Avaliação retrospectiva do tratamento da dor óssea metastática com Samário-153-EDTMP

PURPOSE: The aim of this study was to evaluate the degree of metastatic bone pain palliation and medullar toxicity associated with samarium-153-EDTMP treatment. METHODS: Seventy-three patients with metastatic bone pain having previously undergone therapy with samarium-153-EDTMP (1 mCi/kg) were retrospectively evaluated. Routine follow-up included pain evaluation and blood counts for 2 months after treatment. Pain was evaluated using a subjective scale (from 0 to 10) before and for 8 weeks after the treatment. Blood counts were obtained before treatment and once a week for 2 months during follow-up. Dosimetry, based upon the urinary excretion of the isotope, was estimated in 41 individuals, and the resulting radiation absorbed doses were correlated with hematological data. RESULTS: Reduction in pain scores of 75% to 100% was obtained in 36 patients (49%), with a decrease of 50% to 75%, 25% to 50%, and 0% to 25% in, respectively, 20 (27%), 10 (14%), and 7 (10%) patients. There was no significant relationship between the pain response and location of the primary tumor (breast or prostate cancer). Mild to moderate myelosuppression was noted in 75.3% of patients, usually with hematological recovery at 8 weeks. The mean bone marrow dose was 347 ± 65 cGy, and only a weak correlation was found between absorbed dose and myelosuppression (Pearson coefficient = .4). CONCLUSIONS: Samarium-153-EDTMP is a valuable method for metastatic bone pain palliation. A mild to moderate and transitory myelosuppression is the main toxicity observed after samarium therapy, showing a weak correlation with dosimetric measures.OBJETIVO: O presente trabalho teve por objetivo avaliar o efeito paliativo da dor e a toxicidade medular associados ao tratamento com Samário-153-EDTMP em pacientes com metástases ósseas. MÉTODOS: O estudo foi realizado de forma retrospectiva, a partir do levantamento de prontuário de 178 pacientes submetidos a tratamento com 1mCi/kg de 153Sm-EDTMP devido à dor por metástases ósseas. Os prontuários de 73 pacientes foram considerados adequados para análise dos parâmetros clínicos (intensidade da dor) e laboratoriais (hemograma). A intensidade da dor foi avaliada em escala de 0 a 10 pelo próprio paciente, antes e durante 8 semanas após o tratamento. Hemograma completo foi realizado antes do tratamento e a cada semana nas 8 semanas seguintes. Estudos de dosimetria foram realizados em 41 dos 73 pacientes, baseados na excreção urinária e retenção do radioisótopo, sendo a dose de radiação absorvida correlacionada à toxicidade medular. RESULTADOS: Redução importante na intensidade da dor (diminuição de 75 a 100% do basal) foi constatada em 36 pacientes (49%), com redução de 50-75%, 25-50% e 0-25% em, respectivamente, 20 (27%), 10 (14%) e 7 (10%) casos. Não se observou variação significativa da resposta entre os pacientes com tumor primário de mama (n=29) ou de próstata (n=36). Toxicidade medular foi observada em 75,3% dos pacientes (71,2% com leucopenia e 53,4% com plaquetopenia), em geral de grau leve a moderado e com recuperação ao término da 8º semana. A dose média de medula foi de 347±65 cGy, havendo baixa correlação entre a dosimetria medular e a queda da contagem de leucócitos (coeficiente de correlação linear de 0,40) ou de plaquetas (coeficiente de correlação linear = 0,48). CONCLUSÕES: O tratamento com Samário-153-EDTMP permitiu um adequado controle da dor por metástases ósseas, com significativa redução na intensidade da dor. A toxicidade medular transitória foi a principal reação adversa observada, em geral de grau leve a moderado, apresentando baixa correlação com as medidas dosimétricas

Radioiodine therapy of differentiated thyroid cancer: radiologic impact of out-patient treatment with 100 to 150 mCi Iodine-131 activities

OBJETIVO: Determinar exposições decorrentes da radioiodoterapia ambulatorial do carcinoma diferenciado da tireoide (CDT) sobre os familiares dos pacientes e o meio ambiente. MÉTODOS: Administraram-se 100 a 150 mCi de (131I)NaI para tratamento ambulatorial de 20 pacientes com CDT. Monitorizaram-se com dosímetros termoluminescentes as doses de radiação recebidas por familiares (n = 27) e potenciais de dose nas residências. Também foram monitorizadas contaminação de superfície e rejeitos radioativos. RESULTADOS: Registraram-se doses < 1,0 mSv em 26 acompanhantes e 2,8 mSv em um caso, inferiores ao aceitável para exposições médicas (5,0 mSv/procedimento). Excetuando-se o quarto dos pacientes (média = 0,69 mSv), determinou-se potencial de dose nas residências < 0,25 mSv. A contaminação de superfícies (4,2 Bq.cm-2) não ultrapassou níveis de liberação, sem representar riscos mesmo em simulações do pior cenário. Os rejeitos radioativos tiveram volume de 2,5 litros e atividade estimada em 90 µCi (média = 4,5 µCi/paciente). CONCLUSÕES: Não foi constatado impacto radiológico ao meio ambiente ou aos familiares de pacientes tratados ambulatorialmente com 100 a 150 mCi de iodo-131 e acompanhados por profissionais qualificados.PURPOSE:To evaluate exposure and dosimetry to family members and environment due to outpatient radioiodine therapy of differentiated thyroid carcinoma. METHODS: Twenty patients were treated with 100-150mCi of iodine-131 on an out-patient basis. Family members dosimetry (n = 27) and potential doses inside the house were measured with thermoluminescent dosimeters. Surface contamination and radioactive wastes were also monitored. RESULTS: Less than 1.0 mSv doses were found in 26 co-habitants and 2.8 mSv in a single case (inferior to the acceptable value of 5.0 mSv/procedure). Potential doses in the houses were inferior to 0.25 mSv, excluding the patients bedroom (mean value = 0.69 mSv). Surface contamination (mean = 4.2 Bq.cm-2) were below clearance levels. Radioactive wastes generated had a volume of 2.5 liters and a total activity estimated in 90 µCi, with a calculated exposure close to the background radiation levels. CONCLUSIONS: No radiological impact was detected after iodine therapy with 100-150 mCi on an out-patient basis followed by experienced professionals.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Absence of mutations in PAX8, NKX2.5, and TSH receptor genes in patients with thyroid dysgenesis

Objectives: To precisely classify the various forms of TD, and then to screen for mutations in transcription factor genes active in thyroid development. Subjects and methods: Patients underwent ultrasound, thyroid scan, and serum thyroglobulin measurement to accurately diagnose the form of TD. DNA was extracted from peripheral leukocytes. The PAX8, and NKX2.5 genes were evaluated in all patients, and TSH receptor ( TSHR) gene in those with hypoplasia. Results: In 27 nonconsanguineous patients with TD, 13 were diagnosed with ectopia, 11 with hypoplasia, and 3 with athyreosis. No mutations were detected in any of the genes studied. Conclusion: Sporadic cases of TD are likely to be caused by epigenetic factors, rather than mutations in thyroid transcription factors or genes involved in thyroid development. Arq Bras Endocrinol Metab. 2012;56(3):173-7Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (Fapesp) [06/05800-1, 08/04786-0]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Etiology of congenital hypothyroidism using thyroglobulin and ultrasound combination

Methods currently employed to establish the etiology of congenital hypothyroidism include thyroid ultrasound and scintigraphic exams. Thyroglobulin is a protein almost exclusively secreted by thyroid tissue and indirectly reflects the amount of follicular cells. Even though thyroglobulin is easy to measure, it has been not frequently used because of discordant results to distinguish mainly athyreosis and ectopy (dysgenesis). Knowing the differences in inheritance and prognosis of thyroid dysgenesis and dyshormonogenesis, it is important to define the etiology of CH, combining tools that are easy, fast and available in most medical centers. Our objective was to evaluate and compare color Doppler ultrasound and serum thyroglobulin with radionuclide scan to define the etiology of congenital hypothyroidism. We evaluated 38 children above 3 years-old off-treatment that performed serum thyroglobulin by immunofluorometric assay, color Doppler ultrasound and radionuclide study. On color Doppler ultrasound, 11 patients had athyreosis, 5 ectopic glands, being I associated to hemiagenesis. Twenty one had topic thyroid (3 goiters, 10 normal, 8 hypoplastic). Hemiagenesis and cystic lesion were not revealed by radionuclide scan. We observed substantial agreement between color Doppler ultrasound and radionuclide scan (kappa=0.745, p<0.0001). Serum thyroglobulin in athyreosis ranged from <1.0 to 18.7 mu g/L. Patients with ectopic glands showed wider thyroglobulin range (4.5 to 123 mu g/L, median 28.4 mu g/L). Only one patient showed thyroglobulin deficiency. By using color Doppler ultrasound and serum thyroglobulin levels as valuable combined tools, we established the etiology of congenital hypothyroidism limiting excessive and harmful exams in children, like radionuclide scan.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[06/05800-1

É necessário reduzir as atividades de radioiodo nas terapias de pacientes com câncer de tireoide e disfunção renal?

The objective of this study were to obtain dosimetric data from a patient with thyroid cancer simultaneously undergoing peritoneal dialysis therapy, so as to determine the appropriate amount of 131I activity to be applied therapeutically. Percentages of radioiodine in the blood and the whole-body were evaluated, and radiation absorbed doses were calculated according to OLINDA/EXM software. Whole-body 131I effective half-time was 45.5 hours, being four times longer than for patients without any renal dysfunction. Bone-marrow absorbed dose was 0.074 mGy/MBq, with ablative procedure maintenance at 3.7 GBq, as the reported absorbed dose was insufficiently restrictive to change the usual amount of radioiodine activity administered for ablation. It was concluded that radioiodine therapeutic-dose adjustment, based on individual patient dosimetry, is an important way of controlling therapy. It also permits the safe and potential delivery of higher doses of radiation to tumors and undesirable tissues, with a minimum of malignant effects on healthy tissues.O objetivo do presente estudo foi determinar a atividade de radioiodo a ser administrada na terapia de um paciente portador de câncer de tireoide e simultaneamente tratado com diálise peritoneal. Percentuais de radioiodo em sangue e corpo-total foram avaliados após a administração de uma atividade traçadora e a dosimetria foi calculada utilizando o software OLINDA/EXM. A meia-vida efetiva do radioiodo em corpo-total foi de 45,5 horas, sendo quatro vezes maior que aquela observada em pacientes sem disfunção renal. A dose em medula óssea foi de 0,074 mGy/MBq, administrando-se uma atividade terapêutica de 3,7 GBq, uma vez que a estimativa de dose não foi suficientemente restritiva para mudar a atividade usual de radioiodo com função ablativa. Concluiu-se que a terapia individualizada de pacientes permite manter o equilíbrio entre o máximo de dose de radiação liberada em tumores ou tecidos indesejados com o mínimo de efeitos maléficos sobre tecidos sadio

Outpatient Radioiodine Therapy for Thyroid Cancer A Safe Nuclear Medicine Procedure

Purposes: To evaluate the dosimetric effect of outpatient radioiodine therapy for thyroid cancer in members of a patient`s family and their living environment, when using iodine-131 doses reaching 7.4 GBq. The following parameters were thus defined: (a) whole-body radiation doses to caregivers, (b) the production of contaminated solid waste, and (c) radiation potential and surface contamination within patients` living quarters. Methods: In total, 100 patients were treated on an outpatient basis, taking into consideration their acceptable living conditions, interests, and willingness to comply with medical and radiation safety guidelines. Both the caregivers and the radiation dose potentiality inside patients` residences were monitored by using thermoluminescent dosimeters. Surface contamination and contaminated solid wastes were identified and measured with a Geiger-Muller detector. Results: A total of 90 monitored individuals received a mean dose of 0.27 (+/- 0.28) mSv, and the maximum dose registered was 1.6 mSv. The mean value for the potential dose within all living quarters was 0.31(+/- 0.34) mSv, and the mean value per monitored surface was 5.58 Bq/cm(2) for all the 1659 points measured. The overall production of contaminated solid wastes was at a low level, being about 3 times less than the exemption level indicated by the International Atomic Energy Agency. Conclusions: This study indicates that the treatment of thyroid cancer by applying radioiodine activities up to 7.4 GBq, on an outpatient basis, is a safe procedure, especially when supervised by qualified professionals. This alternative therapy should be a topic for careful discussion considering the high potential for reducing costs in healthcare and improving patient acceptance.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[08/54179-3

Could the treatment of differentiated thyroid carcinoma with 3.7 and 5.55 GBq of ((131)I)NaI, on an outpatient basis, be safe?

Objectives The first objective of this study was to evaluate the radiological impact on relatives and the environment because of outpatient treatment of differentiated thyroid carcinoma with 3.7 and 5.55 GBq of ((131)I)NaI. The second objective was to determine, analyze, and evaluate whole-body radiation dose to caregivers, the production of contaminated solid waste, and the potentiality of radiation dose and surface contamination existing inside patients` households. Methods Twenty patients were treated on an outpatient basis, taking into consideration their acceptable living conditions, interests, and willingness to comply with medical and radiation-safety guidelines. The caregivers themselves, as well as the potentiality of the radiation dose inside patients` residences, were monitored with a thermo-luminescence dosimeter. Surface contamination and contaminated solid wastes were identified and measured by using a Geiger-Muller detector. Results and discussion Twenty-six monitored individuals received accumulated effective radiation doses of less than 1.0 mSv, and only one 2.8 mSv, throughout the 7 days of measurement. The maximum registered value for the potential of radiation dose inside all living areas was 1.30 mSv. The monitored surface contamination inside patients` dwellings showed a mean value of 4.2 Bq/cm(2) for all surfaces found to be contaminated. A total of 2.5l of contaminated solid waste was generated by the patients with 3.33 MBq of all estimated activity. Conclusion This study revealed that the treatment of differentiated thyroid carcinoma with 3.7 and 5.55 GBq of ((131)I)NaI, on an outpatient basis, can be safe when overseen by qualified professionals and with an adapted radiation-protection guideline. Even considering the radioiodine activity level and the dosimetric methodology applied here, negligible human exposure and a nonmeasurable radiological impact to the human environment were found. Nucl Med Commun 30:533-541 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.FAPESP - Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[06/61556-2