Ultrasonographic differentiation of cervical lymph nodes in patients with papillary thyroid carcinoma after thyroidectomy and radioiodine ablation: a prospective study.

OBJECTIVE: The objective of the present study was to validate an ultrasound (US) classification of cervical lymph nodes (LNs) in patients with papillary thyroid cancer (PTC) after thyroidectomy and radioactive iodine (131I) ablation. METHODS: We performed a prospective study in which the patients were submitted to thyroidectomy and 131I ablation and then followed until neck US revealed LN(s) ≥5 mm. A total of 288 LNs from 112 patients with PTC were evaluated. Patient management was based on LN characteristics grouped according to the classification system studied here. RESULTS: The presence of microcalcifications and/or cystic degeneration of cervical LNs were highly suggestive of a metastatic etiology (specificity of 99.4%). In contrast, the most sensitive finding for LNs affected by PTC was the absence of an echogenic hilum (sensitivity of 100%). In the absence of these findings (microcalcifications, cystic degeneration, echogenic hilum), a metastatic etiology was the most likely in the case of a round LN (specificity of 89%). The differentiation of a spindle-shaped LN without a visible hilum by Doppler analysis permitted us to dichotomize an initial probability of metastases of 13% in 25% (with peripheral vascularization) versus 3.3% (without peripheral vascularization). CONCLUSIONS: Our results confirm that the classification proposed for cervical LNs in patients with PTC is valid for determining patient management following initial therapy.

Elevated plasma factor VIII and von Willebrand factor in women with type 2 diabetes: inflammatory reaction, endothelial perturbation or else?

The association between type 2 diabetes and cardiovascular disease is long recognized. Although perturbations of haemostatic markers have been shown to be associated with macrovascular disease in patients with type 2 diabetes, it is unclear whether these are primarily due to endothelial dysfunction or a result of inflammation. The present study was undertaken to elucidate whether elevated levels of factor VIII (FVIII) and von Willebrand factor (vWF) in women with type 2 diabetes represent endothelial dysfunction, inflammation or an alternate mechanism. Sixty-four women with type 2 diabetes were evaluated using ultrasonography Doppler for carotid intima-media thickness (IMT) and were classified as group A--having no (<1  mm), group B - mild (≥1  mm and no plaque) and group C--moderate (≥1 mm and presence of plaque and stenosis) macrovascular disease. Several haemostatic markers including, FVIII, vWF and fibrinogen were assessed. In addition, thrombomodulin, a marker for endothelial damage, and high-sensitivity C-reactive protein (hsCRP), an inflammatory marker, were also measured. A significant association of elevated FVIII was found in group B and C patients (i.e. patients with IMT ≥1 mm and with plaque). Elevated fibrinogen and vWF levels were also found but confined to group C patients. No significant difference among subgroups was found for any other variable evaluated (hsCRP, thrombomodulin and FVII). In conclusion, plasma FVIII levels are elevated in women with type 2 diabetes and macrovascular disease. It also appears that this is not mediated by inflammation or endothelial injury and is likely to be due to an alternate mechanism.

Frequência do polimorfismo da glicoproteína IIIa de plaquetas (PlA2) em mulheres com diabetes mellitus tipo 2 / Platelet glycoprotein IIIa polymorphism (PlA2) frequency in Type 2 diabetic women

O polimorfismo da glicoproteína IIIa de plaquetas está associado a um aumento no risco de doenças arteriais coronarianas. Mulheres com diabetes mellitus tipo 2 apresentam um aumento de cinco vezes no risco para doenças arteriais coronarianas quando comparadas com mulheres não-diabéticas. O objetivo do presente estudo foi verificar a frequência do polimorfismo da glicoproteína IIIa (PlA2) em mulheres com diabetes mellitus tipo 2 e comparar com a frequência descrita na literatura. A análise do polimorfismo PlA2 foi realizada para 62 mulheres com diabetes mellitus tipo 2 através da reação em cadeia da polimerase seguida de análise do polimorfismo de tamanho de fragmento de restrição (PCR-RFLP). As frequências observadas foram 81 por cento para PlA1A1, 18 por cento para PlA1A2 e 1 por cento para PlA2A2. Não houve diferença significativa entre as frequências observadas e as frequências descritas na literatura. Nossos resultados sugerem que a frequência do polimorfismo PlA2 em mulheres com diabetes mellitus tipo 2 é a mesma observada na população em geral.

The platelet glycoprotein IIIa polymorphism is associated to an increased risk of coronary heart disease. Type 2 diabetic women present a fivefold higher risk of coronary heart disease compared to non-diabetic women. The aim of this study was to verify the frequency of the glycoprotein IIIa polymorphism (PlA2) in type 2 diabetic women and compare this result with the frequency reported for the general population. The PlA polymorphisms of 62 type 2 diabetic women were determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The resulting frequencies were 81 percent for PlA1A1, 18 percent for PlA1A2 and 1 percent for PlA2A2. There was no significant difference between observed frequencies and the frequencies described in the literature. Our results suggest that the frequency of the glycoprotein IIIa polymorphism, PlA2, in type 2 diabetic women is similar to that observed in general population

Is adjuvant therapy useful in patients with papillary carcinoma smaller than 2 cm?

To evaluate tumor recurrence after total thyroidectomy in patients with single papillary carcinoma with size 0.5 mIU/L in >or=50% of the measurements in all patients. Complete remission (stimulated thyroglobulin (Tg) 0.05). Six patients who still had stimulated Tg > 1 ng/mL (<5 ng/mL) showed a >50% decrease in comparison with Tg measured 12-24 months earlier. In conclusion, we suggest a more conservative approach with respect to central-compartment neck dissection, postoperative (131)I, and suppressive therapy in patients with small tumors restricted to the thyroid.

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 (3.7-5.5 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

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.

[Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy]. / Seguimento de pacientes de alto risco com carcinoma diferenciado de tireóide sem doença persistente após a terapia inicial.

This study evaluated the follow-up of high-risk patients with thyroid cancer after initial therapy. A total of 125 high-risk patients (tumor >4 cm and/or extrathyroid invasion and/or lymph node metastases, and age >45 years), with complete resection of the tumor, were selected. All patients underwent total thyroidectomy and ablation with (131)I[3.7-5.5 GBq (100-150 mCi)]. Eighteen patients (14.8%) presenting metastases on post-dose whole-body scan (RxWBS) were excluded. The negative predictive value of stimulated Tg < or =1 ng/ml in combination with neck US during first assessment (612 mo. after ablative therapy) was 96.2% for the absence of recurrence up to 5 years. This value increased to 98.7% when adding WBS performed with 185 MBq (5 mCi) (131)I (DxWBS). The positive predictive value (PPV) of stimulated Tg >1 ng/ml was 52% for the detection of the presence of metastases up to 5 years; however, considering only patients with initially negative DxWBS and US, the PPV was 19% (9% if Tg of 110 ng/ml vs. 40% if Tg >10 ng/ml). Tg levels decreased spontaneously in patients with stimulated Tg >1 ng/ml during first assessment, negative US and DxWBS, and no recurrence during follow-up, with Tg being undetectable in half these patients at the end of 5 years. Twenty patients presented uptake in the thyroid bed upon DxWBS during the first year after ablative therapy, with stimulated Tg and US being negative, and were not treated with 131I; these patients did not relapse and no uptake on DxWBS was observed in 60% after 5 years. Recurrence after 5 years was only 1.3% in patients without apparent disease (negative US and DxWBS) and stimulated Tg <1 ng/ml. An algorithm for the follow-up of high-risk patients after initial therapy is presented in this study.

Malformations in the offspring of women with thyroid cancer treated with radioiodine for the ablation of thyroid remnants.

RATIONALE: Since ovarian function is only temporarily compromised by radioiodine therapy, many women with thyroid cancer treated with radioiodine can become pregnant. The present study evaluated the evolution of these pregnancies and the consequences for the offspring. PATIENTS AND METHODS: We retrospectively analyzed 78 pregnancies of 66 women submitted to total thyroidectomy, followed by radioiodine therapy 3.75-5.5 GBq (131)I, mean 4.64 GBq). In all patients, conception occurred one year after ablative therapy (mean of 30 months). Age ranged form 19 to 36 years (mean of 30.6 years) at the time of radioiodine treatment and from 23 to 39 years (mean of 32.8 years) at the time of conception. RESULTS: Four (5.1%) of the 78 pregnancies resulted in spontaneous abortions. Three (4%) of the 74 deliveries were preterm and there was no case of stillbirth. The birthweight was > 2500 g in 94.6% of the children (+/- SD: 3350 +/- 450 g) and only one infant (1.3%) presented an apparent malformation at birth (intraventricular communication). No difference in the age at the time of radioiodine therapy or conception or in radioiodine dose was observed between pregnancies with an unfavorable outcome and those with a favorable outcome. CONCLUSION: We conclude that pregnancies that occur 12 months after ablative therapy are safe.

Positive predictive value of detectable stimulated tg during the first year after therapy of thyroid cancer and the value of comparison with Tg-ablation and Tg measured after 24 months.

This study evaluated the positive predictive value (PPV) of detectable stimulated thyroglobulin during the first year after treatment of thyroid carcinoma (Tg-1) and the value of comparison with Tg-ablation and measured after 24 months (Tg-2). Forty-two consecutive patients undergoing total thyroidectomy and ablation with detectable Tg-1 (>1ng/mL) were selected. The patients had well-differentiated tumors, which were completely resected, and there was no ectopic uptake on whole body scan after 3.7-5.5GBq I(131). Imaging methods during follow-up revealed metastases in 10 patients (24%) (15% if Tg-1 10 ng=mL). Tg-ablation (cutoff of 10 ng/mL) presented a negative predictive value (NPV) of 91% and PPV of 42%. Comparing Tg-ablation with Tg-1, the PPV of an increase was 100%, whereas the NPV of a decrease was 88%. Thirty-six patients presented negative imaging results upon first assessment and Tg-1 was compared to Tg-2. Metastases were detected in all patients who presented an increase in Tg (n=4), whereas patients without variation (n=4) or with a decrease (n=28) showed no apparent disease. Among disease-free patients (n=32), 50% presented undetectable Tg and 40% showed a >50% decrease after 2 years. In conclusion, most patients with detectable stimulated Tg during the first year after therapy had no metastases, and evaluation of the slope of Tg helped discriminate cases with apparent disease.

Seguimento de pacientes de alto risco com carcinoma diferenciado de tireóide sem doença persistente após a terapia inicial / Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy / Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy

Este estudo avaliou o seguimento de pacientes com câncer de tireóide de alto risco, após a terapia inicial. Foram selecionados 125 pacientes de alto risco (tumor >4 cm e/ou invasão extra-tireoidiana e/ou metástases linfonodais e idade >45 anos), com ressecção tumoral completa. Todos foram tratados com tireoidectomia total e ablação com 131I [3,7­5,5 GBq (100­150 mCi)] e foram excluídos 18 casos (14,8 por cento) com metástases na PCI pós-dose (t-PCI). O valor preditivo negativo da Tg estimulada <1 ng/ml combinada ao US cervical na primeira avaliação (6­12 meses após a terapia ablativa) foi de 96,2 por cento para ausência de recidivas em até 5 anos. Este valor aumentou para 98,7 por cento quando acrescentamos a PCI com 185 MBq (5 mCi) 131I (d-PCI). O valor preditivo positivo (VPP) da Tg estimulada >1 ng/ml foi de 52 por cento para presença de metástases detectadas até 5 anos depois, mas considerando apenas pacientes que apresentaram d-PCI e US negativos inicialmente, o VPP foi 19 por cento (9 por cento se Tg 1­10 ng/ml vs. 40 por cento se Tg >10 ng/ml). Tg reduziu espontaneamente nos pacientes com Tg estimulada >1 ng/ml na primeira avaliação, US e d-PCI negativos e sem recidiva no seguimento, sendo indetectável em metade destes ao final de 5 anos. No primeiro ano após a terapia ablativa, 20 pacientes tiveram captação em leito tireoidiano na d-PCI com Tg estimulada e US negativos e não foram tratados com 131I; estes evoluíram sem recidiva e 60 por cento apresentavam uma d-PCI sem nenhuma captação após 5 anos. Em pacientes sem doença aparente (no US e d-PCI) e Tg estimulada <1 ng/ml, a recidiva em 5 anos foi de apenas 1,3 por cento. Um algoritmo para o seguimento de pacientes de alto risco após a terapia inicial é apresentado por este estudo.

This study evaluated the follow-up of high-risk patients with thyroid cancer after initial therapy. A total of 125 high-risk patients (tumor >4 cm and/or extrathyroid invasion and/or lymph node metastases, and age >45 years), with complete resection of the tumor, were selected. All patients underwent total thyroidectomy and ablation with 131I [3.7­5.5 GBq (100-150 mCi)]. Eighteen patients (14.8 percent) presenting metastases on post-dose whole-body scan (RxWBS) were excluded. The negative predictive value of stimulated Tg <1 ng/ml in combination with neck US during first assessment (6­12 mo. after ablative therapy) was 96.2 percent for the absence of recurrence up to 5 years. This value increased to 98.7 percent when adding WBS performed with 185 MBq (5 mCi) 131I (DxWBS). The positive predictive value (PPV) of stimulated Tg >1 ng/ml was 52 percent for the detection of the presence of metastases up to 5 years; however, considering only patients with initially negative DxWBS and US, the PPV was 19 percent (9 percent if Tg of 1­10 ng/ml vs. 40 percent if Tg >10 ng/ml). Tg levels decreased spontaneously in patients with stimulated Tg >1 ng/ml during first assessment, negative US and DxWBS, and no recurrence during follow-up, with Tg being undetectable in half these patients at the end of 5 years. Twenty patients presented uptake in the thyroid bed upon DxWBS during the first year after ablative therapy, with stimulated Tg and US being negative, and were not treated with 131I; these patients did not relapse and no uptake on DxWBS was observed in 60 percent after 5 years. Recurrence after 5 years was only 1.3 percent in patients without apparent disease (negative US and DxWBS) and stimulated Tg <1 ng/ml. An algorithm for the follow-up of high-risk patients after initial therapy is presented in this study.

Malformations in the offspring of women with thyroid cancer treated with radioiodine for the ablation of thyroid remnants / Malformações na prole de mulheres com câncer de tireóide tratadas com radioiodo para ablação de remanescentes tireoideanos

RATIONALE: Since ovarian function is only temporarily compromised by radioiodine therapy, many women with thyroid cancer treated with radioiodine can become pregnant. The present study evaluated the evolution of these pregnancies and the consequences for the offspring. PATIENTS AND METHODS: We retrospectively analyzed 78 pregnancies of 66 women submitted to total thyroidectomy, followed by radioiodine therapy (3.7­5.5 GBq 131I, mean 4.64 GBq). In all patients, conception occurred one year after ablative therapy (mean of 30 months). Age ranged form 19 to 36 years (mean of 30.6 years) at the time of radioiodine treatment and from 23 to 39 years (mean of 32.8 years) at the time of conception. RESULTS: Four (5.1 percent) of the 78 pregnancies resulted in spontaneous abortions. Three (4 percent) of the 74 deliveries were preterm and there was no case of stillbirth. The birthweight was > 2500 g in 94.6 percent of the children (mean ± SD: 3350 ± 450 g) and only one infant (1.3 percent) presented an apparent malformation at birth (intraventricular communication). No difference in the age at the time of radioiodine therapy or conception or in radioiodine dose was observed between pregnancies with an unfavorable outcome and those with a favorable outcome. CONCLUSION: We conclude that pregnancies that occur 12 months after ablative therapy are safe.

ARRAZOADO: Uma vez que a função ovariana está apenas temporariamente comprometida pela terapia com radioiodo, muitas mulheres com câncer de tireóide tratadas com radioiodo podem engravidar. O presente estudo avaliou a evolução dessas gravidezes e suas conseqüências para a prole. PACIENTES E MÉTODOS: Analisamos retrospectivamente 78 gravidezes de 66 mulheres submetidas a tiroidectomia total seguida de radioiodoterapia (3,7­5,5 GBq 131I, média 4,64 GBq). Em todas, a concepção ocorreu um ano após a terapia ablativa (média de 30 meses). A idade variou de 19 a 36 anos (media de 30,6) à época do tratamento com radioiodo e de 23 a 39 anos (média de 32,8) na época da concepção. RESULTADOS: Quatro (5,1 por cento) das 78 gravidezes resultaram em abortamento espontâneo. Três (4 por cento) dos 74 partos foram pré-termo, mas não houve nenhum natimorto. O peso ao nascer foi >2.500 g em 94,6 por cento das crianças (média ± DP: 3.350 ± 450 g) e somente uma delas (1,3 por cento) apresentou uma malformação aparente ao nascimento (comunicação intraventricular). Nenhuma diferença quanto à idade na época da radioiodoterapia ou na concepção ou na dose de radioiodo foi observada entre as gravidezes com ou sem um desfecho favorável. CONCLUSÃO: Gravidezes que ocorrem 12 meses após terapia ablativa com radioiodo são seguras.

Testicular function after radioiodine therapy in patients with thyroid cancer.

Our aim was to assess testicular function in patients treated with high-dose radioiodine. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels were determined in 52 men with thyroid carcinoma before and 6, 12, and 18 months after radioiodine therapy (3.7-5.5 GBq (131)I; mean, 4.25 GBq (131)I) (group 1) and were also determined before and 18 months after the last radioiodine therapy in 22 patients who received high cumulative activities (13-27.7 GBq; mean, 20.3 GBq (131)I) (group 2). FSH levels were increased 6 months after therapy in all patients of group 1, while a decline was observed after 12 months, with 37 of 52 (71%) subjects presenting normal values. FSH values returned to normal after 18 months in all patients. In group 2, 12 of 22 (54.5%) patients presented elevated FSH and 8 (66%) of these individuals had oligospermia. Six months after radioiodine, increased LH levels were observed in only 5 of 52 (9.6%) patients of group 1, which returned to normal after 12 months, and in 5 of 22 (22%) of group 2. All patients showed normal testosterone levels. We conclude that 131I therapy may cause impairment of testicular function. A generally transient increase in FSH is highly common but is usually reversed within 18 months. Oligospermia was common (one third) after high cumulative (131)I activities. Becausee we did not perform a spermiogram before therapy, we cannot state that high cumulative (131)I activities cause permanent infertility. We recommend the routine use of sperm banks in the cases of men who still wish to have children and who will undergo therapy with (131)I activities of 14 GBq or more or in the case of patients with pelvic metastases.

Ablative treatment of thyroid cancer with high doses of 131I without pre-therapy scanning.

OBJECTIVE: To determine the success of ablative treatment using fixed high doses of 131I in patients with thyroid cancer. METHODS: A retrospective study was conducted on 274 patients who received ablative treatment without previous scanning, with the dose being based on surgical staging: stage I patients (tumour restricted to the thyroid) received 3.7 GBq, and stage II (lymph node metastases) and stage III patients (extra-thyroid invasion) were treated with 5.5 GBq. Successful treatment was defined as a negative control scan. RESULTS: One hundred and sixty patients were classified as stage I and 114 as stages II or III. Forty-six patients presented ectopic uptake on post-therapy scans (10% in stage I and 26% in stage II or III). Among stage I patients, the efficacy of treatment was 78.7%. A 47% failure rate was associated with metastases, and among patients without metastases who did not respond to treatment, thyroid bed uptake >5% on post-therapy scans was observed in 61%. Patients with stage II or III showed 62.2% efficacy. Twenty-three of the 43 (53%) unsuccessfully treated patients in this group had metastases and of the 20 patients without metastases, 14 (70%) presented thyroid bed uptake >5%. There were no differences between the responsive and non-responsive groups in terms of age, gender, histological type or size of the primary tumour. CONCLUSION: Empirical treatment presented 72% efficacy (higher in stage I) and failure was associated with the presence of metastases and large thyroid remnants; factors that can be evaluated by pre-therapy whole-body scanning.