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Biomedical subjects

Leonardo Lamego Rezende

Publications and source records attributed to Leonardo Lamego Rezende.

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↗
PubMed2006

[Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy].

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.

Adenocarcinoma, Follicular↗
PubMed2006

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.

Abnormalities, Drug-Induced↗
PubMed2005

[Safety of radioiodine therapy in patients with thyroid carcinoma younger than 21 years].

We studied 20 patients with differentiated thyroid carcinoma undergoing radioiodine therapy (> or = 100 mCi dose) before the age of 21: 10 patients without distant metastases received a mean dose of 145 mCi and 10 with lung involvement received 270 mCi. One or more years after ablative therapy, xerostomia was present in two patients but was not accompanied by more severe complications such as oral ulcers or fissures, and 99mTcO4- scintigraphy confirmed salivary dysfunction. One patient showed keratoconjunctivitis sicca. Blood counts did not reveal abnormalities caused by radioiodine therapy. FSH was normal in 18 patients. Patients with elevated levels had received radioiodine just over a year ago and repetition of the exam after 6 months showed that FSH had returned to normal. The 6 male patients had normal LH and testosterone levels. Analysis did not reveal signs of pulmonary fibrosis secondary to treatment in the 10 cases with iodine-accumulating metastases in this organ. Our data suggest that ablative therapy employing a dose of 100 to 300 mCi is safe in young individuals, but persistent complications such as salivary dysfunction and conjunctivitis may occur.

Adolescent↗
PubMed2005

[Clinical manifestations and diagnosis of distant metastases of differentiated thyroid carcinoma after initial therapy].

We studied 58 patients with distant metastases of differentiated thyroid carcinoma diagnosed after initial therapy. Lymph node metastases were observed in 65% of the patients on initial presentation. All lymph node metastases, ninety percent of the lung metastases and only 25% of the bone metastases were asymptomatic. Radiography revealed lytic metastases in cases of bone involvement, was normal in 39.6% of the patients, and showed micrometastases in 34.5% and macrometastases in 25.8% of the patients with lung disease. Thyroglobulin (Tg) under thyroxine use was detectable in all patients without antibodies at a cut-off > 1 ng/ml, in 90% at > 5 ng/ml and in 80% at > 10 ng/ml, and after thyroxine withdrawal in 100% at a cut-off > 5 ng/ml and in 94% at > 10 ng/ml. In the case of patients with antibodies (13.8%), Tg was undetectable in half of them. Diagnostic scanning was positive in 83 and 77.6% of the patients with bone and lung metastases, respectively. After ablative therapy, the sensitivity was 100 and 93%, respectively. Eighty-five percent of patients with a negative diagnostic scan had lung metastases visible on radiographs. The determination of serum Tg is the best method in the follow-up of patients with differentiated thyroid cancer. Elevated Tg levels suggest the presence of metastases, indicating the need for ablative therapy with posttreatment scanning, which might reveal non-apparent metastases.

Adolescent↗
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

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

Ultrasonographic differentiation between metastatic and benign lymph nodes in patients with papillary thyroid carcinoma.

OBJECTIVE: The purpose of this study was to evaluate the ultrasonographic characteristics of metastatic lymph nodes in patients with papillary thyroid carcinoma. METHODS: The ultrasonographic characteristics of lymph nodes were analyzed in 112 consecutive patients who underwent thyroidectomy and lymph node dissection, with the diagnosis being confirmed by anatomopathologic examination. RESULTS: A total of 198 lymph nodes were metastatic, and 152 were benign (normal or with nonspecific lymphadenitis). Minimum axial diameters of 7 mm for level II (upper internal jugular chain) and 6 mm for the rest of the neck were observed in 93% of metastatic lymph nodes, absence of an echogenic hilum in 88%, hyperechogenicity in relation to the adjacent muscles in 86%, a round shape in 80%, calcifications in 49.5%, and intranodal cystic necrosis in 20%. These ultrasonographic characteristics were observed in 17%, 10%, 4.5%, 29.5%, 0%, and 0% of benign lymph nodes, respectively. CONCLUSIONS: Even basic ultrasonographic characteristics (shape, echogenicity and echogenic hilum, calcifications, and intranodal cystic necrosis) help in the differentiation between metastatic and nonmetastatic lymph nodes in patients with papillary thyroid carcinoma.

Adult↗
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↗