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Tales Alvarenga Fagundes

Publications and source records attributed to Tales Alvarenga Fagundes.

14 recordsLinked to original sources
PubMed2006

[Recombinant TSH in ablative therapy and follow-up of patients with differentiated thyroid carcinoma].

The studies evaluating the efficacy and safety of recombinant TSH in the ablative therapy and follow-up of patients with differentiated thyroid carcinoma by serum thyroglobulin (Tg) measurement and iodine scanning were reviewed in this article. Recombinant TSH is comparable to hypothyroidism in the generation of Tg and in the execution of iodine-131 whole-body scanning, with the advantage of sparing patients from the symptoms of hypothyroidism and from impaired quality of life induced by levothyroxine withdrawal, in addition to a reduced exposure to elevated TSH and shorter absence from work, with recombinant TSH being the preparation indicated for the diagnosis of metastases in both low risk (Tg after recombinant TSH) and moderate or high risk patients (Tg and iodine-131 scanning after recombinant TSH). In the case of ablative therapy, the results are promising when using a dose of 100 mCi for remnant ablation, but hypothyroidism is still preferred, except for patients in whom the desired TSH elevation after levothyroxine withdrawal is not achieved, patients with base diseases that are aggravated by acute and severe hypothyroidism (severe heart and lung disease, coronary disease, compromised renal function, history of psychosis due to myxedema), patients debilitated by advanced disease, and elderly individuals. The studies also show that the administration of recombinant TSH is safe, with few mild or moderate adverse effects.

Carcinoma↗
PubMed2005

[Treatment of papillary microcarcinoma of the thyroid].

We retrospectively analyzed the recurrence, distant metastases and mortality of 78 patients with papillary microcarcinoma during a mean period of 6.8 years. None of the 56 patients with unifocal tumors without metastases relapsed, irrespective of the type of treatment (22 submitted to lobectomy, 11 to total thyroidectomy without ablation and 23 with ablation). The same occurred for the 15 cases of multicentric tumors restricted to the thyroid and treated with total thyroidectomy and radioiodine. Of the 7 patients with metastases in the initial presentation and treated with extensive surgery and ablative therapy, cervical recurrence was observed in 1 case. Detectable anti-thyroglobulin antibodies were more common after lobectomy (22.7% vs. 9%) and the specificity of thyroglobulin was compromised by this procedure, but not in patients submitted to total thyroidectomy without ablation. Two cases of definitive hypoparathyroidism were observed in the group submitted to total thyroidectomy (3.5%) and no cases with lobectomy. The present study agrees that lobectomy can be sufficient for the treatment of single microcarcinoma restricted to the thyroid. However, the Tg specificity is compromised. Total thyroidectomy is recommended for multicentric tumors or with lymph nodes metastases, but the routine use of radioiodine is a matter of controversy.

Carcinoma, Papillary↗
PubMed2005

[Revisiting serum thyroglobulin in the follow-up of patients with differentiated thyroid carcinoma].

This study analyzed serum thyroglobulin (Tg) during hypothyroidism in 207 patients with differentiated thyroid carcinoma treated with total thyroidectomy and radioiodine ablation and undetectable anti-Tg antibodies. Disease staging was defined by clinical examination, stimulated Tg, pre- and post-ablative radioiodine scanning, and other imaging methods (X-Ray, US, CT and MIBI-scan). The average interval from initial therapy was 2.3 years. 153 patients (74%) had no evident disease, 34 (16.4%) presented neck/mediastinal disease, and 20 (9.6%) had distant metastases (Mt). The best cut-off for Tg was 1 ng/ml, showing 100% sensitivity for distant Mt and 88.2% for local recurrence or lymph node Mt, and 88.8% specificity for any Mt and 74.8% for distant Mt. In patients with Tg <1 ng/ml, 2.8% showed cervical lymph nodes Mt. Cervical or mediastinal disease were 26% of cases with Tg between 1 and 5 ng/ml. Tg from 5 to 10 ng/ml was associated to distant Mt in 14.2% of the cases and others showed lymph nodes Mt. In patients with Tg >10 ng/ml, 51.3% presented distant Mt. We suggest the need for neck US even in cases with Tg <1 ng/ml. In addition, patients with Tg levels <5 ng/ml should be investigated by neck US and mediastinal CT only, and empirical therapy should be limited to patients with a minimum Tg level >5 ng/ml.

Adult↗
PubMed2005

Antithyroglobulin antibodies in patients with differentiated thyroid carcinoma: methods of detection, interference with serum thyroglobulin measurement and clinical significance.

Antithyroglobulin antibodies (TgAb) were measured using a chemiluminescent immunoassay (ICMA) and an agglutination test. TgAb laboratory and clinical interference with Tg measurements were assessed. The course of TgAb concentration and disease status were compared during 3 years after initial treatment. The agglutination test failed to detect all titers < 10 IU/mL (ICMA). Interference from TgAb was common at high titers, but even low antibody titers (< 5 IU/mL) were able to interfere with Tg measurement. Cases of distant metastases with undetectable Tg (by IRMA) and those apparently free of disease and without thyroid remnants with Tg> 2 ng/ml (by RIA) were identified among patients with TgAb. The exogenous Tg recovery test was normal (> 80%) by the two methods in 22% of patients with TgAb and confirmed laboratory interference. Absence of reduction in TgAb levels was a marker of persistent disease. In conclusion, TgAb should be determined by immunoassays; interference with Tg measurements occurred mainly but not always at high concentrations, with a normal Tg recovery test not excluding this interference. The behavior of TgAb is related to disease persistence or cure.

Adult↗
PubMed2005

Thyroglobulin before ablation and correlation with posttreatment scanning.

OBJECTIVES/HYPOTHESIS: To determine the usefulness of thyroglobulin (Tg) before ablation and the correlation with posttreatment scanning in patients with thyroid carcinoma. STUDY DESIGN: Prospective. METHODS: Tg during hypothyroidism was determined in 212 patients after thyroidectomy and before ablation. The disease stage was based on clinical examination, Tg, posttherapy scanning, other imaging methods, and histologic confirmation in selected cases. RESULTS: One hundred sixty-four patients presented thyroid remnants only, 31 had lymph node metastases, and 17 had distant metastases. Posttreatment scanning showed a sensitivity of 71% for lymph node and of 94.1% for distant metastases. Ectopic uptake was observed in 5.6% of patients with Tg less than 1 ng/mL, in 9% with levels from 1 to 5 ng/mL, in 10.7% with Tg from 5 to 10 ng/mL, and in 51% with Tg greater than 10 ng/mL. The sensitivity of Tg for metastases was 73 and 66.5% and specificity was 73 and 88.4% at a cut-off value of 5 and 10 ng/mL, respectively. CONCLUSIONS: Postoperative Tg less than 10 ng/mL rarely show distant metastases and because these metastases were observed in 31% of patients with values greater than 10 ng/mL, this criterion can be selected for the indication of imaging methods, in addition to neck ultrasound (US). For cases with Tg less than 10 ng/mL, US is necessary because even patients with undetectable Tg had lymph node metastases. The same cut-off can be used for the indication of radioiodine therapy even in the absence of any evidence of disease because 51% of the patients with Tg greater than 10 ng/mL showed ectopic uptake on posttreatment scanning.

Adolescent↗
PubMed2005

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.

Adult↗
PubMed2004

[Usefulness of radioiodine scanning in patients with moderate/high risk differentiated thyroid carcinoma in whom thyroglobulin after thyroxin withdrawal is undetectable after initial treatment].

We selected 92 patients without antithyroglobulin antibodies (TgAb), in whom thyroglobulin (Tg) after L-thyroxin withdrawal was undetectable (<1 ng/ml) 6-12 months after initial therapy and who were considered to be at moderate / high risk for recurrence by this criteria: age >45 years; tumor size >1.5 cm; and lymph nodes metastases in 43 (46.7%), local invasion in 26 (28.2%) or distant metastases in 23 (25%). Control whole-body scanning was negative in 78.2% of the cases and showed cervical uptake in the others. Cases presenting thyroid bed uptake in the absence of tumor recurrence did not receive radioiodine and Tg remained undetectable one year after the initial evaluation in all. Cervical uptake was not observed in 4/13 cases on repeated scan. In contrast, even in the absence of uptake and with undetectable Tg, 7 patients with recurrence confirmed by ultrasound (US) received surgical treatment. US showed 92.8% sensitivity for the detection of local-regional disease. The present study suggests that even moderate/high-risk patients without TgAb and with undetectable Tg levels (off T4) do not require radioiodine scanning after initial treatment and can be evaluated by cervical US.

Aged↗
PubMed2004

Post I-131 therapy scanning in patients with thyroid carcinoma metastases: an unnecessary cost or a relevant contribution?

RATIONALE: In patients with elevated serum thyroglobulin (Tg) and a negative whole-body scan (WBS), posttherapy scanning can reveal metastases in many cases and is therefore recommended. In contrast, the routine use of posttherapy scanning is questioned. MATERIALS AND METHODS: One hundred six patients with differentiated thyroid carcinoma had pre- and posttherapy scanning, with metastatic uptake on the diagnostic scan and were divided into 2 groups: 60 patients assessed on first ablation after thyroidectomy and 46 patients with tumor persistence or recurrence after initial ablative therapy. Data modifying the disease stage or treatment were considered to be clinically relevant. RESULTS: Posttherapy scanning on first ablation changed the disease stage in 8.3% of the patients and therapeutic approach in another 15%, and provided clinically relevant information for 26% of patients with 1 previous ablation. Even when excluding cases whose lesions were known by the time of the first postablative scan, the therapeutic approach was influenced by posttherapy scanning in 15.6% of the patients. Only 4 of 211 metastases detected on pretherapy WBS did not appear on postablative scans. CONCLUSIONS: Posttherapy scanning provides important information, even in patients whose pretherapy WBS is positive for metastases, with this approach being useful both during the first ablation and subsequent treatment.

Adolescent↗
PubMed2004

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.

Adenocarcinoma, Follicular↗