Análisis de tiroglobulina preablativa y cáncer diferenciado de tiroides preoperatorio / Analysis of pre-ablative and preoperative thyroglobulin in differentiated thyroid cancer

BACKGROUND: The measurement of plasma thyroglobulin (Tg) is widely used in the monitoring of differentiated thyroid cancer (CDT). In recent years, its value as a prognostic marker prior to ablation with radioiodine has increased, demonstrating its high negative predictive value. Recent studies indicate that a wide variety of factors could potentially influence pre-ablative Tg values, including residual tumor burden and stimulation modality. Aim: To relate the value of pre-ablative Tg with the amount of preoperative disease burden, lymph node metastases, treatment, and presence of residual disease. MATERIAL AND METHODS: Retrospective observational study of 70 patients with CDT treated between 2012 and 2018. The amount of disease burden was defined as the sum of largest diameter of individual tumors in each patient, and as the individually largest tumor per patient and number of metastatic lymph nodes. RESULTS: A smaller tumor size and absence of remnant tissue was associated with lower Tg values, although the association was not always significant. Furthermore, no significant difference was found between Tg levels measured within or more than 14 days after the surgical procedure. Thus, an early measurement of pTg after surgery would allow an initial therapeutic decision making. Conclusions: A statistical association between pre-ablative Tg levels and the amount of preoperative tumor tissue burden was found in some subgroups of patients.

Métodos de tiroglobulina de primera y segunda generación: su utilidad en pacientes con cáncer diferenciado de tiroides / First and second generation thyroglobulin measurement methods: Their usefulness in patients with thyroid cancer

El cáncer diferenciado de tiroides (CDT) es el cáncer endocrinológico más frecuente y en las últimas décadas su incidencia ha aumentado. El seguimiento de la enfermedad se efectúa con la medición de tiroglobulina (Tg) sérica, ecografía cervical y barrido corporal total diagnóstico. Los métodos de Tg han evolucionado a través del tiempo. Actualmente, los ensayos inmunométricos de Tg se clasifican en 1.ª y 2.ª generación (1.ª G y 2.ª G). Comprobamos que los ensayos de 2.ª G alcanzan una precisión adecuada para medir valores del orden de 0,1 ng/ml y los de 1.ª G de 1 ng/ml. La bibliografía señala que en el caso de los pacientes de bajo riesgo, una Tg bajo levotiroxina indetectable por un método de 2.ª G puede evitar la realización de Tg estimulada, sea por la suspensión de la terapia hormonal como por el empleo de la TSH recombinante humana, debido a su mayor sensibilidad. Sin embargo, por su menor especificidad, un valor detectable no asegura la presencia de enfermedad, y debería confirmarse. Para optimizar la utilidad clínica de dicha medición se podrían emplear valores de cortes de acuerdo con la población y el método en lugar de la sensibilidad funcional o límite de cuantificación del mismo. Se señalan también otros aspectos críticos en la medición de Tg como son la discordancia entre distintas metodologías y las interferencias en su medición, principalmente por anticuerpos antitiroglobulina. En presencia de interferencias pierden utilidad los ensayos de Tg de 1.ª y 2.ª G. El seguimiento de los pacientes con Tg interferida tiene limitaciones todavía no resueltas. Es importante consensuar entre médicos y bioquímicos las dificultades técnicas y los criterios de interpretación de los valores de Tg en el seguimiento de los pacientes con CDT.

Differentiated thyroid cancer (DTC) is the most common endocrine cancer (tumour) and its incidence has risen in the past decades. Its follow-up includes measuring serum thyroglobulin (Tg), performing neck ultrasound and a diagnostic whole-body scan. Tg assays have evolved with time. At present immunoassays for Tg are classified as 1 st and 2 nd generation assays (1 st G and 2 nd G). 2 nd G assays show an adequate (good) precision at levels close to 0.1 ng/ml and 1 st G assays at levels close to 1 ng/ml. The literature shows that for low risk patients on levothyroxine treatment, who undetectable levels by 2 aG assays can avoid the stimulation test performed by thyroid hormone withdrawal or after recombinant human TSH, due to better sensitivity. However, due to lower specificity, detectable levels do not confirm the presence of disease (tumour), and should be confirmed. To optimise the clinical usefulness of the test, cut-off values specific for population and method should be used, instead of functional sensitivity or quantification limit. Critical issues for measuring Tg are discussed, such as non-harmonisation of methods, and interferences, mainly by antithyroglobulin antibodies (ATg). 1 st and 2 nd G assays are less useful in presence of ATg, and follow up of such patients is limited. Consensus between physicians and the laboratory on technical issues and interpretation criteria of Tg values is of outmost importance in the follow-up of DTC patients.

The Effectiveness of Recombinant Human Thyroid-Stimulating Hormone versus Thyroid Hormone Withdrawal Prior to Radioiodine Remnant Ablation in Thyroid Cancer: A Meta-Analysis of Randomized Controlled Trials

We evaluated the efficacy of recombinant human thyroid-stimulating hormone (rhTSH) versus thyroid hormone withdrawal (THW) prior to radioiodine remnant ablation (RRA) in thyroid cancer. A systematic search of MEDLINE, EMBASE, the Cochrane Library, and SCOPUS was performed. Randomized controlled trials that compared ablation success between rhTSH and THW at 6 to 12 months following RRA were included in this study. Six trials with a total of 1,660 patients were included. When ablation success was defined as a thyroglobulin (Tg) cutoff of 1 ng/mL (risk ratio, 0.99; 95% confidence interval, 0.96-1.03) or a Tg cutoff of 1 ng/mL plus imaging modality (RR 0.97; 0.90-1.05), the results of rhTSH and THW were similar. There were no significant differences when ablation success was defined as a Tg cutoff of 2 ng/mL (RR 1.03; 0.95-1.11) or a Tg cutoff of 2 ng/mL plus imaging modality (RR 1.02; 0.95-1.09). When a negative 131I-whole body scan was used solely as the definition of ablation success, the effects of rhTSH and THW were not significantly different (RR 0.97; 0.93-1.02). Therefore, ablation success rates are comparable when RRA is prepared by either rhTSH or THW.

Thyroglobulin measurements in washout of fine needle aspirates in cervical lymph nodes for detection of papillary thyroid cancer metastases / Determinação da tireoglobulina no lavado da agulha da punção aspirativa de linfonodos cervicais para detecção de metástases do câncer papilar de tireoide

OBJECTIVE: The aim of this study was to evaluate the accuracy of the measurement of thyroglobulin in washout needle aspiration biopsy (FNAB-Tg) to detect papillary thyroid cancer (PTC) metastases. SUBJECTS AND METHODS: Forty-three patients (51.4 ± 14.6 years) with PTC diagnosis and evidence of enlarged cervical lymph nodes (LN) were included. An ultrasound-guided fine-needle aspiration of suspicious LN was performed, for both cytological examination and measurement of FNAB-Tg. RESULTS: The median values of FNAB-Tg in patients with metastatic LN (n = 5) was 3,419 ng/mL (11.1-25,538), while patients without LN metastasis (n = 38) showed levels of 3.7 ng/mL (0.8-7.4). Considering a 10 ng/mL cutoff value for FNAB-Tg, the sensitivity and specificity was 100 percent. There were no differences on the median of FNAB-Tg measurements between those on (TSH 0.07 mUI/mL) or off levothyroxine (TSH 97.4 mUI/mL) therapy (3.3 vs. 3.8 ng/mL, respectively; P = 0.2). CONCLUSION: The results show that evaluation of FNAB-Tg in cervical LN is a valuable diagnostic tool for PTC metastases that can be used independent of the thyroid status.

OBJETIVO: O objetivo deste estudo foi avaliar a acurácia da dosagem de tireoglobulina no lavado da agulha da punção aspirativa (PAAF-Tg) de linfonodos (LN) cervicais para detecção de metástases do câncer papilar de tireoide (CPT). SUJEITOS E MÉTODOS: Foram incluídos 43 pacientes (51,4 ± 14,6 anos) com diagnóstico de CPT e evidência de LN cervicais aumentados. Os LN suspeitos foram submetidos à punção aspiração com agulha fina guiada por ecografia para análise citológica e dosagem de tireoglobulina (PAAF-Tg). RESULTADOS: A mediana dos valores de PAAF-Tg nos LN metastáticos (n = 5) foi 3.419,0 ng/mL (11,1-25.538), enquanto nos LN não metastáticos (n= 38) a mediana foi de 3,7 ng/mL (0,8-7,4). Utilizando-se o nível de 10 ng/mL como ponto de corte, observaram-se sensibilidade e especificidade de 100 por cento. Os níveis de TSH sérico não interferiram na dosagem de PAAF-Tg (3,3 e 3,8 ng/mL nos grupos com TSH supresso (TSH 0,07 mUI/mL) e hipotireoidismo (TSH 97,4 mUI/mL), respectivamente, P = 0,2). CONCLUSÃO: Os resultados demonstram que a dosagem de PAAF-Tg é uma ferramenta importante no diagnóstico de metástases do CPT, podendo ser utilizada independente do "status" tireoidiano.

Utilidad de la detección de tiroglobulina en el aspirado de punción ganglionar cervical en el seguimiento de pacientes con cancer papilar de tiroides / Thyroglobulin levels in needle lymph node cytology for the detection of papillary thyroid cancer recurrence

Background: During the detection ofneck recurrence in patients with Papillary Thyroid Carcinoma (PTC), sometimes it is difficult to distinguish metastatic from inflammatory neck lymph nodes. The measurement of serum thyroglobulin (sTg) under thyroid hormone suppression therapy the presence of serum thyroglobulin antibodies (sAbTg), the diagnostic whole body sean and cytology can give false negative results. Measurement of thyroglobulin in the washout fluid from fine-needle aspiration biopsy (FNAB) of suspicious neck lymph nodes could improve the diagnostic aecuracy Aim: To evaluate the usefulness of detecting Tg in lymph nodes (LTg) suspicious by ultrasonography (US) and compare it to cytology. Patients and Methods: Between the years 2004 and 2007 we prospectively studied 30 patients with PTC and cervical US findings of suspicious recurrence. LTg was assayed in US guided FNAB used for cytology. Results: Sixteen out of 30 patients underwent surgery using as selective criteria an LTg higher than sTg or a positive cytology. Surgery confirmed the presence of metástasis in all 15 patients with positive LTg (8 with positive cytology) and in 1 patient with negative LTg and positive cytology (a case with undifferentiated thyroid cancer). The sensitivity was 93.7 percent for LTg and 56.2 percent for cytology. We identified byLTg 3 of 6 patients with undetectable sTg and positive sAbTg. Conclusions: The presence of LTg showed a higher sensitivity than cytology for the detection of cervical lymph node metástasis. This method is useful even in the presence ofsAbTg.

Q12 cáncer diferenciado de tiroides (CDT): estimulación de la TSH endógena con múltiples dosis de TRH y su tratamiento con 131I: experiencia de 3 años / Differentiated thyroid carcinoma: endogenous TSH stimulation by multiple dosage of TRH and treatment with 131I

La búsqueda un método alternativo a la rh-TSH para estimular el aumento de la TSH sérica previo al tratamiento con 131I en pacientes con CDT operados con reducción del tiempo del hipotiroidismo pre ablativo fue el propósito del trabajo que iniciamos en el año 2001 en el Paraguay utilizando múltiples dosis de TRH para estimular la TSH endógena de los pacientes para luego lograr la ablación del remanente tiroideo con 131I. Se conoce que la inyección de una dosis única de 200µU de TRH por vía EV logra el aumento de la TSH endógena en los pacientes con carcinoma diferenciado de tiroides logrando elevar la TSH entre 30 - 35 mUI/L al final de la primera hora , sin embargo, no se cuentan con datos estadísticos de los efectos de múltiples inyecciones de TRH aplicadas por vía EV o por vía IM en los pacientes operados de tiroides por CDT previamente a la ablación con 131I. Material y Método: Desde el 2001al 2007 doscientos pacientes operados por CDT fueron estudiados por este método en el Centro de Diagnostico y Tratamiento Nuclear (CEDIN), 120 correspondieron a cáncer papilar y 80 a cáncer folicular. Ciento ochenta no presentaron metástasis a distancia y 20 presentaron metástasis en cuello, tórax, pelvis y columna dorsal. Tiroidectomía total se realizó en 120 y lobectomía total e itsmectomía más hemilobectomía del lado contra lateral en 80. Todos fueron tratados con dosis ablativas (100 mCi (3.700 mBq) de 131I excepto aquellos con metástasis que recibieron 150 mCi (5.500 mBq) previa estimulación con TRH por vía EV en dos dosis diarias por dos días con previa suspensión de L-tiroxina por 25 días antes del tratamiento reemplazándola por triyodotironina 25 mcg/día por 15 días tras lo cual también fue suspendida 10 días antes de la estimulación con TRH y el tratamiento con 131I. Dos pacientes con metástasis recibieron otra dosis extra de 150 mCi (5.550 MBq) 6 meses después...

The search of an alternative method to the rh-TSH to stimulate endogenous rising of TSH previous to thyroid ablation with 131I in patients with CDT operated. The purpose of the work began in 2001 in Paraguay using multiple dose of TRH IV (200µU of TRH Threlea® Argentina) to stimulate the own TSH of patients previous to 131I ablation. It is known that the injection of an unique dose of 200µU of TRH IV achieves the increasing of the endogenous TSH in patients with differentiated thyroid carcinoma up to 30 - 35 mUI/L at the end of the first hour, however, there is not statistical data of the effects of multiple injections of TRH applied IV or IM in operated patients of DTC previous to the ablation with 131I. Since 2001-2007, two hundred patients operated for DTC were studied by this method, 120 were papillary cancer and 80 follicular cancer. One hundred eighty did not have distance metastasis and 20 presented metastasis in thorax, pelvis and dorsal spine. Total thyroidectomy was carried out in 120 and total lobectomy with itsmectomy plus hemilobectomy of the other lobe in 80. All were treated with ablative dose of 100 mCi (3.700 mBq) of 131I, except those with metastasis which receive 150 mCi (5.500 mBq) with the previous stimulation with TRH IV with two daily dose for three days with previous suspension of L-tiroxine for 25 days and replaced by triyodotiroxine 25 mcg/d for 15 days with suspension 10 days before the stimulation with TRH and treatment with 131I. Two patients with metastasis received another extra dose of 150 mCi (5.550 MBq) 6 months later. One presented uptake in thyroid bed one year after the ablation received a new ablative dose of 100 mCi (3.700 mBq) of 131I. All the patients were interned and isolated by 48 hours. Twenty feminine patients had later pregnancies in 1-3 years after their ablative dose with healthy products. TSH was measured during the stimulation with TRH in all patients...

Thyroid function and anti-thyroid antibodies in Iranian patients with type 1 diabetes mellitus: influences of age and sex

Type 1 diabetes mellitus is frequently associated with autoimmune thyroid disease [ATD].Genetic susceptibility for autoantibody formation in association with ATD and type 1 diabetes mellitus has been described with varying frequencies, but there is still debate about its prevailing situation in Iran. We have therefore investigated the prevalence of anti-thyroid peroxidase [anti-TPO] and anti thyroglubolin [Anti TG] antibodies in type 1 diabetic patients, and compared the effect of age and sex on the thyroid autoimmunity in patients with type 1 diabetes mellitus in Iran. Ninety one subjects with type 1 diabetes mellitus and one hundred and sixty three unrelated normal controls under the age of thirty years were recruited for the detection of anti-TPO and anti-TG. Radio Immuno Assay and chemiluminescence methods were used for anti-TPO and anti-TG detection respectively. Among 91 type 1 diabetic patients, 36 [39.6%] were positive for anti-TPO and 27[30%] were positive for antiTG. Anti-TPO antibodies were detected only in 6.7% of control group. Comparing with those without thyroid autoimmunity, there was a female preponderance for the type 1 diabetic patients with thyroid autoimmunity [female: male, 28:14 vs. 28:20 respectively]. Among the type 1 diabetic patients those with thyroid autoimmunity, tended to be older [p: 0.04] and to have higher TSH concentration [p: 0.03]. Patients with high anti-TPO levels had longer duration of diabetes [P: 0.02]. The presence of anti-TPO in 39.6% of our type 1 diabetic patients comparing with 8.5% of normal subjects confirmed the strong association of ATD and type 1 diabetes mellitus

Diagnóstico de metástases de carcinoma papilífero de tiróide através da dosagem de tiroglobulina no líquido obtido da lavagem da agulha utilizada na punção aspirativa / Diagnosis of metastases in patients with papillary thyroid cancer by the measurement of thyroglobulin in fine needle aspirate

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.

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 study is to determine the sensitivity of the combined use of neck US, FNA biopsy and FNA-Tg for diagnosis of cervical lymph nodes. We have studied 32 patients with 44 LN detected by US, 19 classified as inflammatory and 25 as suspicious. 15 of those 25 suspicious LN had high FNA-Tg (13 of the 15 had positive cytology and 2 indeterminate). All of these 15 LN (11 patients) were proven to be PTC metastasis by histopathology. All 19 inflammatory LN and those 10/25 suspicious LN, had cytology negative for malignancy and undetectable FNA-Tg. We conclude that fine needle aspiration biopsy and FNA-Tg combined with neck US are essential for detecting positive cervical lymph nodes due to its high sensitivity and specificity and it should be considered the standard for investigating locally recurrent disease in patients with PTC.

Management of low-risk patients with thyroid carcinoma and detectable thyroglobulin on T4 after thyroidectomy and ablation with iodine-131

OBJECTIVE: To evaluate the positive predictive value of detectable Tg during T4 therapy (Tg on T4) in patients with thyroid cancer after total thyroidectomy and remnant ablation, discussing the work-up in this situation and the empirical indication of 131I. PATIENTS AND METHODS: Initially, 234 low-risk patients [tumor < 5cm, completely resected, no extensive extrathyroid invasion (pT4)] submitted to total thyroidectomy and ablation with 131I (3.7­5.5 GBq) who presented no ectopic uptake on RxWBS were studied. Of these, 23 patients with detectable Tg on T4 (> 1ng/ml) during the first year after initial therapy were selected. RESULTS: Metastases were detected by neck US in 7 patients, by chest CT in 2 and by US and CT in 3. Four of five patients with lung metastases upon CT had a positive RxWBS. Eleven patients with negative US and CT received a new 131I dose (without DxWBS), and RxWBS showed ectopic uptake in 3 patients. Among the patients with negative RxWBS, 7 remained free of apparent disease and Tg was declining (5 with undetectable Tg on T4 at the end of the study). One patient presented an increase in Tg and FDG-PET was positive for lymph node and bone metastases. CONCLUSIONS: All patients with Tg on T4 > 5ng/ml presented apparent disease. In these cases, even when US and CT are negative, the administration of a therapeutic dose of 131I (without DxWBS) and FDG-PET are recommended. Among patients with detectable Tg on T4 < 5ng/ml and negative US and CT, only 12 percent presented ectopic uptake on RxWBS. These cases could be followed up by monitoring Tg on T4, and RxWBS and FDG-PET should only be performed if this marker does not decrease after 1­2 years.

OBJETIVO: Avaliar o valor preditivo positivo da Tg detectável durante terapia com T4 (Tg sob T4) em pacientes com câncer de tireóide após tireoidectomia total e ablação dos remanescentes, discutindo o manuseio dessa situação e a indicação empírica de 131I. PACIENTES E MÉTODOS: Inicialmente, foram estudados 234 pacientes de baixo risco [tumor < 5cm, completamente ressecado, sem invasão extratireoideana extensa (pT4)] submetidos à tireoidectomia total e ablação com 131I (3,7­5,5 GBq) que não apresentaram captação ectópica com RxWBS. Desses, foram selecionados 23 pacientes com Tg detectável com T4 (> 1ng/ml) durante o primeiro ano após a terapia inicial. RESULTADOS: Metástases foram detectadas em 7 pacientes pelo US cervical, em 2 pela TC de tórax e em 3 pela US e TC. Quatro de 5 pacientes com metástases pulmonares à TC tiveram um RxWBS positivo; 11 pacientes com US e TC negativos receberam uma nova dose de 131I (sem DxWBS), e a RxWBS mostrou captação ectópica em 3 pacientes. Entre os pacientes com RxWBS negativo, 7 permaneceram livres de doença aparente e a Tg estava em declínio (5 com Tg indetectável sob T4 ao final do estudo). Um paciente apresentou aumento da Tg e o FDG-PET foi positivo para linfonodos e metástases ósseas. CONCLUSÕES: Todos os patients com Tg sob T4 > 5ng/ml apresentaram doença aparente. Nesses casos, mesmo quando a US e a TC são negativos, é recomendada a administração de dose terapêutica de 131I (sem DxWBS) e FDG-PET. Em pacientes com Tg detectável sob T4 < 5ng/ml, mas US e TC negativos, apenas 12 por cento apresentaram captação ectópica com a RxWBS. Estes casos podem ser seguidos pelo monitoramento da Tg sob T4, e RxWBS e FDG-PET devem ser feitos apenas se esse marcador não diminuir.

Usefulness of recombinant human TSH aided radioiodine doses administered in patients with differentiated thyroid carcinoma

The published studies confirming the safety and efficacy of rhTSH for diagnostic purposes have ledto an increased interest in its use for preparation for radioiodine (RI) dose administration in patientswith recurrent or persistent differentiated thyroid carcinoma (DTC). In order to establish the efficacy of RItherapy after rhTSH, we have reviewed 39 rhTSH-aided radioiodine treatment in a series of 28 DTC patients.Patients were divided into two groups: GI (n=17), with previous thyroid bed uptake and undetectable thyroglobulin(Tg) levels under levothyroxine treatment and GII (n=11), with proven metastatic local or distant disease.Median follow-up after the first rhTSH-aided radioiodine treatment was 32 ± 13 months (range 8 to 54 months).Sixteen patients (94%) in GI were rendered disease free and one patient was shown to have persistent disease.In GII, the post therapy whole body scan showed pathological uptakes in all cases: in four patients in lungs, infour in mediastinum and in three in lateral neck. In two patients with mediastinum uptake, Tg levels wereundetectable after rhTSH. In the follow-up, two patients with lateral neck uptake were rendered disease free,four patients died (three due to thyroid cancer) and five out of the remaining patients have persistent disease. Inconclusion, rhTSH aided therapy was helpful to eliminate normal thyroid bed remnants in 16/17 (94%) patients(GI). rhTSH stimulated Tg was undetectable in two patients with mediastinal metastasis. We believe that rhTSHis a good alternative to levothyroxine withdrawal for the treatment of DTC with radioactive iodine, increasing thequality of life in these patients. Caution should be recommended in the follow-up of unselected DTC patientsonly with stimulated Tg levels.

Los estudios publicados que confirman la seguridad yeficacia de la TSH recombinante (rhTSH) llevaron a un incremento en el interés para su uso como adyuvanteterapéutico en el CDT (ablación o tratamiento de enfermedad metastática). Para evaluar la efectividad de laadministración de dosis terapéuticas de RI luego de la administración de rhTSH, realizamos un análisisretrospectivo en 28 pacientes con CDT que recibieron 39 dosis de RI. Los pacientes se dividieron en 2 grupos:GI (n=17) pacientes con captación en el lecho tiroideo y niveles indetectables de tiroglobulina (Tg) bajo tratamientosupresivo con levotiroxina y GII (n=11), pacientes con enfermedad metastática local o a distancia, previamentecomprobada. El seguimiento promedio luego de la primera dosis de RI fue de 32 ± 13 meses (rango 8 a 54meses). Dieciseis pacientes (94%) del GI fueron considerados libres de enfermedad y un paciente presentó unapersistencia local. En el GII, las captaciones patológicas fueron: en 4 pacientes en pulmones; en 4 en mediastinoy en 3 a nivel lateral cervical. Dos pacientes con captaciones mediastinales presentaron niveles indetectablesde Tg. En el seguimiento, dos pacientes con captaciones latero-cervicales se consideraron libres de enfermedad,cuatro pacientes murieron (tres debido al CDT avanzado) y cinco de los restantes tienen enfermedad persistente.En conclusión, la terapia con RI luego de rhTSH fue útil para ablacionar remanentes normales en el GI. Losniveles de Tg estimulados con rhTSH fueron indetectables en dos pacientes con metástasis mediastinales. Eluso de rhTSH parece ser una alternativa válida frente a la suspensión de la terapia hormonal en el tratamientode pacientes con CDT, incrementando la calidad de vida de estos pacientes.

(18F)-Fluoro-deoxi-glicose no acompanhamento de carcinoma diferenciado da tireóide / (18F)-Fluorodeoxyglucose in the follow-up of Differentiated Thyroid Carcinoma

Realizou-se análise prospectiva de 27 pacientes submetidos à tireoidectomia total por carcinoma diferenciado da tireóide e divididos em dois grupos, de acordo com os níveis de tireoglobulina (TG) sérica sob a suspensão de tiroxina (grupo I - TG = 10 ng/mL e grupo II - < 10ng/mL) . Os objetivos do trabalho foram: comparar os achados da tomografia por emissão de pósitrons com (18F)-fluoro-deoxi-glicose (FDG) utilizando-se equipamento híbrido não dedicado, pesquisa de corpo inteiro com (131I)iodo e [99mTc]-sestamibi, tomografia computadorizada do tórax e ultra-som cervical na pesquisa de metástases e avaliar a influência dos níveis de hormônio tireotrófico na distribuição do (18F)-FDG.A prospective study was conducted to evaluate the role of dual-head positron emission tomography with (18F)-fluoro-deoxy-glucose (FDG) in the follow-up of differentiated thyroid carcinoma and to determine the influence of thyroxine replacement in the distribution of FDG. Patients (23 female, 4 male; 17-73 years) were analyzed and classified according to their serum thyroglobulin (TG) levels measured without thyroxine in two groups: 17 patients in group I - TG = 10 ng/mL and 10 patients in group II - < 10ng/mL. Results were compared with whole-body iodine and [99mTc]-sestamibi scan, neck ultrasound and chest computed tomography...

Carcinoma insular de tireóide / Insular carcinoma of the thyroid

O objetivo dessa apresentação é discutir o Carcinoma Insular da Tireóide, uma forma rara de neoplasia com características clínicas e histológicas bastante peculiares. Inicialmente, será apresentado o caso seguido de uma breve discussão clínica. Posteriormente, serão discutidos aspectos histológicos e IHQs e os marcadores de agressividade desse tipo de tumor, seguindo-se uma discussão aberta com outros membros do serviço.

Immunohistochemistry of thyroid carcinoma--an experience with thyroglobulin and calcitonin.

A retrospective immunohistochemical study of 33 cases of primary thyroid carcinomas and 5 cases of metastases to thyroid was carried out. The immunostaining for thyroglobulin and calcitonin was done by peroxidase-anti-peroxidase (PAP) technique. The optimum staining results were obtained by proper standardisation of the staining procedure and reagents. The sections were systematically evaluated for immunostaining intensity and distribution. The observations revealed that thyroglobulin and calcitonin could be useful as sensitive and specific histogenetic markers for follicular and parafollicular cell derived thyroid carcinomas respectively. However, there was no absolute correlation between thyroglobulin positivity and grade of differentiation. The immunostaining could not differentiate follicular adenoma from follicular carcinoma. More extensive study using other markers may be useful for better patient management.

Fatores prognosticos nos adenocarcinomas diferenciados da glandula tireoide / Prognostic factors of differentiated thyroid adenocarcinomas

O cancer da glandula tireoide ainda hoje desperta o interesse de muitos pesquisadores. E uma neoplasia que acarreta aumento da morbimortalidade de seus portadores, bem como nao serem definidos claramente seus fatores prognosticos. Foram estudados 117 pacientes portadores de adenocarcinomas diferenciados da glandula tireoide, submetidos a tireoidectomia total entre 1978 e 1991, na tentativa de se determinar quais seriam os fatores prognosticos mais importantes nestas neoplasias...

Estimation of thyroid microsomal and thyroglobulin antibody

Immunofluorescence procedure was applied to measure thyroid autoantibody for the first time in immunology laboratory, Sadam Medical City Hospital. Antibodies to thyroid microsomal [TM], throglobulin [TG] and second colloid Ag [CA2] were studied. The technique was standardized using blood from 156 patients suffering from various thyroid diseases and 95 normal controls age and sex matched with patients. Immunofluorescence test [IF] was compared with the standard haemagglutination method [HA]. It had been found that IF was more sensitive and much cheaper than HA, as the antigen could be prepared locally in the laboratory, while kit for HA is usually imported from abroad-sources. However, application of HA for those sera which were positive by IF would be more beneficial for the patients

Immunohistochemical staining for thyroglobulin in poorly differentiated carcinoma of the thyroid.

Paraffin sections of 14 specimens of poorly differentiated tumours of the thyroid were stained for thyroglobulin using polyclonal antibodies and a streptavidin-biotin peroxidase staining system. The better differentiated areas showed positive staining, while the poorly differentiated areas gave weakly positive or negative staining. Thyroglobulin staining is useful in attributing a thyroid epithelial cell origin to a tumour, but negative staining does not exclude this.

Clinical evaluation of serum thyroglobulin measurements in the follow-up of patients with differentiated thyroid carcinoma

As concentraçöes séricas de tireoglobulina (Tg), T3, T4 e TSH foram analisadas em 52 pacientes com carcinoma diferenciado de tireóide após tireoidectomia total, enquanto a medicaçäo supressiva por L-tiroxina havia sido suspensa. Mapeamento ósseo, radiografia torácica e mapeamento radioisotópico de corpo inteiro (MRCI) foram igualmente solicitados. Os pacientes foram divididos em três grupos: G1) sem remanescente tissular tireóideo na área cervical (n=12); G2) com remanescente tissular tireóideo cervical mas sem metástases locais ou distantes (n=27); e G3) com a presença de metástases pulmonares, ósseas ou cervicais (n=13). As concentraçöes de Tg séricas foram, respectivamente (média DP): 99 + ou - 5,7 µg/L (G1), 29,9 + ou - 22,9 µg/L (G2) e 564,8 + ou - 833,4 µg/L (G3). Observou-se correlaçäo significativa entre os achados clínicos, a presença de MRCI positivo ou negativo e o nível de Tg sérica. As concentraçöes séricas de Tg revelaram-se mais sensíveis que o MRCI para detecçäo de eventual metástase, apesar de haver certo grau de superposiçäo de valores de Tg sérica entre os pacientes dos grupos 2 e 3. Em outro grupo de pacientes (n=141) com diagnóstico prévio de câncer de tireóide diferenciado, analisou-se a Tg sérica por método imunorradiométrico (IRMA), enquanto os indivíduos se achavam sob a açäo de doses supressivas de L-tiroxina. A Tg sérica mostrou-se näo detectável (<1,0 µg/L) em 94 por cento dos pacientes do grupo 1 (sem remanescente tireóideo) e em 75 por cento dos indivíduos do grupo 2. A Tg sérica variou de <1,0 µg/L até 88 µg/L nos pacientes dos grupos 3 e 4. Concluímos que o método IRMA usando dois anticorpos monoclonais é mais sensível e permite melhor acompanhamento, com mais segurança, do paciente com diagnóstico prévio de câncer de tireóide. Recomenda-se que a verificaçäo da Tg sérica seja realizada com um MRCI em pacientes tireoidectomizados, pelo menos na fase inicial.

N-terminal groups of buffalo thyroglobulin.

N-Terminal analysis of purified buffalo thyroglobulin by the fluorodinitrobenzene method of Sanger yielded about 1.5 moles of DNP-glutamic acid per mole of buffalo thyroglobulin. No water-soluble DNP-amino acid was detectable as N-terminal. The presence of glutamic acid has been confirmed by Edman degradation and characterization of the PTH-amino acid in different solvent systems, and also after regeneration of free amino acid from PTH-amino acid in butanol-acetic acid-water (4:1:5, v/v) system. This is in contrast to the occurrence of aspartic acid or asparagine as N-terminals for several other mammalian thyroglobulins.