J.R. Rodríguez

Pacientes tratados por carcinoma diferenciado de tiroides con rastreos de 131I negativos y niveles de tiroglobulina elevada. Una evolución posible

Resumen Objetivo Constatar la existencia de pacientes con carcinoma diferenciado de tiroides (CDT) tratados que en el seguimiento presentan rastreos negativos con tiroglobulina (Tg) elevada y evolucionan hacia la normalizacion sin otras actuaciones terapeuticas. Material y metodos Revision retrospectiva de los examenes periodicos de 725 pacientes con CDT, analizando los niveles de Tg serica determinados con IRMA anualmente en tratamiento hormonal y cada 1-5 anos en ausencia de tratamiento hormonal, previo a rastreos con 131 I. Seguimiento minimo de 2 anos. Se seleccionaron y se analizaron las caracteristicas de aquellos que presentaron en su evolucion niveles elevados de Tg (> 3 ng/ml), rastreos negativos y otras pruebas de imagen negativas en los que se normalizo la cifra de Tg sin tratamiento medico-quirurgico especifico (grupo I), y de aquellos en los que no se normalizo la cifra de Tg (grupo II). Resultados Se encontraron 130 pacientes (17,93 %) con niveles elevados de Tg y rastreos negativos. Grupo I: 31 pacientes (4,28 %), 11 hombres y 20 mujeres; edad media en el momento del diagnostico de 33,4 anos (rango: 5-60 anos); seguimiento medio: 12,4 anos (± 7,4). Histologia: 27 tumores papilares, 4 foliculares. Dosis media de ablacion 3,260 GBq (88,1 mCi); dosis total media de 131 I 6,850 GBq (185,13 mCi). Normalizacion de la Tg en una media de 8,2 anos. Grupo II: 99 pacientes (13,65 %), 27 hombres y 72 mujeres; edad media de 40,4 anos (rango 7-76); seguimiento medio: 9,8 anos (rango 2-28 anos). Histologia: 86 tumores papilares y 13 tumores foliculares. Dosis media de ablacion de 3,266 GBq (88,28 mCi) y dosis total media de 9,363 GBq (253,06 mCi). Dos de los pacientes del grupo I presentaron fluordesoxiglucosa-F 18 (PET-FDG) negativo. Se detectaron 13 pacientes en los que se constato un descenso progresivo de los niveles de Tg sin llegar a la normalizacion con PET-FDG negativo. Conclusiones En pacientes con CDT irradiado, es posible la normalizacion diferida de los niveles de la Tg. Los tratamientos empiricos no pueden ser considerados como unico factor que contribuye a este resultado.

Patients treated for differentiated thyroid cancer with negative 131I whole-body scanning and elevated thyroglobulin levels. A possible course

Abstract Objective To verify the existence of patients with treated differentiated thyroid cancer (DTC) with negative 131 I whole-body scanning (WBS) and high serum thyroglobulin (Tg) in the follow-up who evolve towards normalization without other therapy interventions. Material and methods Retrospective revision of the periodic examinations established in the protocol for patients with DTC, analyzing the levels of Tg found with IRMA annually in those with hormonal treatment and every 1-5 years in absence of previous hormonal treatment to WBS. Minimum surveillance of 2 years. Those who had elevated levels of Tg and WBS and other negative imaging tests in their course were selected. The characteristics of the patients selected were analysed in those whose Tg levels evolved to normalization without specific medical or surgical treatment (Group I) and those who did not reach normalization of Tg (Group II). Results A total of 130 patients (17.93 %) with high levels of Tg and negative WBS were detected. Group I: 31 patients (4.28 %), 11 men and 20 women; average age at the moment of the diagnosis of 33.4 years (rank: 5-60); average surveillance: 12.4 years (±7.4). Histology: 27 papillary and 4 follicular carcinoma. Average ablation dose: 32.60 GBq (88.1 mCi); average total 131 I dose: 68.50 GBq (185.13 mCi). Tg normalization average time: 8.2 years. Group II: 99 patients (13.65 %), 27 men and 72 women. Average age of 40.4 years (rank: 7-76). Average surveillance: 9.8 years. Histology: 86 papillary and 13 follicular carcinoma. Average ablation dose: 32.66 GBq (88.28 mCi); average total 131 I dose: 93.63 GBq (253.06 mCi). Two of the patients in group I had negative 18 F fluoro-desoxyglucose (FDG-PET). There were 13 patients in whom progressive reduction of the levels of Tg without reaching normalization with negative FDG-PET was detected. Conclusions In patients with radiated DTC, deferred normalization of the levels of the serum Tg is possible. Empirical treatments cannot be considered the only factor that contributes to this result, which can occur without the administration of high-doses of 131 I.

Uso de la PET-18F-FDG en pacientes con sospecha de recurrencia de cáncer diferenciado de tiroides por anticuerpos anti-tiroglobulina elevados y rastreo 131I negativo

AIM To evaluate the utility of (18F)FDG-PET for patients diagnosed of differentiated thyroid carcinoma who present risk of disease and invaluable levels of thyroglobulin (Tg) by the presence of antibodies antithyroglobulin (AbTg). MATERIAL AND METHODS Retrospective study of 7 women of 40 years old and histological diagnosis of differentiated thyroid cancer (7 papillary tumours) that were sent to our department for the accomplishment of(18F)FDG-PET study because of suspicion of disease, due to ¹³¹I negative and high levels of AbTg, between the year 2002 and 2007. 11 PET scans were obtained after the intravenous injection of 370-434 MBq of (18F)FDG in normoglycemia conditions and previous administration of muscle relaxant, hydration and diuretic. The results of (18F)FDG-PET scans were confirmed by pathologic examination or clinical outcome and radiographic examination for more than 24 months. RESULTS The prevalence of recurrence in our population was 57.14%. All patients presented levels of Tg lower than 3 ng/dl and AbTg superior to 200 UI/ml. Three patients had precedent thyroiditis. Out of 11 scans performed 3 of them were negative and 8 cases were found positive. It ruled out the existence of disease in three patients and localized the presence of recurrence in 4 patients. CONCLUSION (18F)FDG-PET CONCLUSION: 18F-FDG-PET is a useful diagnostic tool for the detection of recurrence as well as to rule out the existence of disease with a high accuracy, in patients with differentiated thyroid carcinoma with ¹³¹I whole body scan negative but with pathological elevation of antithyroglobulin antibodies.

La TSH humana recombinante en el seguimiento de pacientes con cáncer diferenciado de tiroides

Resumen Objetivo Estimar el valor del uso de TSH humana recombinante (rhTSH), para el rastreo y tratamiento con I131 en pacientes con CDT avanzado, en los que se desaconseja la interrupcion de toma exogena de hormonas tiroideas. Material y metodos Se realizan 7 rastreos y 4 tratamientos con I131, en cinco hombres y una mujer, edad de 39 a 79 anos. 5 con carcinoma papilar de tiroides y 1 con carcinoma folicular. Pauta de administracion de rhTSH: dos inyecciones intramusculares de 0,9 mg/ml, separadas 24 horas, a las 24 horas de la segunda inyeccion se determina en suero TSH, Tg y AbTg y se administra dosis trazadora de I131 (2 mCi en rastreos postcirugia y 5 mCi en pacientes ya tratados con I131); realizando a las 54 horas en todos los pacientes, y a las 72 horas en caso de duda diagnostica, rastreo de cuerpo completo e imagenes estaticas de areas de interes, en una gammacamara de un detector, con colimador de alta energia. Resultados 4 rastreos positivos (+) y 2 negativos (–). Hubo 1 rastreo positivo que no recibio tratamiento por situacion clinica grave. En los 6 pacientes se elevo eficazmente la TSH, la Tg lo hizo en 4. En los 2 restantes la menor produccion a la esperada de Tg tras el estimulo con rhTSH se explica por desdiferenciacion del tumor y por disminucion de la masa tumoral tras intervencion quirurgica. Conclusiones La rhTSH eleva eficazmente la TSH, permitiendo el rastreo y/o el tratamiento con I131. Es bien tolerada y no presenta efectos adversos significativos. Evita las molestias de la situacion de hipotiroidismo en pacientes de riesgo, manteniendo su calidad de vida. PALABRAS CLAVE: rhTSH. Carcinoma diferenciado de tiroides. Tiroglobulina serica. Rastreo con yodo radiactivo.

Metástasis óseas de tumor primario desconocido. Detección mediante PET-FDG de dos tumores sincrónicos

A 60-year-old woman presented with noncardiac chest pain over months and negative laboratory findings. Conventional imaging methods and bone scintigraphy detected bone lesions suggesting metastatic disease from an unknown primary tumor. An 18FDG-PET scan performed to orient the search for the primary tumor found focal lesions suggesting lymphoma and identified a focal thyroid lesion and a cervical lymph node accessible for biopsy. The biopsy of this lymph node incidentally detected a papillary differentiated thyroid cancer (DTC), since the existence of a non-Hodgkins lymphoma was confirmed after a new biopsy. After confirming the presence of a lymphoma, 18FDG-PET enabled the initial staging of the tumor, the evaluation of the response to treatment, and follow-up for detection of recurrence. On the other hand, 18FDG-PET incidentally detected a DTC.Resumen Paciente mujer de 60 anos con dolor toracico de caracteristicas mecanicas de meses de evolucion y determinaciones analiticas dentro de la normalidad. Los estudios morfologicos y la gammagrafia osea detectaron lesiones oseas sugestivas de afectacion metastasica de un tumor de origen desconocido, por lo que se solicito una exploracion con tomografia por emision de positrones con 2- 18 F-fluoruro-2-deoxi- D-glucosa (PET-FDG) con el objetivo de orientar la busqueda del tumor primario. El estudio se informo como lesiones hipermetabolicas sugestivas de linfoma, mencionando la presencia de una lesion tiroidea hipermetabolica y de una adenopatia cervical accesible para la toma de biopsia. Dicha adenopatia detecto de forma incidental un cancer diferenciado de tiroides (CDT) papilar, ya que posteriormente se confirmo la existencia de un linfoma no-Hodgkin tras la toma de una nueva biopsia. La PET-FDG, tras confirmar la existencia de un linfoma, permitio su estadificacion inicial, asi como valorar la respuesta al tratamiento y realizar su seguimiento. Por otro lado, detecto de forma incidental la existencia de un CDT.

Use of 18FFDG-PET in patients with suspicion of recurrent differentiated thyroid cancer by elevated antithyroglobulin antibodies levels and negative 131I scan

Abstract Aim To evaluate the utility of 18F FDG-PET for patients diagnosed of differentiated thyroid carcinoma who present risk of disease and invaluable levels of thyroglobulin (Tg) by the presence of antibodies antithyroglobulin (AbTg). Material and methods Retrospective study of 7 women of 40 years old and histological diagnosis of differentiated thyroid cancer (7 papillary tumours) that were sent to our department for the accomplishment of 18F FDG-PET study because of suspicion of disease, due to 131 I negative and high levels of AbTg, between the year 2002 and 2007. 11 PET scans were obtained after the intravenous injection of 370–434 MBq of 18F FDG in normoglycemia conditions and previous administration of muscle relaxant, hydration and diuretic. The results of 18F FDG-PET scans were confirmed by pathologic examination or clinical outcome and radiographic examination for more than 24 months. Results The prevalence of recurrence in our population was 57.14%. All patients presented levels of Tg lower than 3 ng/dl and AbTg superior to 200 UI/ml. Three patients had precedent thyroiditis. Out of 11 scans performed 3 of them were negative and 8 cases were found positive. It ruled out the existence of disease in three patients and localized the presence of recurrence in 4 patients. Conclusion 18F-FDG-PET is a useful diagnostic tool for the detection of recurrence as well as to rule out the existence of disease with a high accuracy, in patients with differentiated thyroid carcinoma with 131 I whole body scan negative but with pathological elevation of antithyroglobulin antibodies.

Validation of the renogram with immediate diuretic stimulus

Abstract Objective The aim of this study is to determine the diagnostic reliability of the renogram with diuretic stimulus simultaneously at the administration of the dose, comparing two groups of 59 patients each one (F0 and F+10), to select patients for surgery. Material and Methods This is a retrospective study including two groups of 59 patients in whom the diuretic renogram was carried out by stimulus (furosemide), due to suspicion of ureteropelvic or vesicoureteral obstruction, using 99m Tc-Mercaptoacetylglicine. In the first one, the study was conducted applying the diuretic stimulus 600 seconds after the administration of the dose of the radiotracer (F+10). In the second one, it was carried out simultaneously to the administration (F0). For the interpretation, visual analysis, the parameters of the curves and the percentage of elimination after modification by the severity and micturition were evaluated. Statistical analysis of the information was made. Results The F+10 renogram shows a sensitivity of 96.7 %, specificity of 96.1 %, positive predictive value of 90.6 %, and a negative predictive value of 98.6 %. The F0 renogram shows a sensitivity of 95.2 %, specificity of 98.9 %, positive predictive value of 95.2 %, and a negative predictive value of 98.9 %. Conclusion The performance of the renogram by means of the administration of diuretic stimulus at the same time as the administration of the radiotracer is a useful and comfortable method in paediatric patients, and does not mean a significant loss in the efficacy parameters of the test in the selection of patients for surgery.