Aplicación clínica de la [18F]FDG PET/TC en el linfoma folicular / Clinical application of [18F]FDG PET/CT in follicular lymphoma

El objetivo de este trabajo fue revisar el papel de la [18F]FDG PET/TC en el linfoma folicular (LF). Tras confirmarse que a pesar de su carácter indolente este tipo de linfoma habitualmente muestra avidez por el radiotrazador, la [18F]FDG PET/TC fue cobrando una importancia progresivamente mayor hasta ser considerada como la técnica de elección para su estadificación, re-estadificación y valoración de respuesta al tratamiento. Múltiples estudios han demostrado el impacto que supone en el manejo de estos pacientes (puede cambiar el estadio de la enfermedad en una proporción significativa de casos y condicionar modificaciones en el tratamiento), su superioridad respecto a la TC (principalmente por la capacidad para distinguir tejido tumoral viable de tejido fibrótico residual) y su valor pronóstico. Esto último se atribuyó inicialmente de forma exclusiva al grado de respuesta metabólica alcanzado tras el tratamiento, que ha probado ser un factor predictivo fuerte e independiente de supervivencia libre de progresión (SLP) y supervivencia global (SG), de modo que una [18F]FDG PET/TC negativa podría considerarse una garantía para los pacientes con LF con elevada carga tumoral. No obstante, la obtención de parámetros metabólicos semicuantitativos como el volumen metabólico tumoral o la glucólisis total de la lesión podría también aportar información a este respecto y ayudarnos potencialmente a identificar a los pacientes de mal pronóstico antes del inicio del tratamiento, de forma que se pueda adecuar el manejo y seguimiento al riesgo del paciente (AU)

The objective of the present paper was to review the clinical application of [18F]FDG PET/CT in follicular lymphoma (FL). Once it was clear that, despite it's characterized as indolent, this type of lymphoma usually shows a high [18F]FDG avidity, PET/CT became more important and it's now considered the standard technique in staging, re-staging and response evaluation. Many studies have shown its impact on the management of patients (as it can change the stage in a significant proportion of cases and lead to treatment modifications), its superiority over CT (mainly because it's able to distinguish fibrosis in residual masses from viable tumor) and its prognostic value. The latter was initially associated only to the degree of metabolic response, which has proved to be a strong and independent predictive factor in terms of disease-free survival (DFS) and overall survival (OS). Thus, a negative PET/CT scan could be considered a guarantee in high-tumor-burden follicular lymphoma patients. However, semiquantitative parameters such as metabolic tumor volume or total lesion glycolysis, may also provide useful information and help us to identify patients with poor prognosis, guiding a risk-adjusted management and follow-up (AU)

Clinical application of [18F]FDG PET/CT in follicular lymphoma.

The objective of the present paper was to review the clinical application of [18F]FDG PET/CT in follicular lymphoma (FL). Once it was clear that, despite it is characterized as indolent, this type of lymphoma usually shows a high [18F]FDG avidity, PET/CT became more important and it's now considered the standard technique in staging, re-staging and response evaluation. Many studies have shown its impact on the management of patients (as it can change the stage in a significant proportion of cases and lead to treatment modifications), its superiority over CT (mainly because it's able to distinguish fibrosis in residual masses from viable tumor) and its prognostic value. The latter was initially associated only to the degree of metabolic response, which has proved to be a strong and independent predictive factor in terms of disease-free survival (DFS) and overall survival (OS). Thus, a negative PET/CT scan could be considered a guarantee in high-tumor-burden follicular lymphoma patients. However, semiquantitative parameters such as metabolic tumor volume or total lesion glycolysis, may also provide useful information and help us to identify patients with poor prognosis, guiding a risk-adjusted management and follow-up.

Tumor miofibroblástico inflamatorio. Hallazgos en la PET/TC con 18F-FDG / Inflammatory myofibroblastic tumor.18F-FDG PET/CT findings

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Utility of low dose (18)F-FDG PET-CT in patients with suspected colorectal carcinoma recurrence in conventional diagnostic methods.

OBJECTIVE: To evaluate the efficacy of (18)F-FDG PET-CT in the diagnosis of recurrence of colorectal cancer (CRC) in patients with elevated values of carcinoembryonic antigen (CEA) and/or signs of recurrence in the multidetector CT (MDCT), and to demonstrate that good results can be obtained applying the ALARA principles. MATERIAL AND METHODS: A retrospective study of 54 patients with suspected CRC, who underwent an (18)F-FDG PET-CT, administering a mean dose of 222 MBq (6 mCi) of (18)F-FDG, from 07/2007 to 01/2011 was carried out. Seven patients were excluded, thus studying 47 (27 males, 20 females, mean age 63 years). Recurrence was confirmed by histopathology study in 14 cases and by clinical evolution in 33. The patients were divided into 4 groups. A: patients with elevation of CEA and suspected recurrence in the MDCT. B: elevation of CEA, without suspicious lesions in the MDCT. C: normal levels of CEA and positive MDCT. D: normal levels of CEA and uncertain MDCT. RESULTS: We found sensitivity, specificity, PPV, NPV and overall accuracy of 91%, 69%, 89%, 75% and 85% respectively. For group A, we found 100% sensitivity, in group B, 75% sensitivity with 100% specificity%, for C, sensitivity was 89% with 71% specificity. Finally, in group D, sensitivity was 100% and specificity 60%, respectively. CONCLUSION: Applying a low dose, the (18)F-FDG PET-CT has high diagnostic performance in patients with suspicion of CRC, approaching in a higher grade the ALARA criteria.

Utilidad de la PET-TC con baja dosis de 18F-FDG en pacientes con sospecha de recurrencia de carcinoma colorrectal en métodos diagnósticos convencionales / Utility of low dose 18F-FDG PET-CT in patients with suspected colorectal carcinoma recurrence in conventional diagnostic methods

Propósito. Evaluar la eficacia de la 18F-FDG PET-TC en el diagnóstico de la recurrencia del carcinoma colorrectal (RCCR), en pacientes con valores de CEA elevados y/o signos de recurrencia en la TC multidetector (TCMD), así como demostrar que se pueden obtener buenos resultados aplicando los principios ALARA. Materiales y métodos. Estudio retrospectivo de 54 pacientes con sospecha de RCCR, a los cuales se les realizó una 18F-FDG PET-TC, administrando una dosis media de 222 MBq (6 mCi) de 18F-FDG, desde 07/2007 hasta 01/2011. Excluimos 7 pacientes, estudiando a 47 (27 varones, 20 mujeres, edad media 63 años). La recurrencia se confirmó por histopatología en 14 casos y por evolución clínica en 33. Los pacientes se dividieron en 4 grupos. A: pacientes con elevación del CEA y sospecha de recidiva en la TCMD. B: elevación del CEA, sin lesiones sospechosas en la TCMD. C: niveles de CEA normales y la TCMD positiva. D: niveles de CEA normales y la TCMD dudosa. Resultados. : Encontramos una sensibilidad, especificidad, VPP, VPN y exactitud global de 91, 69, 89, 75 y 85, respectivamente. Para el grupo A encontramos una sensibilidad del 100%, en el B una sensibilidad del 75% y especificidad del 100%, para el C una sensibilidad del 89% y especificidad del 71%, finalmente para el D una sensibilidad y especificidad del 100 y 60%, respectivamente. Conclusión. Aplicando una baja dosis, la 18F-FDG PET-TC tiene un alto rendimiento diagnóstico en pacientes con sospecha de RCCR, acercándose en mayor grado a los criterios ALARA(AU)

Objective. To evaluate the efficacy of 18F-FDG PET-CT in the diagnosis of recurrence of colorectal cancer (CRC) in patients with elevated values of carcinoembryonic antigen (CEA) and/or signs of recurrence in the multidetector CT (MDCT), and to demonstrate that good results can be obtained applying the ALARA principles. Material and methods. A retrospective study of 54 patients with suspected CRC, who underwent an 18F-FDG PET-CT, administering a mean dose of 222 MBq (6 mCi) of 18F-FDG, from 07/2007 to 01/2011 was carried out. Seven patients were excluded, thus studying 47 (27 males, 20 females, mean age 63 years). Recurrence was confirmed by histopathology study in 14 cases and by clinical evolution in 33. The patients were divided into 4 groups. A: patients with elevation of CEA and suspected recurrence in the MDCT. B: elevation of CEA, without suspicious lesions in the MDCT. C: normal levels of CEA and positive MDCT. D: normal levels of CEA and uncertain MDCT. Results. We found sensitivity, specificity, PPV, NPV and overall accuracy of 91%, 69%, 89%, 75% and 85% respectively. For group A, we found 100% sensitivity, in group B, 75% sensitivity with 100% specificity%, for C, sensitivity was 89% with 71% specificity. Finally, in group D, sensitivity was 100% and specificity 60%, respectively. Conclusion. Applying a low dose, the 18F-FDG PET-CT has high diagnostic performance in patients with suspicion of CRC, approaching in a higher grade the ALARA criteria(AU)

Captación de 18F-FDG en timo tras terapia ablativa de restos tiroideos con 131I / Thymic uptake of 18FFDG following radioiodine ablation therapy

Presentamos el caso de una mujer de 47 años con antecedente de linfoma no Hodgkin. En el transcurso de su enfermedad se le realizan varias PET/TAC con 18F-FDG que muestran varios hallazgos incidentales significativos. En primer lugar, encontramos incidentalmente un nódulo hipermetabólico en el lóbulo tiroideo izquierdo, cuyo diagnóstico definitivo fue de carcinoma papilar. En segundo lugar, se observó actividad metabólica en timo secundaria al tratamiento ablativo de restos tiroideos con radioyodo, que desapareció en los estudios posteriores. Se han publicado múltiples artículos acerca de la hiperplasia tímica tras quimioterapia, pero sólo hemos encontrado un caso descrito de captación de 18F-FDG tras radioyodo. Por otra parte, este caso es de interés ya que apoya la conveniencia de estudiar los nódulos tiroideos hipermetabólicos detectados incidentalmente en la PET/TAC(AU)

We report the case of a 47 year-old woman with a history of non-Hodgkin's lymphoma. During the course of her disease, we performed various 18FFDG PET/CT that identified several significant incidental findings. First, we incidentally identified a hypermetabolic nodule in the left thyroid lobe, whose final diagnosis was differentiated thyroid carcinoma. Second, metabolic activity was visualized in the thymus secondary to ablative treatment with radioiodine. This uptake disappeared in subsequent studies. Several papers have reported thymic rebound following chemotherapy but we have found only one case report of 18FFDG uptake after radioiodine treatment. On the other hand, this case is of interest because it supports the benefit of studying the hypermetabolic thyroid nodules incidentally detected on the PET/CT performed for other reasons(AU)

[Thymic uptake of 18FFDG following radioiodine ablation therapy]. / Captación de 18F-FDG en timo tras terapia ablativa de restos tiroideos con 131I.

We report the case of a 47 year-old woman with a history of non-Hodgkin's lymphoma. During the course of her disease, we performed various (18F)FDG PET/CT that identified several significant incidental findings. First, we incidentally identified a hypermetabolic nodule in the left thyroid lobe, whose final diagnosis was differentiated thyroid carcinoma. Second, metabolic activity was visualized in the thymus secondary to ablative treatment with radioiodine. This uptake disappeared in subsequent studies. Several papers have reported thymic rebound following chemotherapy but we have found only one case report of (18F)FDG uptake after radioiodine treatment. On the other hand, this case is of interest because it supports the benefit of studying the hypermetabolic thyroid nodules incidentally detected on the PET/CT performed for other reasons.

[Diagnostic value of cardiac 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy in Lewy body disorders]. / Valor diagnóstico de la gammagrafía cardíaca con 123I-metaiodobenzilguanidina en las enfermedades con cuerpos de Lewy.

INTRODUCTION: Lewy body disorders such as Parkinson's disease (PD) and Lewy body dementia (LBD) are associated with cardiac sympathetic denervation, which can be visualized on 123I-MIBG scintigraphy. Our objectives were to study the diagnostic value of this technique in Lewy body disorders and its relationship with PD clinical variables. PATIENTS AND METHODS: We studied 90 patients: 51 with PD, 19 with LBD, 9 with multiple system atrophy (MSA) and 11 controls. Scintigraphy images were qualitatively evaluated and early and delayed heart-to-mediastinum ratios (HMR) were calculated. The main confounding factors (ischemic heart disease, diabetes, hypertension and drugs) were controlled by multivariate linear regression analysis. We investigated correlations between scintigraphy variables and PD variables. RESULTS: The delayed HMR, which showed better discriminative ability was 2.03 +/- 0.32 in controls, 1.37 +/- 0.30 in PD (p<0.001 vs controls), 1.47+/-0.45 in LBD (p=0.001 vs controls) and 1.69+/-0.28 in MSA (p=0.02 vs controls; p=0.004 vs PD). This ratio was influenced by PD/LBD diagnosis (beta= -0.638; p<0.001) and to a lesser degree, by ischemic heart disease (beta= -0.244; p=0.028). Optimal cut-off value between PD/LBD and controls was 1.71 (83% sensitivity and 82% specificity). Within the PD group, those with a family history of PD/LB showed higher delayed HMR values (1.65+/-0.34 vs 1.30+/-0.24 without history; p<0.001) and proportion with normal scintigraphy (56% vs 5%; p=0.001). CONCLUSIONS: Cardiac 123I-MIBG scintigraphy is useful in the diagnosis of Lewy body disorders, although its value in PD is conditioned by having a family history of PD.

Valor diagnóstico de la gammagrafíacardíaca con 123I-metaiodobenzilguanidinaen las enfermedades con cuerpos de Lewy / Diagnostic value of cardiac 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy in Lewy body disorders

Introducción. Enfermedades con cuerpos de Lewy (ECL), como laenfermedad de Parkinson (EP) y la demencia con cuerpos de Lewy(DCL), asocian una denervación simpática cardíaca que puede evidenciarsemediante gammagrafía con 123I-metaiodobenzilguanidina(123I-MIBG). Nuestros objetivos fueron estudiar su valor diagnósticoen las ECL y su relación con variables clínicas de la EP.Pacientes y métodos. Estudiamos 90 pacientes: 51 con EP, 19 conDCL, 9 con atrofia multisistémica (AMS) y 11 controles. Se realizó valoracióncualitativa de la gammagrafía y se calcularon los índices corazón/mediastino (ICM) precoz y tardío. Los principales factores deconfusión (cardiopatía isquémica, diabetes, hipertensión y fármacos)se controlaron mediante regresión lineal multivariante. Efectuamoscorrelaciones entre las variables gammagráficas y del grupo con EP.Resultados. El ICM tardío, con mayor capacidad discriminativa,fue 2,03±0,32 en los controles, 1,37±0,30 en EP (p<0,001 vs controles),1,47±0,45 en DCL (p=0,001 vs controles) y 1,69±0,28 enAMS (p=0,02 vs controles; p=0,004 vs EP). En este índice influía eldiagnóstico de ECL (ß=–0,638; p<0,001) y en menor grado la cardiopatíaisquémica (ß=–0,244; p=0,028). Identificamos el valor 1,71como mejor punto de corte entre ECL y controles (sensibilidad 83%y especificidad 82%). Dentro del grupo con EP, aquellos con antecedentesfamiliares de EP mostraron mayores ICM tardío (1,65±0,34 vs1,30±0,24 sin antecedentes; p<0,001) y proporción de gammagrafíasnormales (56% vs 5%; p=0,001).Conclusiones. La gammagrafía cardíaca con 123I-MIBG es útilen el diagnóstico de ECL, si bien, en la EP su valor está condicionadopor el hecho de tener historia familiar de la enfermedad (AU)

Introduction. Lewy body disorders such as Parkinson’s disease(PD) and Lewy body dementia (LBD) are associated withcardiac sympathetic denervation, which can be visualized on123I-MIBG scintigraphy. Our objectives were to study the diagnosticvalue of this technique in Lewy body disorders and its relationshipwith PD clinical variables.Patients and methods. We studied 90 patients: 51 with PD,19 with LBD, 9 with multiple system atrophy (MSA) and 11 controls.Scintigraphy images were qualitatively evaluated and earlyand delayed heart-to-mediastinum ratios (HMR) were calculated.The main confounding factors (ischemic heart disease, diabetes,hypertension and drugs) were controlled by multivariate linearregression analysis. We investigated correlations between scintigraphyvariables and PD variables.Results. The delayed HMR, which showed better discriminativeability was 2.03 ± 0.32 in controls, 1.37 ± 0.30 in PD(p<0.001 vs controls), 1.47±0.45 in LBD (p=0.001 vs controls) and1.69±0.28 in MSA (p=0.02 vs controls; p=0.004 vs PD). This ratiowas influenced by PD/LBD diagnosis (ß=–0.638; p<0.001)and to a lesser degree, by ischemic heart disease (ß = –0.244;p=0.028). Optimal cut-off value between PD/LBD and controlswas 1.71 (83% sensitivity and 82% specificity). Within the PDgroup, those with a family history of PD/LB showed higher delayedHMR values (1.65±0.34 vs 1.30±0.24 without history; p<0.001)and proportion with normal scintigraphy (56% vs 5%; p=0.001).Conclusions. Cardiac 123I-MIBG scintigraphy is useful in thediagnosis of Lewy body disorders, although its value in PD isconditioned by having a family history of PD (AU)