Marília Martins Silveira Marone

One Month Is Sufficient for Urinary Iodine to Return to Its Baseline Value After the Use of Water-Soluble Iodinated Contrast Agents in Post-Thyroidectomy Patients Requiring Radioiodine Therapy

BACKGROUND There is a concern regarding the use of iodinated contrast agents (ICA) for chest and neck computed tomography (CT) to localize metastatases in patients with differentiated thyroid cancer (DTC). This is because the iodine in ICA can compete with (131)I and interfere with subsequent whole scans or radioactive iodine treatment. The required period for patients to eliminate the excess iodine is not clear. Therefore, knowing the period for iodine levels to return to baseline after the injection of ICA would permit a more reliable indication of CT for DTC patients. The most widely used marker to assess the plasmatic iodine pool is the urinary iodine (UI) concentration, which can be collected over a period of 24 hours (24U) or as a single-spot urinary sample (sU). As 24U collections are more difficult to perform, sU samples are preferable. It has not been established, however, if the measurement of iodine in sU is accurate for situations of excess iodine. METHODS We evaluated 25 patients with DTC who received ICA to perform chest or neck CT. They collected 24U and sU urinary samples before the CT scan and 1 week and 1, 2, and 3 months after the test. UI was quantified by a semiautomated colorimetric method. RESULTS Baseline median UI levels were 21.8 μg/dL for 24U and 26 μg/dL for sU. One week after ICA, UI median levels were very high for all patients, 800 μg/dL. One month after ICA, however, UI median levels returned to baseline in all patients, 19.0 μg/dL for 24U and 20 μg/dL for sU. Although the values of median UI obtained from sU and 24U samples were signicantly different, we observed a significant correlation between samples collected in 24U and sU in all evaluated periods. CONCLUSION One month is required for UI to return to its baseline value after the use of ICA and for patients (after total thyroidectomy and radioiodine therapy) to eliminate the excess of iodine. In addition, sU samples, although not statistically similar to 24U values, can be used as a good marker to evaluate patients suspected of contamination with iodine.

Correction factors for more accurate estimates of exposure rates near radioactive patients : Experimental, point, and line source models

Radioactive patients may expose others after radiopharmaceutical administrations, and evaluation of the absorbed dose or exposure rates close to patients is important in keeping radiation doses as low as reasonably achievable. Two theoretical exposure models, point source and line source models, are frequently used to calculate exposure or dose rates without the support of actual measurements. If measurements of exposure rates were performed near patients, an experimental exposure model could be implemented. When measurements of exposure rates are performed, these measurements are made inside therapy rooms or other confined places, in which case scattered radiation may significantly influence the measurements. In this study we measured exposure rates from radioactive patients without the influence of scattered radiation and determined correction factors for the theoretical exposure models. The exposure rates from a total of 110 radioactive patients were measured at 1.0 h after oral administration of Na131I for thyroid therapy; the results ±1 SD at distances of 0.5, 1.0, 1.5, 2.0, 3.0, and 4.0 m in front of the patients were (29 ± 6), (9.9 ± 1.7), (4.6 ± 0.9), (2.7 ± 0.5), (1.31 ± 0.25) and (0.74 ± 0.12) × 10−10 C kg−1 MBq−1 h−1 [1.0 × 10−10 C kg−1 MBq−1 h−1 = 14.34 × 10−6 R mCi−1 h−1], respectively. To obtain more accurate estimates of the actual exposure rates from patients using the theoretical exposure models, we found that correction factors should be applied; the functions CFEM = 1.19 + 32.80e−5.92D and CFLS = 0.022Ln(D) + 0.639 describe these correction factors for distances less than or equal to 1.0 m from the patients for experimental and line source exposure models, respectively. The function that describes the correction factors to the point source model is CFPS = 0.224Ln(D) + 0.638 at the same distances; applying these correction factors leads to a reduction from 56% to 1% in the difference between measured exposure rates and theoretical exposure rates calculated by the point source exposure model at a distance of 1.0 m from patients. The results given here provide more accuracy in evaluation of exposure rates and consequently absorbed doses near radioactive patients and allow for more effective radiological protection procedures during patient management.

Tratamento do carcinoma diferenciado da tireóide com iodo-131: intervenções para aumentar a dose absorvida de radiação

OBJECTIVES Our aim was to analyze measures taken to increase the radiation absorbed dose (DOSE) during treatment of well-differentiated thyroid cancer (DTC) with iodine-131. METHODS An increase in DOSE is achieved by: avoiding competition with non-radioactive iodine, stimulating cellular uptake/retention, increasing the administered activity. Basis and results of each one of these methods were reviewed. RESULTS Although it is difficult to demonstrate an increase in survival, there is a direct relation between DOSE and tumoral response in DTC. Different approaches can be used aiming an increase in DOSE, with a possible improvement in tumoral response for treatment with iodine-131. Although DTC is a relatively benign disease, a better response to treatment is highly desirable in high-risk patients, who have few other options of therapy. CONCLUSIONS An increase in DOSE during treatment of DTC can be achieved using the described interventions, which should be used in high-risk cases of DTC.

Physical exercises with free weights and elastic bands can improve body composition parameters in postmenopausal women: WEB protocol with a randomized controlled trial.

Objective:The aim of this study was to assess the impact of a program of supervised physical exercises (WEB protocol) versus home-based exercises on body composition (lean mass and fat mass) in postmenopausal women. Methods:The initial sample comprised 60 women who were randomized into two groups. After exclusion, the final randomized sample included a supervised group (n = 16; mean age, 66.4 ± 6.5 y) and a home group (n = 18; mean age, 68.2 ± 6.0 y). Both groups underwent a 12-month intervention with physical exercises, including muscle impact exercises and strength and stretching consisting of two weekly sessions of 60 minutes. Body composition was determined by densitometry. Results:The supervised group exhibited increased lean mass in the upper limbs (P = 0.003) and lower limbs (P = 0.011), total lean tissue (P = 0.015), and appendicular lean mass index (P = 0.001) compared with baseline. The home group exhibited no differences in the lean mass assessments. Conclusions:Our results suggest that regular supervised physical exercises with free weights and elastic bands can promote greater improvements in lean body mass than unsupervised exercises in postmenopausal women.

Regression of orbital brown tumor after surgical removal of parathyroid adenoma

Brown tumors are rare skeletal manifestations that occur in less than 2% of primary hyperparathyroidism (PHPT) cases. Even rarer is the occurrence of brown tumor of the orbit, and few cases have been reported around the world. The rare instance of this benign tumor has prompted us to report the case and treatment of an orbital brown tumor in a patient with PHPT caused by parathyroid adenoma. We present the case of a patient undergoing follow-up at a referral center. The 60-year-old female patient, presented herself with progressive swelling in the nasal region, epistaxis and proptosis, she had noticed seven months prior to our examination. Multiple imaging and laboratory findings revealed parathyroid hormone (PTH)-dependent hypercalcemia (total calcium = 14.3 mg/dL and PTH = 1,573 pg/mL), a nodular lesion in the upper pole of the left thyroid lobe and increased uptake in left upper cervical region. The patient underwent left superior parathyroidectomy in September 2011, which led to the normalization of hypercalcemia and regression of the orbital tumor, as seen on control CT scan. This case highlights the spontaneous regression of the brown tumor after surgical management of the parathyroid adenoma.

Acute effects of radioiodine therapy on the voice and larynx of Basedow-Graves patients

UNLABELLED Gravess disease is the most common cause of hyperthyroidism. There are three current therapeutic options: anti-thyroid medication, surgery, and radioactive iodine (I 131). There are few data in the literature regarding the effects of radioiodine therapy on the larynx and voice. The aim and the AIM os this study was: to assess the effect of radioiodine therapy on the voice of Basedow-Graves patients. MATERIAL AND METHOD A prospective study was done. Following the diagnosis of Graves disease, patients underwent investigation of their voice, measurement of maximum phonatory time (/a/) and the s/z ratio, fundamental frequency analysis (Praat software), laringoscopy and (perceptive-auditory) analysis in three different conditions: pre-treatment, 4 days, and 20 days post-radioiodine therapy. Conditions are based on the inflammatory pattern of thyroid tissue (Jones et al. 1999). RESULTS No statistically significant differences were found in voice characteristics in these three conditions. CONCLUSION Radioiodine therapy does not affect voice quality.

Efeitos agudos laringológicos e vocais da radioiodoterapia em pacientes com hipertireoidismo por doença de Basedow Graves

A Doenca de Graves constitui a forma mais comum de hipertireoidismo e tres abordagens terapeuticas sao atualmente utilizadas: uso de medicamentos antitireoideanos, cirurgia e iodo radioativo (I 131). Os efeitos do o I 131 e a inducao precoce de hipotireoidismo sao consequencias da destruicao induzida do I131 sobre o parenquima tireoideano. Sao poucos relatos encontrados na literatura acerca dos efeitos da radioioterapia sobre a laringe e consequentemente na producao vocal. OBJETIVO: Avaliar os efeitos agudos sobre a voz da radioiodoterapia em pacientes com hipertireoidismo por Doenca de Basedow Graves. MATERIAL E METODO: Estudo de corte contemporâneo longitudinal, prospectivo. Procedimentos: Investigacao vocal, mensuracao do tempo maximo fonatorio de /a/ e relacao s/z, analise frequencia fundamental (Software Praat), laringoscopia e analise perceptivo-auditiva em tres momentos: pre-dose, 4 dias e 20 dias pos dose. Momentos baseados no perfil inflamatorio do tecido tireoideano. RESULTADOS: Nao houve mudancas estatisticamente significantes nos aspectos vocais e laringologicos nos tres momentos avaliados. CONCLUSAO: A radioiodoterapia nao afeta a qualidade vocal.

Carcinoma de tireóide na infância e adolescência

Approximately 10% of thyroid cancers are present in patients less than 21 years of age, representing 3% of all cancers of children and adolescents, with predominance in females 2:1 in relation to males. Thyroid cancers in this age group are usually papillary (90%), bilateral, multifocal and bigger in size compared to adults. Capsule invasion and lymphatic and pulmonary metastases are more frequent in children. Radiation sensitivity seems to represent an important factor in prepubertal patients. Familial history is reported in 5% of the cases. Genes such as RET/PTC, RAS and BRAF are usually involved in thyroid carcinogenesis in this age group. Cervical adenomegaly is a common clinical presentation, but does not represent a poor prognostic factor in children. Ultrasound and fine needle aspiration biopsy are valuable diagnostic procedures. Surgery is the preferred treatment including thyroidectomy and ganglionary excision, followed by ablative radioiodine therapy. L-thyroxine replacement with suppressive dosage should be employed targeting chronic TSH suppression. Long-term prognosis is usually better in children when compared with adults. Plasma thyroglobulin measurement is also useful to detect residual thyroid cancer disease.

Critérios semiquantitativos de análise da linfocintilografia em linfedema dos membros inferiores

OBJETIVO: Avaliar se diferentes parâmetros de analise da linfocintilografia permitem a distincao entre membros com e sem linfedema em pacientes com quadro clinico de edema unilateral. METODOS: Levantamento retrospectivo dos exames de 20 pacientes submetidos a linfocintilografia para investigacao de edema unilateral de membros inferiores, divididos em pacientes com linfedema primario (grupo 1, n = 7) ou secundario pos-traumatico (grupo 2, n = 13). Foi realizada linfocintilografia apos injecao subdermica de soroalbumina humana marcada com tecnecio-99m nos pes, com imagens da regiao inguinal durante 15 min e imagens dos membros inferiores apos 15 min e 1 h. Os parâmetros analisados foram: tempo de aparecimento da cadeia inguinal, indice semiquantitativo (fluxo linfatico, difusao intersticial, aspecto dos vasos, tempo de aparecimento e aspecto dos linfonodos inguinais) e inclinacao da curva de atividade em funcao do tempo da regiao inguinal. As medidas nos membros clinicamente acometidos foram comparadas aos membros sem linfedema em ambos os grupos. RESULTADO: O tempo medio de aparecimento da cadeia inguinal e o indice semiquantitativo foram significativamente maiores nos membros com linfedema que nos membros sem linfedema quando considerados todos os pacientes, com maior retardo e indice semiquantitativo nos membros com linfedema do grupo 1 em relacao aos do grupo 2. CONCLUSAO: A analise do tempo de aparecimento da cadeia inguinal e o indice semiquantitativo fornecem parâmetros objetivos de avaliacao do linfedema que podem auxiliar na deteccao e seguimento dos pacientes com linfedema.

Thyroglobulin levels before radioactive iodine therapy and dynamic risk stratification after 1 year in patients with differentiated thyroid cancer

OBJECTIVES We sought to assess the relationship between stimulated thyroglobulin (sTg) before radioactive iodine therapy (RIT), and the dynamic risk stratification 1 year after treatment, and to establish the utility of the sTg as a predictor of response to therapy in these patients. A retrospective chart review of patients with differentiated thyroid cancer (DTC) who underwent RIT after surgery and were followed for at least 1 year, was carried out. SUBJECTS AND METHODS Patients were classified according to the dynamic risk stratification 1 year after initial treatment. The sTg values before RIT were compared among the groups. ROC curve analysis was performed. RESULTS Fifty-six patients were enrolled (mean age 44.7 ± 14.4 years, 80.7% had papillary carcinoma). Patients with excellent response had sTg = 2.1 ± 3.3 ng/mL, those with indeterminate response had sTg = 8.2 ± 9.2 ng/mL and those with incomplete response had sTg = 22.4 ± 28.3 ng/mL before RIT (p = 0.01). There was a difference in sTg between excellent and incomplete response groups (p = 0.009) while no difference was found between indeterminate and either excellent or incomplete groups. The ROC curve showed an area under the curve of 0.779 assuming a sTg value of 3.75 ng/mL. CONCLUSION Our study results suggest that the higher the sTg before RIT, the greater the likelihood of an incomplete response to initial treatment. A sTg cut-off of 3.75 ng/mL was found to be a good predictor of response to initial treatment in patients with DTC.