El tratamiento paciente específico del hipertiroidismo con radioyodo: una oportunidad a la mejora / Radioiodine treatment of hyperthyroidism with patient-specific techniques: an improvement opportunity

Introducción: La aplicación de actividades fijas en el tratamiento del hipertiroidismo con I131 (yoduro de sodio, conocido también como radioyodo), es el método más usado en nuestro país, a pesar de la individualidad morfo-funcional que caracteriza esta afección. Sin embargo, no existe aún, un consenso internacional sobre la dosis más conveniente para cada caso, y por ende, los resultados no siempre son los deseados. Objetivo: Evaluar la aplicabilidad de varios métodos de cálculo de dosis paciente-específica para el tratamiento de hipertiroidismo con yoduro de sodio. Métodos: Se realizó un análisis de los resultados de varios métodos de cálculo de dosis recomendados internacionalmente a partir de la actividad fija prescrita en 10 pacientes, con el empleo de tecnologías y herramientas ya desarrolladas y disponibles en el país. Se evaluó la variabilidad inter-especialista y su impacto en la dosis planificada para el tratamiento. Resultados: El uso de la información incompleta de la biodistribución y farmacocinética del paciente produjo diferencias entre -42 por ciento y 37 por ciento de las dosis para el mismo paciente. El resultado de la comparación del método de cálculo recomendado por la Sociedad Europea de Medicina Nuclear, manejando la masa por gammagrafía-2D / 3D y por ultrasonido, arrojó diferencias no significativas entre sí. La variabilidad inter-especialista de las actividades prescrita mostró diferencias significativas, que arrojan sobre el mismo paciente, discrepancias entre 44Gy y 243Gy de las dosis terapéuticas a recibir, situación que puede comprometer el éxito del tratamiento y producir efectos secundarios no deseados. Conclusiones: Las técnicas dosimétricas paciente-específicas se pueden implementar satisfactoriamente en nuestro país. Las diferencias numéricas encontradas, especialmente la variabilidad inter-especialista, demuestran la no estandarización terapéutica, lo que apoya el uso de la farmacocinética paciente-específica pre terapéutica y la masa por gammagrafía-3D para planificar el tratamiento siempre que sean posible(AU)

Introduction: Despite of its typical morpho-functional individuality, fixed activities remain as the most used method in Cuba for hyperthyroidism treatment with I (sodium iodide, also known as radioiodine). However, there is not yet an international consensus on the most convenient doses for each case, so, the results are not always the desired ones. Objective: To evaluate the applicability of various patient-specific dose calculation methods for the treatment of hyperthyroidism with sodium iodide. Methods: It was carried out an analysis in 10 patients of the results of some methods for dose calculation from the prescribed fixed activity recommended internationally, with the use of technologies and tools already developed and available in the country. The inter-specialist variability and its impact in the planned dose for the treatment were assessed. Results: The use of uncompleted biodistribution and pharmacokinetics information of the patient showed differences between -42 percent and 37 percent in the doses for the same patient. The outcome of the comparison of the calculation method recommended by the European Society of Nuclear Medicine managing the mass by 3D/2D gammagraphy and ultrasound, presented no significant discrepancies among them. The inter-specialist variability of prescribed activity was statistically significant, and it can produce in the same patient differences between 44Gy and 243Gy of the therapeutic doses, which could affect the treatment success and lead to unnecessary side effects. Conclusions: The patient´s personalized calculation methods can be satisfactorily applied in Cuba. The numeric differences found, especially inter-specialist variability, show the lack of therapeutic standardization, which supports the use of pre-therapeutic patient-specific pharmacokinetics and the mass by 3D-gammagraphy to plan the treatment when possible(AU)

La cirugía en el tratamiento de la crisis tirotóxica / Surgery for the Treatment of Thyrotoxic Crisis

RESUMEN La crisis tirotóxica es una complicación de la tirotoxicosis mal tratada y se asocia con una elevada mortalidad. Requiere tratamiento médico urgente en unidades de cuidados intensivos. Mujer de 42 años, con antecedentes personales de hipertensión arterial y nódulo tiroideo hiperfuncionante desde hace 18 años, con abandono del tratamiento médico hace dos años, que acude a urgencias con disnea paroxística nocturna, taquicardia, hipertensión arterial, gran bocio y anasarca. Ingresa en la unidad de cuidados intensivos con diagnóstico de crisis tirotóxica e inicia el tratamiento médico con medidas de soporte precisas, la que incluye intubación orotraqueal. Debido a la dificultad de manejo clínico y respiratorio de la paciente, se decide realizar tratamiento quirúrgico urgente. Se practica una tiroidectomía total de bocio multinodular parcialmente intratorácico y una traqueostomía preventiva. El resultado de anatomía patológica fue: bocio multinodular tóxico. La paciente fue dada de alta con función tiroidea normal, cierre de traqueostomía y buena fonación, tras mes y medio de hospitalización. A pesar de que un tratamiento médico conservador es el adecuado de la tirotoxicosis, los síntomas y signos sistémicos de la crisis tirotóxica y sus manifestaciones órgano-específicas, asociados a una persistente dificultad respiratoria por síntomas compresivos derivados del gran bocio, se consideró que la tiroidectomía urgente en este caso estaba indicada, dato que se corroboró ante la buena evolución posoperatoria. El tratamiento de la tirotoxicosis es fundamentalmente clínico, sin embargo, la cirugía puede ser útil ante la dificultad en el manejo clínico(AU)

Abstract The thyrotoxic crisis is a complication of poorly treated thyrotoxicosis and is associated with high mortality. This condition requires urgent medical treatment in intensive care units. A 42-year-old woman, with a personal history of high blood pressure, hyperfunctioning thyroid nodule for 18 years, and abandonment of medical treatment since two years ago, presented to the emergency department with paroxysmal nocturnal dyspnea, tachycardia, high blood pressure, large goiter, and anasarca. She was admitted into the intensive care unit with a diagnosis of thyrotoxic crisis and started to receive medical treatment under precise support measures, including orotracheal intubation. Due to the patient's difficult clinical and respiratory management, it was decided to perform urgent surgical treatment. She was performed a total thyroidectomy of partial intrathoracic multinodular goiter and a preventive tracheostomy. The result of pathological anatomy was toxic multinodular goiter. The patient was discharged with normal thyroid function, tracheostomy closure, and good phonation, after a month and a half of hospitalization. Despite the fact that conservative medical treatment is the adequate one for thyrotoxicosis, the systemic symptoms and signs of the thyrotoxic crisis, and its organ-specific manifestations, associated with persistent respiratory distress due to compression symptoms derived from large goiter, urgent thyroidectomy needed to be indicated in this case, a fact corroborated after good postoperative evolution. The treatment of thyrotoxicosis is fundamentally clinical; however, surgery can be useful given the difficulty in clinical management(AU)

Recombinant human thyrotropin stimulation prior to 131I therapy in toxic multinodular goitre with low radioactive iodine uptake. / La estimulación previa con rhTSH mejora la respuesta al tratamiento con radioyodo en pacientes con bocio multinodular tóxico de baja captación.

AIM: Stimulation with recombinant human thyrotropin (rhTSH) increases thyroid radioiodine uptake, and is an aid to 131I therapy in non-toxic multinodular goitre (MNG). However, there are not many studies using rhTSH prior to 131I in toxic multinodular goitre to improve hyperthyroidism and compressive symptoms. MATERIAL AND METHOD: A prospective study was conducted on patients with MNG and hyperthyroidism. Patients were recruited consecutively and divided into group I, stimulated with 0.3mg of rhTSH before radioiodine therapy, and a control group or group II, without stimulation. Thyroid function, radioiodine thyroid uptake, thyroid weight, and compressive symptoms were measured, and patients were followed-up for 9 months. RESULTS: Group I consisted of 16 patients (14 women), with a mean age 69.7 years, and group II with 16 patients (12 women), with a mean age 70.7 years. After stimulation with 0.3mg rhTSH in group I, 131I uptake (RAIU) at 24h increased by 78.4%, and the estimated absorbed dose by 89.3%. In group II, the estimated absorbed dose was lower than group I after stimulation with rhTSH (29.8Gy vs. 56.4Gy; P=0.001). At 9 months of follow-up, hyperthyroidism was controlled in 87.5% of patients in group I, and 56.2% in group II (P=0.049). The mean reduction in thyroid weight was higher in group I than in group II (39.3% vs. 26.9%; P=0.017), with a tendency towards subjective improvement of compressive symptoms in group I, although non-significant. Only 2 patients described tachycardias after rhTSH administration, which were resolved with beta-blockers. CONCLUSION: Stimulation with 0.3mg of recombinant human thyrotropin prior to radioiodine therapy achieves a reduction in thyroid weight and functional improvement in patients with hyperthyroidism and multinodular goitre with low uptake, and with no need for hospital admission.

Avaliação da eficácia do I¹³¹ no tratamento de pacientes com bócio nodular tóxico / I¹³¹ Evaluation of the efficacy of the treatment of patients with toxic nodular goiter

Introdução: O Bócio Multinodular Tóxico e o Adenoma Tóxico constituem, depois da doença de Graves, nas principais causas de hipertireoidismo. As modalidades terapêuticas são terapia ablativa com I131 e cirurgia. A escolha do tratamento depende da idade, comorbidades e sintomas compressivos. O tratamento ablativo com I131 é um método não invasivo, seguro e com alta eficácia na resolução do hipertireoidismo. Objetivos: Avaliar retrospectivamente a eficácia das doses do I131 administradas no tratamento do hipertireoidismo de pacientes com BMNT e AT do Serviço de Endocrinologia do HSPM. Métodos: Foram revisados 27 prontuários de pacientes que receberam I131 e foram acompanhados por 6 meses. Analisamos o tempo de normalização do TSH, o status tireoidiano, a redução do volume do bócio ou nódulo e a necessidade de 2a dose de radioiodo. Resultados: O tempo médio para normalização do TSH foi de 56,3 ± 19,6 dias no grupo BMNT e 59,7 ± 14 no grupo AT. Houve redução de 36,5% no volume tireoidiano no grupo BMNT e 45,9% no diâmetro do nódulo no grupo AT. 100% dos pacientes entraram em remissão e nenhum paciente necessitou de segunda dose de radioiodo ao 6o mês. Apenas 5% dos pacientes com BMNT e nenhum com AT evoluíram para hipotireoidismo.Conclusão: A terapia com I131 na dose média de 30,35 mCi (BMNT) e 32,4 mCi (AT) é eficaz, levando 100% dos pacientes à remissão ao final de 6 meses, além de apresentar benefício na redução do bócio ou nódulo (AU)