Diagnosis of neck recurrences in patients with differentiated thyroid carcinoma

Neck recurrence from thyroid carcinoma: serum thyroglobulin and high-dose total body scan are not reliable criteria for cure after radioiodine treatment

BACKGROUND

Local and regional recurrences occur in up to 20% of patients with papillary and follicular thyroid carcinoma. Diagnostic work-up and treatment modalities are still controversial, because nodal control is difficult to ascertain. We assessed the value of serum thyroglobulin (Tg) determination and of high-dose 131I total body scan (TBS) for ascertaining the absence of disease in patients who had already been treated with radioiodine and who subsequently underwent surgery.

METHODS

Between 1990 and 2000, 105 patients who had been treated with radioiodine for lymph node recurrence with initial 131I uptake were included in a standardized protocol performed after withdrawal of thyroid hormone treatment: on day 1, serum Tg determination and administration of 3.7 GBq 131I; on day 4, 131I TBS; on day 5, surgery; on day 8, 131I TBS.

RESULTS

In 25 patients the serum Tg obtained following thyroid hormone withdrawal was undetectable: for these patients, the 131I TBS showed uptake foci in 21 and pathology disclosed neoplastic foci in 19. In 32 patients the serum Tg ranged from 1 to 10 ng/ml: for these patients, the 131I TBS showed uptake foci in 26 and pathology disclosed neoplastic foci in 28. In 48 patients the serum Tg level was above 10 ng/ml: for these patients, the 131I TBS showed uptake foci in 38 and pathology disclosed neoplastic foci in 46. Thus, no uptake was found preoperatively in 20 patients, among whom pathology disclosed lymph node metastases in 16. However, both tests were negative in only two of the 93 patients in whom pathology disclosed neoplastic foci.

CONCLUSION

Serum Tg levels and 131I TBS cannot be considered as reliable indicators for the absence of disease in patients already treated with 131I. However, when both tests are negative, the risk of persistent disease is minimal.

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 < 0.9 ng/mL, low positive for rhTSH-Tg of 1-5 ng/mL and high positive for rhTSHTg > 5 ng/mL. RhTSH Tg testing was negative in 70 patients, one 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 two 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 (CT, MRI, FDG-PET) 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, since DTC persistence is highly probable. TSH-WBS provides little adjunctive information.

The Role of Positron Emission Tomography/Computed Tomography in the Management of Recurrent Papillary Thyroid Carcinoma

OBJECTIVES/HYPOTHESIS

The aim of the study was to evaluate the role of combined positron emission tomography/computed tomography (PET/CT) fusion imaging in the detection and management of recurrent papillary thyroid cancer.

STUDY DESIGN

A retrospective analysis of 33 patients with suspected recurrent papillary thyroid carcinoma who had undergone PET/CT was performed. PET/CT was compared with standard imaging techniques in each patient to determine whether PET/CT contributed to the therapeutic management plan. Histopathological findings were correlated to PET/CT in patients who underwent surgery.

METHODS

The senior author reviewed the charts of 33 patients with recurrent papillary thyroid carcinoma to determine the impact PET/CT had on management. PET/CT was compared with conventional imaging results. In surgical patients, PET/CT was compared with histopathological findings to determine its sensitivity, specificity, accuracy, positive predictive value, and negative predictive value.

RESULTS

In 67% of the cases (22 of 33), PET/CT supplied additional information that altered or confirmed the management plan. Twenty of 33 patients underwent surgery with 36 sites assessed by histopathological analysis. PET/CT correlated with histopathological findings in 25 of 36 distinct anatomical sites, with an accuracy of 70%. The sensitivity of PET/CT in identifying recurrence was found to be 66%, with a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 27%.

CONCLUSION

Combined PET/CT fusion scanning was most useful in the detection and management of recurrent papillary thyroid cancer in patients who had average thyroglobulin levels greater than 10 ng/mL and when the tumor no longer concentrated radioactive iodine. In 100% of the cases in which PET/CT localized a region suspicious for malignancy, histopathological analysis confirmed the results. When PET/CT is positive, it is a powerful tool for predicting exact locations of recurrent papillary thyroid cancer, thus making it a reliable guide for surgical planning. PET/CT is a supplement to conventional imaging and fine-needle aspiration in the workup of recurrent papillary thyroid cancer. A negative finding on PET/CT is not sufficiently reliable to preclude further investigation and treatment.

Is stimulation of thyroglobulin (Tg) useful in low-risk patients with thyroid carcinoma and undetectable Tg on thyroxin and negative neck ultrasound?

OBJECTIVE

To determine the usefulness of thyroglobulin (Tg) stimulation in low-risk patients with undetectable Tg on T4 and negative neck ultrasound (US) after initial therapy of thyroid carcinoma.

METHODS

We evaluated 122 consecutive patients classified as low risk 6 months to 1 year after total thyroidectomy and remnant ablation. All patients had a normal clinical exam, Tg < or = 1 ng/ml during suppressive therapy (TSH < 0.1 mIU/l), and undetectable antithyroglobulin antibodies.

RESULTS

After T4 withdrawal and elevation of TSH to values > 30 mIU/l, 26 patients (21.3%) converted Tg to levels > 1 ng/ml. Metastases were detected in 10 patients, nine showing stimulated Tg levels > 1 ng/ml. Cervical metastases were observed in 9/10 patients and lung metastases in one patient. Neck US identified all cervical metastases. Seventeen patients with stimulated Tg levels > 1 ng/ml initially showed no apparent disease, with a reduction in Tg being observed upon subsequent measurements, and 13 patients presented undetectable Tg off T4 at the end of the study. Undetectable Tg on T4 showed a high negative predictive value (NPV; 91.8%), which increased to 99.1% when combined with neck US. Stimulated Tg levels < 1 ng/ml presented a 98.9% NPV. A total of 113 patients with undetectable Tg on T4 and negative US had to be exposed to hypothyroidism in order to diagnose one further case of metastases.

CONCLUSION

Undetectable Tg on T4 combined with negative neck US presented a high NPV in low-risk patients and Tg stimulation might be avoided in these patients.

Detection of recurrent papillary thyroid carcinoma by thyroglobulin assessment in the needle washout after fine-needle aspiration of suspicious lymph nodes

To evaluate an efficient method of surveillance of low-risk patients with thyroid cancer, ultrasound was performed on 74 postoperative patients being followed for stage I and II papillary carcinoma. All patients were clinically free of cancer 1-43 years after a total thyroidectomy, and were screened with ultrasound and thyroglobulin (Tg) measurement while taking thyroid hormone suppression. Ultrasound revealed findings suspicious of recurrent disease in the lymph nodes of the neck in 21 patients. An ultrasound-guided fine-needle aspiration (FNA) to obtain material for cytology and Tg analysis was done on these 21 patients, 7 of whom tested positive for Tg in their needle washout. Only 3 of the 7 had detectable Tg in their serum, and only 5 of the 7 had positive cytology. Ultrasound (with FNA-Tg analysis of needle washout of suspicious lymph nodes) is proposed as an effective and efficient method of surveillance in these low-risk patients. Presence of Tg in the needle washout proved to be more sensitive than cytology in diagnosing cancer in the lymph nodes and was not affected by positive anti-Tg antibodies in the serum.

Revisitando a tireoglobulina sérica no seguimento de pacientes com carcinoma diferenciado de tireóide

Este estudo avaliou a tireoglobulina (Tg) sérica dosada em hipotireoidismo em 207 pacientes com carcinoma diferenciado de tireóide tratados com tireoidectomia total e ablação com radioiodo e anticorpos anti-Tg indetectáveis. O estadiamento da doença foi definido pelo exame clínico, Tg estimulada, varredura com radioiodo pré e/ou pós-terapia ablativa e outros métodos de imagem (RX, US, TC e varredura com sestamibi). O intervalo médio desde a terapia inicial foi de 2,3 anos. Dos pacientes, 153 (74%) não apresentavam doença evidente, 34 (16,4%) tinham metástases (Mt) cervicais ou mediastinais e 20 (9,6%) Mt distantes. O valor de 1ng/ml da Tg foi o que melhor discriminou pacientes com e sem doença aparente, com 100% de sensibilidade para Mt distantes, 88,2% para doença em leito tireoidiano ou linfonodos e especificidade de 88,8% para Mt de qualquer natureza, e 74,8% considerando apenas Mt distantes. Dos pacientes com Tg <1ng/ml, 2,8% apresentavam Mt cervicais. Doença cervical ou mediastinal representou 26% dos casos com valores de Tg entre 1 e 5ng/ml. Tg entre 5 e 10ng/ml foi associada a Mt distantes em 14,2% dos casos, os demais apresentavam Mt linfonodais. Mt distantes foram diagnosticadas em 51,3% dos pacientes com Tg >10ng/ml. Sugerimos a necessidade de US cervical mesmo em pacientes com Tg <1ng/ml; que pacientes com Tg <5ng/ml sejam investigados apenas com US cervical e TC de mediastino; e que a terapia empírica fique reservada aos casos com Tg no mínimo >5ng/ml.

Sonography in the diagnosis of cervical recurrence in patients with differentiated thyroid carcinoma

OBJECTIVE

To determine the sensitivity of thyroglobulin (Tg), iodine scanning, and sonography in the diagnosis of cervical recurrence of thyroid cancer.

METHODS

This prospective study assessed 81 patients with cervical metastases or extrathyroid invasion at first appearance who underwent clinical examination, scanning, measurement of Tg after thyroxine withdrawal, and sonography about 8 months after thyroidectomy followed by radioiodine treatment. Only patients without distant metastases and without anti-Tg antibodies were included.

RESULTS

Fifty patients showed persistence of the disease in the cervical region, with only 16% of them having had a suspicion on clinical examination, 33 with Tg levels of 2 ng/mL or greater (66% sensitivity), and 29 with positive scan findings (58% sensitivity). A combination of the 2 methods detected disease in 40 (80%) of 50 patients but failed to show 20% of cases that were identified by sonography and confirmed by fine-needle aspiration. Sonography had sensitivity of 96%. Specificity values for Tg, iodine scanning, and sonography were 80.6%, 90.3%, and 87%, respectively.

CONCLUSIONS

Classic follow-up methods may not detect cervical disease in some patients with differentiated thyroid carcinoma, and sonography is necessary even in patients apparently free of the disease.

Diagnostic value of serum thyroglobulin measurements in the follow-up of differentiated thyroid carcinoma, a structured meta-analysis

OBJECTIVE

To investigate to what extent thyroid remnant ablation and withdrawal from thyroxine are required to achieve sufficient accuracy of serum thyroglobulin (Tg) measurements as an indicator of tumour recurrence in the follow-up of patients with differentiated thyroid carcinoma.

DESIGN AND METHODS

We conducted a meta-analysis of the literature from 1975 to 2003 on serum Tg measurements in the follow-up of differentiated thyroid carcinoma. In a computer-based search, we initially found 915 articles that were finally narrowed down to 120. These 120 papers were subjected to strict in/and exclusion criteria, leaving 46 articles (totalling 9094 patients). Data from these articles were extracted in a structured fashion and were grouped according to initial therapy, TSH status, Tg assay method and definition of a 'gold standard'. Original 2 x 2 tables were pooled by summary receiver operating characteristic curve analysis (sROCa), best estimates of sensitivity and specificity being obtained by the combination of sROCa and Mantel-Haenszel odds ratios.

RESULTS

Despite considerable differences between series in laboratory and clinical methodology, we consistently found higher specificity for Tg measurements after thyroid remnant ablation than after surgery alone. Highest pooled sensitivity 0.961 +/- 0.013 (SE) was found for immunometric assay (IMA) after thyroid remnant ablation and thyroid hormone withdrawal, at a specificity of 0.947 +/- 0.007. Pooled sensitivity decreased significantly if ablated patients were tested while on thyroid hormone (0.778 +/- 0.023, at a specificity of 0.977 +/- 0.005). Significantly decreased pooled specificity was found in patients who did not undergo remnant ablation (sensitivity 0.972 +/- 0.023, at a specificity of 0.759 +/- 0.028). If recombinant human TSH (rhTSH) stimulation was used as a substitute for thyroxine withdrawal, sensitivity remained high (0.925 +/- 0.018) while specificity decreased to 0.880 +/- 0.013. In all analyses, specificity of Tg would decrease when unspecified activity in the thyroid region at scintigraphy was considered benign, whereas sensitivity decreased when such activity was considered malignant.

CONCLUSION

This study confirms that the best accuracy of Tg-guided follow-up in patients treated for differentiated thyroid carcinoma is obtained if treatment includes remnant ablation, and Tg testing is performed while off thyroxine.

[Surgical treatment of recurrent thyroid carcinoma]

Recurrent thyroid tumors are much less frequent but more aggressive than primary tumors. The aim is to find out their characteristics, aggressiveness and the possibility of radical surgical excision as well as the frequency of complications.

METHOD AND MATERIAL

Retrospective study on 69 patients operated for recurrent thyroid tumors.

RESULTS

Recurrent tumors were found in 42 patients with papillary, 11 with follicular (8 with Hurthle), 9 with medullary and 7 with anaplastic thyroid tumors. Relapse in thyroid bed on dominant side had 41 patients (59.4%), relapse on the opposite side we found in 19 patients (27.5%) and relapse in lymph nodes outside of thyroid bed in 37 patients (53.6%). In 33/69 patients, the first procedure was incomplete (reduction in 5, partial resection in 19, hemithyroidectomy in 9). The second procedure was incomplete in 14, near total thyroidectomy in 2, total thyroidectomy in 33 and dissection of lymph nodes in 33, among them in 20 with the operation in thyroid bed. Pre-operative recurrent nerve palsy had 2 patients and transitional recurrent nerve palsy occurred after second procedure in 2 patients. Among 33 patients after thyroidectomy for recurrent tumor, postoperative hypoparathyroidism occurred in 8 (24.2%), of whom in 2 permanent (6%). In the group of 54 patients with recurrent differentiated thyroid cancer, radioiodine therapy after first operation had received only 7 patients (13%).

CONCLUSION

The main causes of thyroid cancer relapse are incomplete first procedure and aggressiveness of cancer. It is not always possible to excise the complete recurrent tumor. After surgery for papillary cancer, radioiodine therapy is seldom used.

Valor da varredura com radioiodo em pacientes com carcinoma diferenciado de tireóide de moderado / alto risco com tireoglobulina (sem tiroxina) indetectável após o tratamento inicial

Avaliamos 92 pacientes sem anticorpos anti-tireoglobulina (TgAb) com nível de tireoglobulina (Tg) após suspensão de levotiroxina, indetectável (<1ng/ml) 6 a 12 meses após a terapia inicial, e que foram considerados de moderado / alto risco para recorrência pelos critérios: idade >45 anos; tumor maior que 1,5cm; metástases para linfonodos em 43 (46,7%), invasão extratireoideana local em 26 (28,2%) ou metástases distantes em 23 (25%). A varredura de controle foi negativa em 78,2% dos casos e apresentava captação apenas cervical nos demais. Os casos com captação em leito tireoideano, sem recorrência tumoral evidente, não receberam radioiodo e, após 1 ano, a Tg permaneceu indetectável em todos. Em 4/13 não houve captação na nova varredura. Em oposição, mesmo na ausência de captação e com níveis indetectáveis de Tg, 7 pacientes com recorrência diagnosticada pelo ultra-som (US) foram tratados cirurgicamente. US apresentou sensibilidade de 92,8% para doença loco-regional. Este estudo sugere que, mesmo pacientes de moderado / alto risco com TgAb e Tg (sem T4) indetectáveis após a terapia inicial, não requerem varredura com radioiodo e os mesmos podem ser avaliados por US cervical.

Challenges In Neck Ultrasonography: Lymphadenopathy And Parathyroid Glands

OBJECTIVE

To assess the performance of neck ultrasonography (US) in the detection of lymph node lesions metastatic from differentiated thyroid carcinoma (DTC) and the detection of parathyroid adenomas.

METHODS

Neck US was performed in 667 patients with DTC (173 men and 494 women; mean age, 47.7 years). In cases of suspicious neck nodes, US-guided fine-needle aspiration biopsy (US-FNAB) plus measurement of thyroglobulin in the needle washouts (FNAB-Tg) was done. In addition, 75 patients with primary hyperparathyroidism (pHPT) (15 men and 60 women; mean age, 56 years) underwent neck US and sestamibi scintiscanning for localization of parathyroid adenoma. For confirmation of US findings, US-FNAB plus measurement of parathyroid hormone in the needle washouts (FNAB-PTH) was performed. FNAB-PTH was also measured in 129 suspected parathyroid adenomas incidentally detected in a series of 4,129 patients undergoing neck US examination for thyroid disease.

RESULTS

The presence of DTC metastatic lesions was confirmed in 46 of 95 patients with suspicious neck nodes. US sensitivity and specificity were 82.1% and 91.2%, respectively. The positive predictive value (PPV) of US-FNAB + FNAB-Tg was 94.7%. In the 75 patients with pHPT, US followed by US-FNAB + FNAB-PTH showed a higher PPV (97.5%) in comparison with sestamibi scintiscanning (83.7%) in the detection of parathyroid adenoma. A parathyroid adenoma was also incidentally detected in 0.62% of the 4,129 patients undergoing neck US for thyroid disease.

CONCLUSION

US accurately detects DTC neck metastatic lesions and localizes parathyroid adenomas. Moreover, neck US may lead to discovery of parathyroid incidentalomas.

Parapharyngeal metastases from thyroid cancer

AIM

To emphasise the pattern of lymphatic dissemination in the parapharyngeal space from thyroid cancer.

PATIENTS AND METHOD

Among 696 patients treated for thyroid cancer between 1986 and 2001, parapharyngeal metastasis was diagnosed in three patients, previously treated for papillary thyroid carcinoma.

RESULTS

All three patients have been treated by surgical resection through lateral cervical approach. Two of them were controlled regionally whereas the remaining one had a submucosal pharyngeal metastasis locally resected 27 months after parapharyngeal resection.

CONCLUSIONS

Parapharyngeal metastasis is rare, but should be a recognized pattern of lymphatic dissemination from thyroid carcinoma to avoid unnecessary radioiodine and because surgical resection is efficacious with acceptable morbidity.

Role of preoperative ultrasonography in the surgical management of patients with thyroid cancer

BACKGROUND

Cervical recurrence occurs in up to 30% of patients with differentiated thyroid carcinoma. We retrospectively compared preoperative transcutaneous ultrasonography and physical examination (PE) results in the detection of local-regional metastases (lymph node and soft tissue) in patients with thyroid cancer.

METHODS

Data were collected retrospectively from the medical records of patients with thyroid carcinoma who underwent preoperative ultrasonography. Patients were divided into 3 groups: group 1, those undergoing primary thyroid/neck surgery; group 2, those undergoing reoperation for persistent disease; and group 3, those undergoing reoperation for recurrent thyroid carcinoma. For each group, we recorded the frequencies with which ultrasonography detected disease in a neck compartment (central or lateral) that was normal on PE.

RESULTS

Two hundred twelve patients underwent operation for primary, persistent, or recurrent papillary (n=130), medullary (n=61), or follicular/Hürthle cell (n=21) carcinoma. Ultrasonography detected additional sites of metastatic disease not appreciated on PE in 21 (20%) of 107 group 1 patients, 9 (32%) of 28 group 2 patients, and 52 (68%) of 77 group 3 patients. The surgical procedure performed was altered by the information obtained from preoperative ultrasonography in 82 (39%) of the 212 patients. Of the 107 group 1 patients, cervical recurrence has been detected in only 6 (6%) at a median follow-up of 36 months, in spite of 67 (63%) having tumors larger than 2 cm or lymph node metastases.

CONCLUSIONS

Preoperative high-quality ultrasonography detected lymph node or soft-tissue metastases in neck compartments believed to be uninvolved by PE in 39% of patients. Ultrasound findings altered the operative procedure in these patients, facilitating complete resection of disease and potentially minimizing local-regional recurrence.

Implications of mediastinal uptake of131I with regard to surgery in patients with differentiated thyroid carcinoma

BACKGROUND

Findings of mediastinal uptake of 131I after surgical treatment for differentiated thyroid carcinoma (DTC) are common, especially in young patients. Given the frequency of false-positive findings, a protocol for diagnostic and therapeutic strategies would be useful. With the goal of accurately selecting management strategies, the authors analyzed their data and data found elsewhere in the literature for correlations with the incidence of mediastinal 131I uptake and with treatment for patients exhibiting such 131I uptake.

METHODS

All patients with DTC who were treated between 1978 and 2000 at Groningen University Hospital (Groningen, The Netherlands) and who received adjuvant 131I ablation therapy were included in the current analysis, which involved retrospective review of all relevant data.

RESULTS

Five hundred four patients with DTC initially underwent total thyroidectomy, with additional 131I ablation performed for 489 of these patients. In 48 of 489 patients (9.8%), 131I uptake was seen in the mediastinum on a posttreatment scan. Analysis of those 48 patients and of cases in the literature demonstrated that serum thyroglobulin levels, risk status, and the presence of thymus on radiologic images were important in the surgical decision-making process.

CONCLUSIONS

Mediastinal uptake of 131I on posttreatment scans was found in approximately 10% of patients after total thyroidectomy for DTC. Based on the current data and the data presented in the literature, the authors developed a flow chart for determining appropriate treatment strategies, which included mediastinal dissection for high-risk patients and for patients with serum thyroglobulin levels > 10 ng/mL.