Clinical outcomes of low and intermediate risk differentiated thyroid cancer patients treated with 30mCi for ablation or without radioactive iodine therapy

ABSTRACT Objective To retrospectively evaluate the outcomes of patients with low and intermediate risk thyroid carcinoma treated with total thyroidectomy (TT) and who did not undergo radioiodine remnant ablation (RRA) and to compare them to patients receiving low dose of iodine (30 mCi). Subjects and methods A total of 189 differentiated thyroid cancer (DTC) patients treated with TT followed by 30mCi for RRA or not, followed in two referral centers in Brazil were analyzed. Results From the 189 patients, 68.8% was ATA low-risk, 30.6% intermediate and 0.6% high risk. Eighty-seven patients underwent RRA and 102 did not. The RRA groups tended to be younger and had a higher frequency of extra-thyroidal extension (ETE). RRA did not have and impact on response to initial therapy neither in low (p = 0.24) nor in intermediate risk patients (p = 0.66). It also had no impact on final outcome and most patients had no evidence of disease (NED) at final follow-up. Recurrence/persistence of disease was found in 1.2% of RRA group and 2% in patients treated only with TT (p = 0.59). Conclusions Our study shows that in low and intermediate-risk patients, RRA with 30 mCi seems to have no major advantage over patients who did not undergo RRA regarding response to initial therapy in each risk group and also in long term outcomes.

Fosfato de cromo (III) marcado con diferentes radionúclidos para uso en radiosinoviortesis / Chromium (III) labelled with several radionuclidesphosphate for use in radiosynoviothersis

Introducción: la radiosinoviortesis se utiliza en el tratamiento de la sinovitis crónica, complicación frecuente en enfermedades sistémicas como artritis reumatoide y hemofilia. En la práctica clínica internacional se emplean diferentes coloides y suspensiones radiactivas, pero su número es reducido y su disponibilidad limitada. Objetivo: obtención y caracterización físico-química de suspensiones de fosfato de cromo (III) marcadas con radionúclidos como potenciales radiofármacos para uso en radiosinoviortesis. Métodos: las suspensiones se obtuvieron por síntesis química, los radionúclidos se añadieron al inicio de la reacción o después de finalizada esta. El tamaño de partículas se estimó mediante microscopia óptica y filtración por membranas. Asimismo se evaluó por espectrofotometría la estabilidad de la suspensión al ser resuspendida en distintos medios. La pureza radioquímica se determinó por cromatografía de papel. Resultados: se obtuvo y caracterizó una suspensión de fosfato de cromo (III). El producto obtenido presentó un tamaño de partículas predominante entre 0,8-5 µm y que al ser suspendidas en solución de gelatina al 2 por ciento en tampón acetato 1 mg/mL no sedimentó en menos de 3 h. Se estableció la tecnología para la obtención de formulaciones de fosfato de cromo (III) marcado con 32P e 90Y y se demostró la factibilidad de marcar la suspensión obtenida con otros radionúclidos trivalentes como 177Lu y 68Ga. Conclusiones: los resultados permiten considerar al fosfato de cromo (III) una suspensión base para la obtención de radiofármacos para uso en radiosinoviortesis en diferentes articulaciones, en función de las características físico-nucleares de los radionúclidos que se empleen

Introduction: radiosynoviorthesis is used in treating chronic synovitis, a frequent complication of some systemic diseases as rheumatoid arthritis and hemophilia. There are different colloids and radioactive suspensions recommended in the international clinical practice, but the number is reduced and the availability limited. Objective: obtaining and physical-chemical characterization of suspensions of chromium phosphate (III) labeled with several radionuclides as potential radiopharmaceuticals for using in radiosynoviorthesis. Methods: the suspensions were obtained by chemical synthesis. Radionuclides were added at the beginning or after concluding the reaction. The particle size was estimated by means of optic microscopy and membrane filtration. Similarly, the stability of suspension when re-suspended in several media was evaluated by spectrophotometry. The radiochemical purity was determined by paper chromatography. Results: a suspension of chromium (III) phosphate was obtained and characterized. It was found that the obtained product had a predominant particle size range of 0,8 to 5 µm and that when suspended in 2 percent gelatin solution in 1mg/ml acetate buffer, it settled in no less than 3 hours. Technologies for the preparation of radiopharmaceuticals of Chromium (III) Phosphate labeled with 32P and 90Y were described. There was demonstrated the feasibility of labeling the obtained suspension with other trivalent radionuclides such as 177Lu and 68Ga. Conclusions: the results allow considering the obtained Chromium (III) Phosphate suspension as a matrix for the preparation of radiopharmaceuticals to be used in radiosinoviorthesis aimed at various joints, depending on the physical and nuclear characteristics of the radionuclides

Radiosinovectomía de muñeca guiada por ultrasonido: experiencia de un caso clínico y revisión del tema / Ultrasound-guided wrist radiosynovectomy: case report and topic review

Radiosynovectomy is a local form of radiotherapy used as second-line treatment in the management of inflammatory and non-inflammatory arthropathies with unsatisfactory response to local or systemic corticosteroid therapy. Its efficacy is similar to that of surgical synovectomy, with the advantages of being a low-cost and minimally- invasive treatment that requires a shorter recovery time. Its efficacy is greater in the treatment of inflammatory arthritis characterized by synovitis, such as rheumatoid arthritis and juvenile chronic arthritis with mono/oligoarticular involvement, especially in upper extremity joints. A number of isotopes can be used in colloidal suspensions. Rhenium-186-sulphide colloid is currently indicated for the treatment of medium-sized joints. The ultrasound-guided injection is suitable for small joints, such as wrist. For proper and safe use and administration of this technique the collaboration of a trained and experienced radiologist is critical to successful treatment.

La radiosinovectomía es una forma local de radioterapia utilizada como tratamiento de segunda línea en el manejo de artropatías inflamatorias y no inflamatorias con respuesta insatisfactoria a la terapia sistémica o local con corticoesteroides. Tiene una eficacia similar a la sinovectomía quirúrgica, con las ventajas de ser un tratamiento de menor costo, menos cruento y con menor tiempo de convalecencia. Su eficacia es mayor en artropatías inflamatorias caracterizadas por sinovitis, como la artritis reumatoide y artritis crónica juvenil, con compromiso mono u oligoarticular y en articulaciones de extremidades superiores. Existen múltiples isótopos que se pueden utilizar en suspensiones coloidales, siendo el sulfuro coloidal de renio-186 el utilizado para la articulación radiocarpiana. Una técnica de administración adecuada es fundamental para el éxito del tratamiento, siendo la inyección con guía ultrasonográfica adecuada para articulaciones de volumen pequeño, instancia en la que la colaboración del médico radiólogo entrenado es fundamental.

Preparo do 99mTc - DTPA para estudos de cintilografia renal / 99mTc DTPA for renal scintilography studies

O objetivo deste trabalho foi preparar, em condiçöes adequadas, o fármaco (DTPA) marcado com isótopo radioativo para estudos de cinrilografia renal. Além de avaliar a funçäo renal, este fármaco permite diagnosticar, precocemente, alteraçöes que indicam rejeiçäo de tecido, em casos de transplante de rins. Inicialmente, foram realizados experimentos com camundongos para investigar a distribuiçäo biológica do radiofármaco. Os resultados mostraram que, alguns minutos após a administraçäo, os rins apresentavam uma captaçäo de radioatividade. Estes dados e os resultados dos testes de esterilidade, apirogenicidade e pureza radioquímica confirmaram a qualidade do radiofármaco, permitindo o seu emprego em cintilografias de pacientes com comprometimento renal