quality of life. Recombinant human thyrotropin (rhTSH) has provided an effective alternative to thyroid hormone withdrawal. After favourable experimental trials in humans, rhTSH obtained regulatory approval in North America and in Europe as a diagnostic tool, and more recently as a preparation for radio-iodine thyroid remnant ablation. Since then, rhTSH has radically changed the diagnostic and therapeutic management of DTC patients. This review will focus on the clinical application of rhTSH in the management of DTC, highlighting current indications and future perspectives.

Serum thyroglobulin determination in thyroid cancer patients

Serum thyroglobulin determination plays a central role, in combination with neck ultrasonography, in the follow-up of thyroid cancer patients. Its specificity is improved by thyroid remnant ablation, and its sensitivity is optimal following prolonged withdrawal or stimulation with recombinant human thyroid-stimulating hormone (TSH). Modern methods with an improved functional sensitivity may facilitate its use during follow-up.

Predictors of level V metastasis in well-differentiated thyroid cancer

BACKGROUND

Cervical lymphadenectomy is frequently performed in patients with lateral cervical lymph node metastases to improve regional control of disease. However, there is no consensus regarding the appropriate levels of the neck that need to be dissected. Treatment options that have been advocated include the modified radical neck dissection, limited neck dissections, and selective nodal excisions. In particular, the routine dissection of level V remains controversial due to the attendant morbidity to the spinal accessory nerve. To identify clinical and pathological predictors of cervical node metastases to level V in differentiated thyroid carcinoma, we reviewed our experience at The University of Texas M. D. Anderson Cancer Center for the management of metastatic well-differentiated thyroid cancer.

METHODS

We retrospectively analyzed 70 patients who underwent thyroidectomy and neck dissection for well-differentiated thyroid cancer at M. D. Anderson Cancer Center.

RESULTS

In our series, 53% of neck specimens harbored metastatic thyroid carcinoma at level V. Additionally, 13 level V contralateral neck dissections were performed, and 57% were found positive for metastases. The presence of ipsilateral level V metastases was significantly associated with multifocal disease (p <.05), ipsilateral level II (p <.05), III (p <.05), or IV (p <.01) metastases. Furthermore, ipsilateral involvement of level V was associated with contralateral lymph node metastases (p <.05). Age, sex, and size of primary tumor were not found to be associated with level V metastases. Additionally, preoperative imaging was not sensitive for detecting the presence of level V metastases.

CONCLUSION

In our series, cervical metastases from differentiated thyroid carcinoma were commonly present at level V. Patients with multifocal cancer within the thyroid gland, and cervical metastases in the ipsilateral jugular nodes have a higher risk of harboring metastatic disease at level V. We believe that routine dissection of the level V lymph nodes should be performed in the setting of a comprehensive neck dissection for patients with lateral neck metastasis from well-differentiated thyroid cancer.

Predictive value of recombinant human TSH stimulation and neck ultrasonography in differentiated thyroid cancer patients

BACKGROUND

Serum thyroglobulin (Tg) stimulation by recombinant human TSH (rhTSH), in combination with neck ultrasonography (US), is an important tool in the first follow-up of differentiated epithelial cell thyroid carcinoma (DTC) patients. The objective of this study was to investigate if a second rhTSH stimulation, performed 2-3 years later, is of clinical utility in the follow-up of these patients.

METHODS

One hundred and one consecutive ambulatory DTC patients were studied. The great majority of them (89/101) were low-risk patients, being stage I or II at tumor node metastasis (TNM) staging classification. All study patients had been treated by surgery and radioiodine ablation, and exhibited, at first rhTSH follow-up, either undetectable Tg (<or=1 ng/mL) (rhTSH1-Tg-, n = 89 patients considered as free of disease) or low Tg (>1-5 ng/mL) (rhTSH1-Tg+, n = 12 patients considered with uncertain prognosis), with no US evidence of residual disease. In all patients, serum Tg measurement after a second rhTSH stimulation and neck US were performed.

RESULTS

At the second follow-up, all 89 rhTSH1-Tg-patients showed a negative US, and Tg became low positive only in one case, whereas it remained undetectable in the other patients. The overall negative predictive value of rhTSH1-Tg- was, then, 98.9%. Out of the remaining 12 patients (i.e., rhTSH1-Tg+ patients), 2 showed disease persistence/recurrence (with a positive predictive value of rhTSH1-Tg+ of 16.7%) and 6 became Tg-.

CONCLUSIONS

A second rhTSH stimulation is useless in DTC patients who were rhTSH-Tg and imaging negative at first follow-up, while it is suggested in patients with detectable, although low, rhTSH-Tg levels at first follow-up: in the absence of clinical or US evidence of disease persistence, these patients should not be retreated by radioiodine, but simply scheduled for a later rhTSH stimulation.

Sonographic imaging of thyroid nodules and cervical lymph nodes

The initial application of sonography for the evaluation of the neck, more than 30 years ago, was to differentiate cystic and solid thyroid nodules. With improvements in technology, ultrasound has been applied to characterize distinct features in the appearance of thyroid nodules. More recently, its function has been expanded to assess cervical lymph nodes for metastatic thyroid cancer. This article discusses the sonographic features of thyroid nodules associated with malignancy and the role of ultrasound in the management of patients with thyroid cancer.

Postsurgical diagnostic evaluation of patients with differentiated thyroid carcinoma: comparison of ultrasound, iodine-131 scintigraphy and PET with fluorine-18 fluorodeoxyglucose

PURPOSE

The aim of this study was to compare the results of ultrasound (US), whole-body scintigraphy with iodine-131 (I-131 WBS) and positron emission tomography with fluorine-18 deoxyglucose (FDG-PET) in the follow-up of patients after thyroidectomy for differentiated thyroid carcinoma (DTC).

MATERIALS AND METHODS

Thirteen patients (3 men, 10 women) were evaluated by neck US, I-131 WBS and FDG-PET. In each patient six anatomical regions (right and left thyroid bed, right and left cervical region, right and left supraclavicular region) were investigated, for a total of 78 regions. Distant metastases were investigated by I-131 WBS and FDG-PET and considered separately in the analysis. Imaging findings were compared with the reference standards, such as fine-needle aspiration cytology (2), biopsy (4) or clinical-radiological studies (7).

RESULTS

US, FDG-PET and I-131 WBS showed concordant negative results in most (70, 90%) of the anatomical sites considered. In one patient with left cervical lymph node metastasis, the imaging techniques showed concordant positive results (1%). In the remaining 7 regions (9%), the imaging results were discordant; in particular, tumour lesions, nodal metastases (4) and thyroid bed recurrences (3) were detected by US only (3), by US and I-131 WBS (1) and by FDG-PET only (3). With regard to distant metastases, FDG-PET and I-131 WBS yielded concordant negative results in the majority (77%) of patients (9); in one patient only were the two imaging techniques concordant in their positive result. In the last three patients, the results were discordant; in particular, distant metastases were detected by I-131 WBS only in two patients and by FDG-PET only in one patient.

CONCLUSIONS

Our work indicates a fundamental role for US in evaluation of the neck after surgery for DTC. WBS is useful to determine differentiation of tumour lesions, to identify thyroid remnants and to look for distant metastases. FDG-PET has an important role in cases of dedifferentiated thyroid carcinoma in which WBS and thyroglobulin measurements are unable to detect tumour lesions.

Imaging for staging and management of thyroid cancer

The management of thyroid cancer has been controversial and, as a result, the routine use of imaging in this disease, especially for pre-operative staging, has lagged behind other head and neck cancers. However, as more is known about the natural history of thyroid cancer, the role of imaging is becoming more established. This review focuses on how imaging now influences the staging and management of the primary cancer, nodal metastases and distant metastases. This is followed by a brief review of the role of imaging in planning post-operative radiotherapy and post-treatment surveillance.

Thyroglobulin measurement in differentiated thyroid carcinoma management

Differentiated thyroid cancer (DTC) is a rare disease with a generally good prognosis. The initial treatment is total thyroidectomy with ablation of thyroid remnants by iodine-131 (¹³¹I). Currently, serum thyroglobulin (Tg) measurement and neck high-resolution ultrasound are the basis of follow-up. The thyroid cells are the only source of Tg in the human body, therefore, the presence of Tg after total thyroidectomy and ablative ¹³¹I therapy indicates persistence or recurrence of DTC. The sensitivity of Tg measurements can be optimized by clinical and technical improvements. Clinically, measurements of thyroid-stimulating hormone (TSH)-stimulated Tg after thyroid hormone withdrawal, or exogenous TSH administration in patients with undetectable serum Tg during thyroid hormone-suppression therapy, is recommended for revealing occult disease. Technically, the development of Tg assays with improved functional sensitivity enhances the value of Tg measurements, allowing us to measure Tg without any TSH stimulation during DTC with high negative predictive value. In particular, increasing serum Tg concentrations in highly sensitive assays are early and reliable indicators of recurrent disease. Several imaging methods are available for the localization of recurrences and metastases (i.e., ¹³¹I whole-body scan for iodine-positive metastases and fluorodeoxyglucose-PET or PET/CT scans for iodine-negative ones), but their rational use should be dictated by Tg testing results. This will be realized in a limited follow-up protocol, warranting the detection of recurrences of DTC and reducing patient burden and medical costs.

Does a highly sensitive thyroglobulin (Tg) assay change the clinical management of low-risk patients with thyroid cancer with Tg on T4 < 1 ng/ml determined by traditional assays?

OBJECTIVE

To evaluate a highly sensitive thyroglobulin (Tg) assay [functional sensitivity (FS): 0.1 ng/ml] (Tg-ICMA) in low-risk patients with known Tg on T4 < or = 1 ng/ml measured by a traditional assay (FS: 1 ng/ml) (Tg-IRMA).

METHODS

Tg-ICMA was measured in serum samples stored at -70 degrees C. Samples were obtained 6 months or more after total thyroidectomy and remnant ablation with (131)I, during L-T4 therapy (TSH < 0.4 mIU/l). All patients had well-differentiated and completely resected tumours, no ectopic uptake on post-therapy whole-body scans and were considered to be at low risk for recurrence. On the occasion of collection and retesting for this study, Tg-IRMA was < or = 1 ng/ml in all samples and no antibody interference was observed.

RESULTS

Tg-ICMA < or = 0.1 ng/ml was observed in 130/178 (73%) patients and recurrence was diagnosed in only 1/130 (0.8%). Tg-IRMA measured after L-T4 withdrawal was > 1 ng/ml in 5/130 (3.8%) patients. Forty-eight (27%) patients had Tg-ICMA > 0.1 ng/ml (0.12-1.6 ng/ml) and recurrence was diagnosed in 5/48 (10.5%). Tg-IRMA measured after L-T4 withdrawal was > 1 ng/ml in 20/48 (41.6%) patients. A negative predictive value of 100% was achieved with Tg-ICMA on T4 < or = 0.1 ng/ml combined with neck ultrasonography (US) or with stimulated Tg-IRMA < or = 1 ng/ml.

CONCLUSIONS

Patients at low risk for recurrence with undetectable Tg on T4 measured by a highly sensitive assay (FS: 0.1 ng/ml) in the absence of antibody interference and with a negative sensitive neck US do not need to be submitted to Tg stimulation. Recurrence is rare in these cases and only a minority of patients convert to stimulated Tg > 1-2 ng/ml.

Limited value of repeat recombinant human thyrotropin (rhTSH)-stimulated thyroglobulin testing in differentiated thyroid carcinoma patients with previous negative rhTSH-stimulated thyroglobulin and undetectable basal serum thyroglobulin levels

CONTEXT

One year after initial treatment, low-risk differentiated thyroid cancer (DTC) patients undergo recombinant human (rh)TSH-stimulated serum thyroglobulin (Tg) (rhTSH-Tg) and neck ultrasound (US).

OBJECTIVE

The need for more rhTSH-Tg in these patients is controversial. We evaluated the utility of a second rhTSH-Tg in DTC patients 2-3 yr after their first evaluation.

RESULTS

At the first rhTSH-Tg, basal and stimulated serum Tg was undetectable in 68 of 85 patients. Neck US was unremarkable in all but one, who had evidence of lymph node disease. Seventeen of 85 patients had undetectable serum Tg that became positive after rhTSH, with negative imaging in 10 and evidence of disease in seven. Patients with no evidence of disease were reevaluated 2-3 yr later (second rhTSH-Tg). In patients in which the first stimulated Tg was undetectable, all had undetectable basal serum Tg, which remained undetectable after rhTSH in 66 of 67 patients (98.5%) and became detectable in one (1.5%) (positive neck US). In the 10 patients with detectable stimulated Tg in the first test, basal serum Tg and US were negative at the second test, but rhTSH-Tg became detectable in six. Compared with the first rhTSH-Tg, the second stimulated Tg in these six patients decreased in one, increased in three, and stabilized in two patients.

CONCLUSIONS

The second rhTSH-Tg was informative in patients who had first stimulated Tg detectable but not in those who had undetectable Tg at the first test, in which the only patient with recurrence was diagnosed by neck US. Thus, rhTSH-Tg should be repeated only in patients who have had a positive first rhTSH-Tg and negative imaging.

Management of low-risk differentiated thyroid cancer

OBJECTIVE

To summarize the definitions of and management recommendations for low-risk thyroid cancer made by the American and European Thyroid Associations and synthesize this information with the recent literature, including systematic evaluations of tumor staging systems guiding therapy.

METHODS

The American Thyroid Association and European Thyroid Association guidelines were compared and pertinent literature since 2005 was reviewed.

RESULTS

Of papillary thyroid microcarcinomas (PTMC), up to 50% breach the thyroid capsule, 64% have lymph node metastases, up to 43% are multifocal, and as many as 2.8% have distant metastases. Locoregional and distant recurrences are, respectively, as high as 5.9% and 1.5%. As many as 1 in 4 patients with a papillary thyroid carcinoma 1.5 cm or smaller develop persistent disease. Cancer-related mortality rates are usually less than 1%, but are as high as 2% in some reports. Tumor staging systems are too inaccurate to guide therapy.

CONCLUSION

It is unlikely that many patients will forgo treatment after understanding their risk, especially when total thyroidectomy and radioiodine (131I) therapy can reduce the PTMC recurrence or persistence disease rate to zero. Preoperatively diagnosed PTMC should be treated with total or near-total thyroidectomy, regardless of tumor size. For very low-risk patients with unifocal PTMC smaller than 1 cm that is removed by chance during surgery to treat benign thyroid disease, lobectomy alone without 131I therapy may be sufficient therapy if there are no concerning histologic features and no tumor extension beyond the thyroid, metastases, history of head and neck irradiation, or positive family history--any of which requires total or near-total thyroidectomy and remnant ablation with 30 mCi.

Preoperative undetectable serum thyroglobulin in differentiated thyroid carcinoma: incidence, causes and management strategy

BACKGROUND

In recent years serum thyroglobulin (Tg) measurement during thyroxine (T4) treatment and/or after stimulation by endogenous TSH or recombinant human TSH (rhTSH) has eclipsed other diagnostic procedures in managing patients with differentiated thyroid cancer (DTC). However, preoperative undetectable Tg was reported in up to 12% of patients affected by DTC and recurrences of DTC with no increase in serum Tg have also been described. Clearly, a negative Tg measurement may falsely reassure both the patient and the clinician in these cases.

AIM

We retrospectively evaluated the incidence of undetectable or reduced preoperative serum Tg in a group of 436 patients affected by DTC. Additionally, we evaluated the role of Tg retesting by two different immunoassays in patients with low Tg at first measurement.

METHODS

We retrospectively selected 17 patients with undetectable (i.e. less than functional sensitivity of assay method) or reduced Tg (i.e. between functional sensitivity and minimum normal value) among 436 patients with histologically proved DTC. The remaining 419 patients were used as control cases. Frozen sera from all patients were retested by two different Tg immunoassays.

RESULTS

Globally, 17 out of 436 (3.8%) patients showed undetectable (n = 5, 1.1%) or reduced (n = 12, 2.7%) preoperative Tg. The Tg level was above the minimum normal value in 3 and 4 out of 5, and 8 and 9 out of 12 of these patients, respectively, when two different immunoassays were employed. On the other hand, undetectable or reduced Tg levels were found in 3.0%-5.1% of control cases when different immunoassays were used.

CONCLUSIONS

Regardless of the method employed, 3.0-5.1% of patients with DTC showed undetectable or reduced preoperative Tg. This fact must be recognized, as Tg cannot be used as a benchmark for DTC follow-up in these cases. However, Tg retesting with different immunoassays seems to be useful in ruling out these pitfalls in a large majority of patients, and also indicates the most effective assay to be employed in these cases.

[Cervical lymph nodes metastases in patients with differentiated thyroid cancer]

Loco-regional recurrences of the differentiated thyroid cancer have been reported to be located in cervical lymph nodes in 60-75% of cases. The widespread use of neck ultrasonography (US) during the follow-up of patients with papillary thyroid carcinoma (PTC) has led to the discovery of small cervical lymph nodes (LN). Although US has a high sensitivity for diagnosing LN, fine needle aspiration biopsy (FNA) and measurement of thyroglobulin in fine needle aspirates (FNA-Tg) have proven to be invaluable tools. The aim of this paper is to review the importance of the early diagnosis of lymph node metastases in the follow-up of patients with differentiated thyroid cancer.

Ultrasound criteria of malignancy for cervical lymph nodes in patients followed up for differentiated thyroid cancer

CONTEXT

Neck ultrasonography (US) has become a keystone in the follow-up of patients with differentiated thyroid cancer.

OBJECTIVE

The aim of this study was to determine specificity and sensitivity of ultrasound criteria of malignancy for cervical lymph nodes (LNs) in patients with differentiated thyroid cancer.

DESIGN

We prospectively studied 19 patients referred to the Institut Gustave Roussy for neck LN dissection. All patients underwent a neck US within 4 d prior to surgery. Only LNs that were unequivocally matched between US and pathology were taken into account for the analysis.

RESULTS

One hundred three LNs were detected on US, 578 LNs were surgically removed, and 56 LNs were analyzed (28 benign and 28 malignant). Sensitivity and specificity were 68 and 75% for the long axis (> or =1 cm), 61 and 96% for the short axis (>5 mm), 46 and 64% for the round shape (long to short axis ratio < 2), 100 and 29% for the loss of fatty hyperechoic hilum, 39 and 18% for hypoechogenicity, 11 and 100% for cystic appearance, 46 and 100% for hyperechoic punctuations, and 86 and 82% for peripheral vascularization.

CONCLUSION

Cystic appearance, hyperechoic punctuations, loss of hilum, and peripheral vascularization can be considered as major ultrasound criteria of LN malignancy. LNs with cystic appearance or hyperechoic punctuations are highly suspicious of malignancy. LNs with a hyperechoic hilum should be considered as benign. Peripheral vascularization has the best sensitivity-specificity compromise. Round shape, hypoechogenicity, and the loss of hilum taken as single criteria are not specific enough to suspect malignancy.

How the availability of recombinant human TSH has changed the management of patients who have thyroid cancer

Recombinant human TSH (rhTSH) is used in patients who have had surgery for thyroid cancer but are at low risk of recurrence. The rhTSH is used for the preparation of postoperative administration of 3.7 GBq (100 mCi) of radioiodine for thyroid-remnant ablation and for the determination of serum thyroglobulin levels during follow-up. In these two conditions, the efficiencies of levothyroxine withdrawal and rhTSH administration are similar; however, rhTSH can be administered during levothyroxine treatment, and its use avoids the hypothyroid period induced by levothyroxine withdrawal, reduces whole body exposure after radioiodine administration, avoids potential morbidity and maintains a better quality of life compared with hormone withdrawal.

Isotretinoin as a diagnostic tool for localization of thyroid tissue in a thyroid cancer patient: a case report

The ability of thyroid cancer to incorporate radioiodine and to produce thyroglobulin (Tg) is an important tool for the diagnosis of tumor relapse. However, some patients show high serum Tg and negative whole body scan (WBS) since some specific thyroid properties may be lost during tumor progression. In these cases, a more careful diagnostic approach is necessary. Here, we report the case of a patient with undetectable serum Tg under levothyroxine (L-T4)-suppressive therapy and with a negative WBS 3 years after apparent thyroid remnant ablation. After detection of Tg mRNA in peripheral blood, the patient was re-investigated, and no suspicious lesions were detected by diagnostic WBS, neck ultrasonography, or thorax computerized tomography, except an elevation of serum Tg during hypothyroidism. Since retinoic acid (RA) is being used for the induction of radioiodine uptake by tumors expressing their receptors, we aimed to reveal the site of thyroid cancer relapse in this patient by isotretinoin administration. We demonstrate that apart from being a therapeutic option in some patients with thyroid cancer, RA can also be able to localize thyroid tissue in patients with high serum Tg and negative WBS.

Links T. A sensitive Tg assay or rhTSH stimulated Tg: what's the best in the long-term follow-up of patients with differentiated thyroid carcinoma?

Sensitivity of thyroglobulin (Tg) measurement in the follow-up of differentiated thyroid carcinoma (DTC) can be optimized by using a sensitive Tg assay and rhTSH stimulation. We evaluated the diagnostic yield of a sensitive Tg assay and rhTSH stimulated Tg in the detection of recurrences in the follow-up of DTC. Additionally the value of imaging techniques for the localization of recurrences was evaluated. We included 121 disease free patients in long-term follow-up for DTC (median 10 years, range 1-34). Tg during thyroid hormone suppression therapy (Tg-on) and rhTSH stimulated Tg were measured with a sensitive Tg assay. Patients with rhTSH stimulated Tg > or =1.0 ng/ml underwent imaging with neck ultrasound, FDG-PET and post therapy 131I WBS. Sensitive Tg measurement resulted in 3 patients with Tg-on > or =1.0 ng/ml, recurrence could be localized in 2 of them. RhTSH stimulation resulted in Tg > or =1.0 ng/ml in another 17 of 118 patients. Recurrence could be localized in only 1 additional patient (1 out of 118 patients). Recurrence was localized by neck ultrasound in 1 of 3, by FDG-PET in 2 of 3 and by post therapy 131I WBS in 2 of 3 patients. In the detection of recurrences in DTC, rhTSH stimulation had very limited additional value in comparison to Tg-on measurement with a sensitive Tg assay. We consider this too low to justify rhTSH stimulation in all patients during long-term follow up. Neck ultrasound, FDG-PET and post therapy 131I WBS showed complementary value in localization of disease, but were only positive in a small fracture of all procedures.

Followup of Patients with Papillary Thyroid Cancer: In Search of the Optimal Algorithm

BACKGROUND

Cervical recurrence occurs in up to 30% of patients after surgical treatment for papillary thyroid cancer. This study sought to determine an appropriate algorithm for followup evaluation.

STUDY DESIGN

Patients undergoing total thyroidectomy for papillary thyroid cancer were identified. Clinicopathologic data were recorded, as were the results of all followup evaluations including radioiodine scan, cervical ultrasonography, and serum thyroglobulin levels. The disease recurrence-free survival probability was estimated, and risk factors for recurrence were determined.

RESULTS

Thyroidectomy with or without neck dissection was performed in 162 patients. We excluded 36 patients (followup less than 6 months in 26, extracervical disease at diagnosis in 4, unknown tumor size in 6) from the analysis. Of the remaining 126 patients, 109 (86.5%) had no evidence of disease, with serum thyroglobulin < 1 ng/mL at last followup; 4 (3.2%) had no evidence of disease (negative imaging), with serum thyroglobulin > 1 ng/mL, and 13 (10.3%) had recurrent disease. Cervical recurrence occurred in nine patients, all detected by routine ultrasonography. Pulmonary metastases occurred in four patients; three were diagnosed by chest CT and one by radioiodine scan. Thyroid stimulating hormone-suppressed thyroglobulin levels were available in 11 of the 13 patients and were elevated in 9. Patients with high T stage (extrathyroidal extension), or high N stage had an increased risk of recurrence.

CONCLUSIONS

A followup strategy emphasizing routine cervical ultrasonography and unstimulated thyroglobulin is effective in identifying patients with recurrent papillary thyroid cancer, and may minimize the indiscriminate use of therapeutic radioiodine for radiographically occult disease. Surgery remains the optimal treatment of cervical recurrence, which is the dominant pattern of treatment failure.

Comparison of seven serum thyroglobulin assays in the follow-up of papillary and follicular thyroid cancer patients

BACKGROUND

Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease.

AIM

The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation.

METHODS

Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9-12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up.

RESULTS

Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19-40% and 68-76% and specificity ranged from 92-97% and 81-91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2-0.3 ng/ml, sensitivity was 54-63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85-87% for Tg1.

CONCLUSION

Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient's reassurance.

Emprego da ultra-sonografia cervical no seguimento de pacientes com carcinoma diferenciado de tireóide

A ultra-sonografia (US) cervical é recomendada na avaliação de todos pacientes com carcinoma de tireóide após a terapia inicial, pois mesmo indivíduos de baixo risco com tireoglobulina (Tg) estimulada indetectável podem apresentar metástases cervicais. Para estas metástases, a US é o método mais sensível, superior à pesquisa de corpo inteiro (PCI) com 131I. Linfonodos cervicais com diâmetro > 5 mm com calcificações finas e/ou degeneração cística quase sempre são de etiologia maligna. Na ausência destas características, o formato arredondado e a ausência do hilo ecogênico são achados "suspeitos", enquanto linfonodos alongados e com hilo ecogênico visível são considerados benignos. A avaliação do fluxo, através do doppler, auxilia no diagnóstico diferencial, usualmente revelando hipervascularização periférica ou mista nos casos malignos. Na presença de linfonodos "suspeitos" na US, a avaliação citológica do material obtido através da punção aspirativa por agulha fina (PAAF) e a dosagem da Tg, obtida do lavado da agulha, são testes úteis e complementares para definir a etiologia, com elevada sensibilidade quando combinados e especificidade de 100%. A US também é útil antes da tiroidectomia, auxiliando e até, em alguns casos, modificando o planejamento cirúrgico; e antes da ablação, para mensuração dos remanescentes tireoidianos e pesquisa de metástases linfonodais persistentes. Outra aplicação desse método de imagem é guiar a injeção de etanol (escleroterapia) ou a introdução de eletrodos para ablação com radiofreqüência em casos selecionados de metástases linfonodais isoladas, como alternativa às terapias convencionais.

Valor diagnóstico da tomografia por emissão de pósitrons / tomografia computadorizada (PET-CT) com flúor-18 fluordeoxiglicose (FDG-18F) em pacientes com carcinoma diferenciado da tireóide, níveis séricos de tireoglobulina elevados e pesquisa de corpo inteiro com iodo negativa

OBJETIVO: Avaliar o papel da PET-CT com FDG-18F na detecção de recidiva e/ou metástase de carcinoma diferenciado da tireóide (CDT) em pacientes com níveis elevados de tireoglobulina (TG) e PCI negativa. PACIENTES E MÉTODO: Os achados da PET-CT de 25 pacientes foram comparados com a avaliação histopatológica e os métodos convencionais de imagem (MC). RESULTADOS: A PET-CT foi positiva em 16 pacientes com resultado verdadeiro-positivo em 14 e falso-positivo em 2 casos (valor preditivo positivo 87,5%). Nove pacientes tiveram PET-CT negativa; dois evoluíram com níveis indetectáveis de TG. Doença residual foi observada na PCI pós-dose terapêutica de uma paciente. Seis pacientes não apresentaram evidências de tumor durante o seguimento (média 16 meses). PET-CT foi concordante com MC em 52%, parcialmente concordante em 12% e discordante (6 falso-negativos e 3 falso-positivos dos MC) em 36%. Foi observada uma tendência de aumento da proporção de PET-CT positiva com o aumento de TG. CONCLUSÃO: A PET-CT com FDG-18F é útil na detecção de recidiva e/ou metástases de CDT com níveis de TG elevados mas PCI negativa. Apresenta alto valor preditivo positivo e é superior aos MC, sendo mais efetiva quanto maior o nível de TG.

Diagnóstico de metástases de carcinoma papilífero de tiróide através da dosagem de tiroglobulina no líquido obtido da lavagem da agulha utilizada na punção aspirativa

Com a introdução da ultra-sonografia cervical (USC) no seguimento dos pacientes com carcinoma papilífero de tiróide (CPT), tornou-se freqüente o encontro de pequenos linfonodos (LNs) cervicais. Porém, apesar de a USC apresentar alta sensibilidade, o estudo citológico obtido por punção aspirativa (PAAF) e, nos últimos anos, a dosagem da tiroglobulina (Tg) no lavado da agulha da PAAF (Tg-PAAF) vêm assumindo papel importante no diagnóstico de LNs cervicais. O objetivo deste estudo é verificar a acurácia da combinação da USC, citologia e Tg-PAAF em LNs suspeitos. Estudamos 32 pacientes que apresentavam 44 LNs à USC, classificados como "inflamatórios" (19) ou "suspeitos" (25). Dos 25 LNs suspeitos, 15 apresentavam Tg-PAAF elevada (13 com citologia compatível com metástases e 2 com citologia não-diagnóstica). Esses 15 LNs (11 pacientes) foram confirmados como metástase de CP pelo exame histopatológico. Os 19 LNs "inflamatórios" e os 10/25 LNs "suspeitos" apresentaram citologia negativa e Tg-PAAF indetectável. Concluímos que a USC apresenta alta sensibilidade na detecção de linfonodos cervicais, porém citologia e dosagem de Tg-PAAF são fundamentais para o diagnóstico. A associação USC, citologia e Tg-PAAF pode ser considerada a abordagem mais sensível e específica na detecção de LNs metastáticos em pacientes com CPT.

Ultrasonographic findings of a newly detected nodule on the thyroid bed in postoperative patients for thyroid carcinoma: correlation with the results of ultrasonography-guided fine-needle aspiration biopsy

We evaluated the ultrasonographic findings and performed ultrasonography-guided fine-needle aspiration biopsy of a newly detected nodule in the thyroid bed of 38 patients with postoperative thyroid carcinoma. Detection of a marginal irregularity, microcalcification, or a shape not parallel to the surrounding tissue plane might allow the identification of recurrent thyroid carcinoma from other benign pathologies mimicking local tumor recurrence.

The role of PET in follow-up of patients treated for differentiated epithelial thyroid cancers

This article provides an update on the use of 2-[(18)F]-fluoro-2-deoxyglucose PET in the follow-up of patients treated for differentiated thyroid carcinoma (DTC). Although DTC recurrence is principally identified by a detectable basal or TSH-stimulated thyroglobulin level, PET helps to localize recurrent disease in patients with normal (131)I total-body scans and other normal anatomic imaging studies. The sensitivity of PET for localization of recurrence ranges from 45% to 100% according to tumor burden and differentiation. Whether PET should be performed after TSH stimulation is unclear, but several studies have reported an increase in the number of lesions detected by uptake of 2-[(18)F]-fluoro-2-deoxyglucose in this setting. Dependent on a center's approach, PET can alter therapeutic management in 9-51% of cases. Furthermore, PET might have a prognostic impact on survival in patients with metastatic disease and aid clinicians in selecting patients who need closer follow-up or aggressive treatment. PET can, therefore, be used advantageously in the follow-up of patients with DTC and can localize disease in patients with elevated thyroglobulin levels, normal total-body scans, and normal findings on conventional imaging modalities. In patients in whom local treatment is planned, especially those with aggressive pathologic variants of thyroid cancer, PET can exclude distant metastases. In patients with metastatic disease, PET can help to identify patients needing closer follow-up.

Radio-guided nonpalpable metastatic lymph node localization in patients with recurrent thyroid cancer

The detection of nonpalpable recurrent thyroid carcinoma has increased due to the use of imaging techniques in time. This report is to investigate whether preoperative injection of a radiotracer under ultrasound guidance is useful in nonpalpable recurrent thyroid carcinoma. The neck of two patients with recurrent thyroid carcinoma was scanned with the probe to localize the area of maximal radioactivity allowing appropriate location of the incision over the lesion. After the lymph nodes were removed, radioactivity was measured in the lesion bed to confirm the success of the dissection. In conclusion, the radio-guided nonpalpable lesion localization technique can be performed safely for the detection and excision of metastatic foci.

Hook needle-guided excision of recurrent differentiated thyroid cancer in previously operated neck compartments: a safe technique for small, nonpalpable recurrent disease

CONTEXT

As a result of more sensitive techniques to detect recurrent thyroid cancer, the number of patients presenting with small, nonpalpable recurrent thyroid cancer in cervical lymph nodes is increasing. Surgical excision of nonpalpable recurrent thyroid cancer can be difficult, particularly in a previously operated area.

OBJECTIVE

The objective of this study was to investigate whether preoperative insertion of a hook needle under ultrasound guidance is useful in neck reoperations for recurrent thyroid cancer.

PATIENTS

Ten consecutive patients presenting over a 4-month period with nonpalpable, ultrasound-visible, fine needle biopsy-proven recurrent thyroid cancer in previously operated neck compartment(s) were studied.

MAIN OUTCOME MEASURES

We measured whether it was technically possible to insert a hook needle preoperatively, rate of negative neck exploration, and complication rate.

RESULTS

The hook needle was inserted in seven patients. In three patients, the hook needle was not inserted; one patient had palpable disease 4 months after the preoperative clinic visit, one patient had a tumor too close to the carotid artery, and one patient had multiple bilateral foci of recurrent disease in the central neck. One patient had bleeding after insertion of the needle due to a penetration of an anterior jugular vein that was easily managed at neck reexploration. No other complication occurred during the hook needle insertion, and the only surgical complication was a transient recurrent nerve palsy. All pathology reports showed malignant disease.

CONCLUSION

Hook needle-guided excision of recurrent thyroid cancer is feasible and appears to be a promising tool for safe and successful reoperation of patients with small recurrent thyroid cancer in cervical lymph nodes.

Re-operative neck surgery for well-differentiated thyroid cancer of follicular origin

This review focuses on the pathologic criteria for completion thyroidectomy in well differentiated thyroid cancer as well the diagnosis and treatment of recurrent disease. The roles of ultrasound in the diagnosis of a cervical recurrence, its value in determining the extent of lymph node dissection in the lateral compartment, and the importance of intra-operative ultrasound in re-operative thyroid surgery are discussed.

[Thyroglobulin mRNA amplification in peripheral blood of patients with differentiated thyroid carcinoma: what does it really mean?]

Despite the excellent prognosis, differentiated thyroid carcinoma (DTC) may recur in 20-40%, and prognosis is particularly related to early detection of recurrent disease. Therefore, long-term follow-up with sensitive tests is need. Serum thyroglobulin (Tg) has an established role as a tumor marker of relapse. However, there are technical limitations of Tg immunoassays, in special, the interference of anti-Tg antibodies and the method sensitivity is dependent on TSH stimulation. Detection of circulating malignant cells by amplification of tumor-specific mRNA showed initial promising results. However, almost one decade of studies of Tg mRNA detection in peripheral blood, its real contribution for DTC follow-up had not yet been established. After a critical analysis of published data, it is clear that there are many protocol differences and conflicting results. Therefore, it seems that amplification of thyroid-specific mRNAs is not superior to sensitive Tg assays and illegitimate transcription and alternative splicing of Tg are factors that may influence mRNA test specificity.

Câncer diferenciado da tiróide de baixo risco: revisão do estado atual da literatura e proposta de conduta

A incidência do câncer diferenciado da tiróide vem aumentando há várias décadas no Brasil, assim como em todo o mundo. A popularização de métodos diagnósticos sensíveis e de uso relativamente simples tem contribuído para o diagnóstico cada vez mais freqüente de carcinomas de pequeno tamanho. Uma parte destes tumores ocorre em pacientes denominados de baixo risco, que poderiam se beneficiar de estratégias de conduta menos agressivas. Entretanto, a definição de baixo risco ainda é confusa e não existem meios seguros para distinguir os pacientes que evoluirão de forma pior dos demais. Por outro lado, o uso de novos métodos de acompanhamento vem mudando a maneira de conduzir estes casos. Um grupo multidisciplinar que inclui pesquisadores básicos, endocrinologistas, médicos nucleares, cirurgiões e patologistas endócrinos reviu a literatura pertinente e, com base em sua experiência, propõe algumas normas de conduta no carcinoma diferenciado da tiróide chamado de baixo risco em nosso meio.

Nodal yield, morbidity, and recurrence after central neck dissection for papillary thyroid carcinoma

BACKGROUND

The role of central neck dissection (CND) in differentiated thyroid cancer remains controversial. This study aims at elucidating the potential benefits and drawbacks of CND associated to total thyroidectomy in papillary cancer.

METHODS

Protocols of patients undergoing total thyroidectomy and CND for papillary cancer were reviewed. The following data were recorded: macroscopic appearance of central nodes; nodes obtained at operation; number of metastatic nodes and parathyroid glands incidentally resected; metastases, age, completeness, invasiveness, size score; postoperative s-Ca; complications; and recurrences. Differences between therapeutic (gross nodal involvement) and prophylactic (no apparent node involvement) CNDs were studied.

RESULTS

Forty-three patients (mean age, 52 +/- 17 years) were studied. A mean of 8.4 +/- 6.6 nodes were resected per patient. A 60% prevalence (26/43) of presence of nodal involvement (N+) was found with no difference between low- and high-risk patients. Twenty-five (60%) patients developed transient hypocalcemia, which was associated with incidental parathyroidectomy, number of nodes resected, and thymectomy. Two patients (4.6%) developed permanent hypoparathyroidism and 3 (7%), transient vocal cord paralysis. Parathyroid glands were found in 19% of the specimens. At follow-up, there were no central neck recurrences, but 5 patients developed lateral recurrences despite treatment with I(131). All 5 patients had had therapeutic CND with 6 or more metastatic nodes obtained in the CND specimen. No lateral neck recurrences were observed after prophylactic CND or in patients with < 6 nodes involved.

CONCLUSIONS

CND prevents central neck recurrences. Morbidity of bilateral CND is significant, and its systematic implementation in the absence on gross nodal involvement requires reassessment.

Papillary thyroid cancer: medical management and follow-up

The incidence of epithelial derived thyroid cancer (papillary thyroid cancer and follicular thyroid cancer, known collectively as differentiated thyroid cancer) is rising. About 80% of patients with thyroid cancer have PTC and are best treated with thyroidectomy and functional lymph node dissection, followed by radioiodine ablation or therapy and performance of a posttreatment whole-body scan, followed by thyroid stimulating hormone (TSH) suppression. One year after radioiodine administration, the use of sensitive thyroglobulin (Tg) assays can separate the vast majority of patients with persistent disease from those who are free of disease and unlikely to have recurrent disease all without the need for repeat whole-body radioiodine imaging. Patients with detectable serum Tg during TSH suppression (Tg-on) or Tg that rises above 2 ng/mL after TSH stimulation (TSH-Tg) are highly likely to harbor residual tumor. TSH stimulation can be achieved using either thyroid hormone withdrawal or recombinant human TSH (rhTSH). Highly skilled screening neck ultrasonography can identify a few additional patients with subcentimeter residual neck lymph node metastases not detected by TSH-Tg. However, ultrasonography and chest computed tomography (CT) are most critical for tumor localization in those patients with Tg values that suggest residual disease or in those patients with persistent antithyroglobulin antibodies (TgAb) that falsely lower Tg measurement. TgAb quantitative titers typically resolve steadily over just a few years in patients free of disease after initial therapy. Another paradigm shift is the recognition that most patients who eventually achieve freedom from disease do so by surgery with fewer patients cured by repetitive radioiodine treatments, and even fewer cured with external beam radiation. Patients who appear to be free of disease require a lifetime of follow-up to optimize levothyroxine treatment, and they will undergo periodic stimulation testing because some will still manifest recurrent disease. Patients with persistent disease despite negative ultrasonography, chest CT, and whole-body radioiodine imaging may have a tumor identified by fluorodeoxyglucose positron emission tomography, optimally performed with combined TSH stimulation and image fusion with CT or magnetic resonance imaging. Patients with metastatic disease who are unresponsive to conventional treatment are encouraged to participate in increasingly available thyroid cancer-specific clinical trials using targeted experimental oral or intravenous chemotherapeutic agents to address this tumor that has historically proven resistant to conventional chemotherapeutic agents.

Detection and surgical treatment of cervical lymph nodes in differentiated thyroid cancer

There is considerable controversy regarding the treatment of patients with cervical metastases from differentiated thyroid cancer. Most have papillary carcinoma and the main areas of contention relate to methods of assessment and staging, surgical management and mode of follow up. there is little evidence to support elective anatomical imaging with CT or MRI in those patients with suspected or proven malignancy at the primary site as indicated by fine needle aspiration cytology (FNAC) but who have no clinical evidence of nodal disease. The role of routine ultrasound (US) in the pre-operative assessment of suspected or known malignancy is developing but is largely unproven. When it is performed, high risk areas for metastatic neck disease (levels II-V) should be assessed. Suspicious nodes on US should be further evaluated by FNAC. Suspected or proven neck disease may be further assessed pre-operatively with CT or MRI and then treated surgically. Disease in the central compartment requires a total thyroidectomy and level VI central compartment neck dissection. Suspected or proven lateral compartment cancer should be treated by selective neck dissection (at least levels III, IV, and V) below the accessory nerve. There is no role for 'Berry picking' and clinically node negative high risk patients should have an elective central compartment level VI neck dissection. Sentinel node biopsy lays no role and neither does elective lateral compartment surgery in patients with no clinical or radiological evidence of disease. For follow up, US represents the most sensitive means of detecting neck recurrences and in the presence of an elevated serum thyroglobulin, imaging may also include whole body iodine-131 scanning and anatomical imaging with CT or MRI. The role of PET remains controversial but is likely to develop further as the technique becomes more widely available. In the future, the concentration of patients with this disease in large center can only improve the way we treat differentiated thyroid cancer.

What the clinician wants to know: surgical perspective and ultrasound for lymph node imaging of the neck

Imaging of lymph node metastases in the neck can have two major indications: (1) prognosis and assisting with choice of treatment; (2) staging and detection of clinically occult metastases in different levels of the neck. Both indications are discussed. The role and limitations of US and US-guided fine-needle aspiration cytology are also reviewed.

Chronic Granulomatous Lesions After Thyroidectomy: Imaging Findings

OBJECTIVE

The purpose of this report is to describe the imaging appearance of granulomatous inflammation in the neck presenting as a late complication in patients who have undergone thyroidectomy for differentiated thyroid carcinoma.

CONCLUSION

Granulomatous inflammation can occur as a palpable mass in the operative bed of asymptomatic patients who have undergone thyroidectomy for thyroid carcinoma. The diagnosis may be suggested when the lesion shows the sonographic appearance of a poorly defined hypoechoic lesion or lesions with a central echogenic nonshadowing focus, often within the sternocleidomastoid muscle. These lesions may appear as complex cystic masses on CT and MRI and may have increased activity on PET. Percutaneous biopsy can establish the diagnosis of an inflammatory lesion and can exclude underlying active infection and malignancy.

Prognostic factors for persistent or recurrent disease of papillary thyroid carcinoma with neck lymph node metastases and/or tumor extension beyond the thyroid capsule at initial diagnosis

CONTEXT

Reliable prognostic factors are needed in papillary thyroid cancer patients to adapt initial therapy and follow-up schemes to the risks of persistent and recurrent disease. OBJECTIVE AND SETTINGS: To evaluate the respective prognostic impact of the extent of lymph node (LN) involvement and tumor extension beyond the thyroid capsule, we studied a group of 148 consecutive papillary thyroid cancer patients with LN metastases and/or extrathyroidal tumor extension. Initial treatment, performed at the Institut Gustave Roussy between 1987 and 1997, included in all patients a total thyroidectomy with central and ipsilateral en bloc neck dissection followed by radioactive iodine ablation.

RESULTS

Uptake outside the thyroid bed, demonstrating persistent disease, was found on the postablation total body scan (TBS) in 22% of the patients. With a mean follow-up of 8 yr, eight patients (7%) with a normal postablation TBS experienced a recurrence. Ten-year disease-specific survival rate was 99% (confidence interval, 97-100%). Significant risk factors for persistent disease included the numbers of LN metastases (>10) and LN metastases with extracapsular extension (ECE-LN >3), tumor size (>4 cm), and LN metastases location (central). Significant risk factors for recurrent disease included the numbers of LN metastases (>10), ECE-LN (>3), and thyroglobulin level measured 6-12 months after initial treatment after T4 withdrawal.

CONCLUSION

We highlight an excellent survival rate and suggest risk classifications of persistent and recurrent disease based on the numbers of LN metastases and ECE-LN, LN metastases location, tumor size, and thyroglobulin level.

Recombinant human thyrotropin is helpful in the follow-up and 131I therapy of patients with thyroid cancer: a report of the results and benefits using recombinant human thyrotropin in clinical routine

There is no doubt that the availability of recombinant human thyrotropin (rhTSH) is one of the milestones in the management of patients with differentiated thyroid cancer (DTC). It offers the opportunity to obtain representative serum thyroglobulin (Tg) levels and diagnostic whole-body scanning (Dx WBS) with 131I under adequate TSH elevation, while the patient continues to receive thyroid hormone. But rhTSH is also used with success in the treatment of local recurrences and distant metastases. In this retrospective analysis we were able to show that our excellent clinical experiences with the use of rhTSH (rare side effects and high compliance) could also be demonstrated by sufficiently elevated TSH levels and representative stimulated Tg measurements. Since April 2001 most of the patients with thyroid cancer in our hospital have undergone diagnostic examination (205 patients underwent 319 examinations) and 131I therapy (a total of 68 treatments) with rhTSH stimulation excluding the first radioiodine ablation of remnants after initial thyroidectomy. Our results show that under rhTSH stimulation 83.5% (diagnostic group) and 88% (therapy group) of our patients with DTC obtained a TSH level of greater than 80 mU/L after two injections of rhTSH (Thyrogen, Genzyme Corp., Cambridge, MA) 0.9 mg intramuscularly 24 hours and 48 hours before the administration of 131I. Only 2.3% (diagnostic group) and 0% (therapy group) demonstrated TSH levels less than 50 mU/L. Serum Tg levels under rhTSH-stimulated conditions showed that in 81.2% the serum Tg maximum was obtained on day 5. Because of the costs associated with periodically rhTSH-assisted Tg testing and based on the data of other studies we are now testing mainly on day 5 to identify residual tumor mass and to compare these Tg levels in the follow-up. Our experience demonstrates that the administration of rhTSH is a safe, effective, and-from an economic point of view- valuable tool in the management of patients with DTC.

Usefulness of fine needle aspiration cytology in the diagnosis of loco-regional recurrence of differentiated thyroid carcinoma

AIM

The aim of our study was to define the usefulness of fine needle aspiration cytology (FNAC) in the assessment of loco-regional recurrence of differentiated thyroid carcinoma (DTC).

METHODS

Among 1182 consecutive patients treated and followed for DTC from 1992 to 2001, we retrospectively analysed 65 FNAC results of patients presenting a suspicion of loco-regional recurrence. Recurrences were proved at histology in 35 cases and by cervical radioiodine uptake on post-therapeutic WBS (whole body scan) in nine cases.

RESULTS

Among the 44 recurrences, FNAC results were malignant, benign and unsatisfactory in 33, two and nine cases, respectively. For the diagnosis of malignancy, FNAC sensitivity was 94%, specificity 100%, positive predictive value 100% and negative predictive value 87%. In the 35 cases where divergent results between diagnostic WBS (37-111MBq (131)I) and Tg level were observed, FNAC assessed the final status in 22 cases (malignant and benign in 17 and five cases, respectively). Of the 12 non-functioning and non-secreting lesions, FNAC diagnosed malignancy in four of the five malignant cases and ruled out malignancy in all seven benign lesions.

CONCLUSION

These results outline the interest of FNAC in the assessment of loco-regional recurrences of DTC, especially when classical follow-up tools such as WBS and/or Tg level are unable to detect the recurrences.

Usefulness of Thyroglobulin Measurement in Fine-needle Aspiration Biopsy Specimens for Diagnosing Cervical Lymph Node Metastasis in Patients with Papillary Thyroid Cancer

The diagnosis of lymph node metastasis in patients with papillary thyroid cancer is an important factor when deciding to perform neck dissection at the initial surgery, as well as for evaluating the lymph node swelling after surgery. Ultrasound (US)-guided fine-needle aspiration biopsy cytology (FNAB-C) is the most useful technique for diagnosing lymph node metastasis. Recently, however, measurement of thyroglobulin in the wash-out of the needle (FNAB-Tg) has been proposed for early detection of neck lymph node metastasis in patients with differentiated thyroid cancer. The purpose of this study was to evaluate the usefulness of FNAB-Tg in detecting lymph node metastasis prior to initial or reoperative thyroid surgery. US-guided FNAB-C was performed on 129 enlarged lymph nodes of 111 patients before surgery. All of them were later histologically confirmed to contain metastasis. Immediately after obtaining an FNAB-C specimen, the needle was rinsed with 0.5 ml of normal saline solution, and the wash-out was subjected to measurement of the Tg level (FNAB-Tg). If the FNAB-Tg level was higher than the serum Tg of the patient, we diagnosed the lymph node as positive (metastatic lymph node). FNAB-Tg sensitivity was 81.4%, and FNAB-C sensitivity was 78.0%. Altogether, 4 (36.4%) of 11 cases judged "benign" and 6 (37.5%) of 16 cases judged "inadequate" by FNAB-C were positive by the FNAB-Tg measurement. Thyroglobulin measurement in fine-needle aspiration biopsy wash-out is thus a useful technique for diagnosing lymph node metastasis of papillary thyroid cancer.

Clinical value of different responses of serum thyroglobulin to recombinant human thyrotropin in the follow-up of patients with differentiated thyroid carcinoma

In the present study we examined the clinical value of a differential response of thyroglobulin (Tg) concentration after recombinant human thyrotropin (rhTSH) stimulation (rhTSH Tg testing) and its correlation with (131)I uptake and whole-body scanning (rhTSH-WBS) in 104 patients who had previously undergone near-total thyroidectomy and (131)I ablation for differentiated thyroid carcinoma (DTC). rhTSH Tg testing was considered negative for rhTSH-Tg less than 0.9 ng/mL, low positive for rhTSH-Tg of 1-5 ng/mL and high positive for rhTSHTg greater than 5 ng/mL. rhTSH Tg testing was negative in 70 patients, 1 of whom had a lymph-node metastasis, but no (131)I uptake. Seven patients had low positive rhTSH Tg testing and no (131)I uptake, but 2 of these patients had cervical lymph node metastases. Twenty-seven patients had high positive rhTSH Tg testing and (131)I uptake was detected in lung, bone, or mediastinum in 11. Imaging techniques (computed tomography [CT], magnetic resonance imaging [MRI], fluorine-18 2-fluoro-2-deoxy-D-glucose-positron emission tomography [FDGPET]) documented metastatic disease in 22. In conclusion, our results suggest that any rise in rhTSH-Tg, even at low level, should raise the suspicion of persistent or recurrent DTC. Patients with rhTSH-Tg at high level should be carefully evaluated, because DTC persistence is highly probable. TSH-WBS provides little adjunctive information.