Utility of 18F-FDG-PET/CT in patients suspected of paraneoplastic neurological syndrome: importance of risk classification

Purpose. To assess the diagnostic impact of 18F-FDG-PET/CT in patients suspected of paraneoplastic neurological syndrome (PNS) based on our own pre-test risk classification (PRC). Methods. A multicenter retrospective longitudinal study was conducted from 2006 to 2014. We designed a seven-point scoring system using the clinical syndrome characteristics [classical (CS) and non-classical syndromes (NCS)] and its location (central, peripheral, in the neuromuscular junction or combined), onconeural antibodies and tumor markers. Patients were classified as low (score 0-2), intermediate (3-4) and high (5-7) pre-test risk of PNS. FDG-PET/CT was classified as negative or positive. Final diagnosis according Graus’ criteria (definite, possible or no PNS) was established. Relations between clinical and metabolic variables with the final diagnosis were studied. Results. 73 patients were included, with a follow-up time of 33 months. Eleven (15 %) patients were finally diagnosed with neoplasm (8 invasive cancers). Ultimately, 13 (18 %) and 24 (33 %) subjects were diagnosed as definite or possible PNS. All the patients with final diagnosis of neoplasm had a CS (p = 0.005). PET/CT was helpful to diagnose 6/8 (75 %) invasive cancers. PET/CT findings were associated with the final diagnosis of neoplasm (p = 0.003) and the diagnosis of PNS attending to Graus’ criteria (p = 0.019). PRC showed significant association with the final diagnosis of neoplasm and PET/CT results. A majority of patients (10/11) diagnosed of neoplasm had intermediate/high-risk. Conclusions. Our PRC seems to be a valid tool to select candidates for PET/CT imaging in this setting. PET/CT detected malignancy in a significant proportion of patients with invasive cancer (AU)

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Basal 18F-FDG PET/CT in follicular lymphoma: a comparison of metabolic and clinical variables in the prognostic assessment / Valor de la 18F-FDG PET/TC basal en el linfoma folicular: comparación de las variables metabólicas y clínicas en la valoración pronóstica

Aim. To analyze the relationship of clinical variables related to prognosis and tumor burden, with metabolic variables obtained in the staging 18F-FDG PET/CT, and their value in the prognosis in follicular lymphoma (FL). Methods. 82 patients with FL, a 18F-FDG PET/CT at diagnosis and a follow-up for a minimum of 12 months, were retrospectively enrolled in the present study. Clinical variables (Tumor grade, Follicular Lymphoma International Prognostic Index (FLIPI) and Tumor burden) were evaluated. Metabolic variables such as SUVmax in the highest hypermetabolic lesion, extralymphatic locations, number of involved lymph node locations, bone marrow (BM) involvement, PET stage and diameter of the biggest hypermetabolic lesion, were analyzed in order to establish a PET score and classify the studies in low, intermediate and high metabolic risk. Clinical and metabolic variables (included metabolic risk) were compared. The relation among all variables and disease-free survival (DFS) was studied. Results. The 28% of patients had a high-grade tumor. The 30.5% had FLIPI risk low, 29.3% intermediate y 40.2% high. The 42.7% presented a high tumor burden. The PET/CT was positive in 94% of patients. The tumor grade did not show significant relation with metabolic variable. FLIPI risk and tumor burden showed statistical relations with the SUV max and the PET score (p<0.008 and p=0.003 respectively). With respect to DFS, significant differences were detected for the PET stage and FLIPI risk (p=0.015 and p=0.047 respectively). FLIPI risk was the only significant predictor in Cox regression analysis, with a Hazard Ratio of 5.13 between high risk and low risk. Conclusion. The present research highlights the significant relation between metabolic variables obtained with FDG PET/CT and clinical variables although their goal as an independent factor of prognosis was not demonstrated in the present work (AU)

Objetivo. Analizar la relación entre las variables clínicas relativas al pronóstico y la carga tumoral y las variables obtenidas en la 18F-FDG PET/TC de estadificación, así como su valor pronóstico para el linfoma folicular (LF). Métodos. Se realizó un estudio retrospectivo de 82 pacientes con LF, 18F-FDG PET/TC en el momento del diagnóstico y seguimiento mínimo de 12 meses. Se evaluaron las variables clínicas (grado tumoral, Índice pronóstico internacional para el linfoma folicular (FLIPI) y carga tumoral). Se analizaron las variables metabólicas tales como SUVmax en las lesiones más hipermetabólicas, localizaciones extralinfáticas, número de localizaciones ganglionares afectas, afectación de la médula ósea, estadio PET y diámetro de la lesión hipermetabólica de mayor tamaño, a fin de establecer una puntuación PET y clasificar los estudios en riesgo bajo, medio y elevado. Se compararon las variables clínicas y metabólicas (incluyendo el riesgo metabólico) y se estudió la relación entre todas las variables y la supervivencia libre de enfermedad (SLE). Resultados. El 28% de los pacientes tenían un tumor de alto grado. El 30,5% tenía un riesgo bajo de FLIPI, el 29,3% un grado intermedio y el 40,2% un riesgo elevado. El 42,7% presentó una elevada carga tumoral. La PET/TC fue positiva en el 94% de los pacientes. El grado del tumor no reflejó una relación significativa con la variable metabólica. El riesgo de FLIPI y la carga tumoral guardaron relaciones estadísticas con SUVmax y la puntuación PET (p<0,008 y p=0,003, respectivamente). Con respecto a la SLE, se detectaron diferencias significativas para el estadio PET y el riesgo FLIPI (p=0,015 y p=0,047, respectivamente). El riesgo FLIPI fue el único factor predictivo significativo en el análisis de regresión, con un cociente de riesgo instantáneo (HR) de 5,13 entre alto y bajo riesgo. Conclusión. La presente investigación resalta la considerable relación entre las variables metabólicas obtenidas con FDG PET/TC y las variables clínicas, aunque su objetivo como factor independiente de pronóstico no ha sido demostrado en el presente estudio (AU)

Glycolytic activity in breast cancer using 18F-FDG PET/CT as prognostic predictor: A molecular phenotype approach / Actividad glicolítica en el cancer de mama mediante 18F-FDG PET/TC como predictor pronóstico: aproximación del fenotipo molecular

Aim. To explore the relationship between basal 18F-FDG uptake in breast tumors and survival in patients with breast cancer (BC) using a molecular phenotype approach. Material and Methods. This prospective and multicentre study included 193 women diagnosed with BC. All patients underwent an 18F-FDG PET/CT prior to treatment. Maximum standardized uptake value (SUVmax) in tumor (T), lymph nodes (N), and the N/T index was obtained in all the cases. Metabolic stage was established. As regards biological prognostic parameters, tumors were classified into molecular sub-types and risk categories. Overall survival (OS) and disease free survival (DFS) were obtained. An analysis was performed on the relationship between semi-quantitative metabolic parameters with molecular phenotypes and risk categories. The effect of molecular sub-type and risk categories in prognosis was analyzed using Kaplan-Meier and univariate and multivariate tests. Results. Statistical differences were found in both SUVT and SUVN, according to the molecular sub-types and risk classifications, with higher semi-quantitative values in more biologically aggressive tumors. No statistical differences were observed with respect to the N/T index. Kaplan–Meier analysis revealed that risk categories were significantly related to DFS and OS. In the multivariate analysis, metabolic stage and risk phenotype showed a significant association with DFS. Conclusion. High-risk phenotype category showed a worst prognosis with respect to the other categories with higher SUVmax in primary tumor and lymph nodes (AU)

Objetivo. Analizar la relación entre la captación basal de 18F-FDG en tumores mamarios y la supervivencia en pacientes con cancer de mama (CM) bajo la aproximación del fenotipo molecular. Material y métodos. Este estudio prospectivo y multicentrico incluyó 193 mujeres diagnosticadas de CM. Todas las pacientes fueron sometidas a una 18F-FDG PET/TC previa al tratamiento. Se obtuvo el SUVmax en el tumor (T), ganglios linfáticos (N) así como el índice N/T en todos los casos. Además se determinó el estadio metabólico. Atendiendo a los factores biológicos pronósticos, los tumores fueron clasificados en subtipos moleculares y categorias de riesgo. Se obtuvo tanto la supervivencia global (SG) como la supervivencia libre de enfermedad (SLE). Se estudió la relación entre los parámetros metabólicos semicuantitativos con los fenotipos moleculares y las categorías de riesgo. Se analizó el efecto del subtipo molecular y las categorías de riesgo en el pronóstico mediante análisis de Kaplan–Meier y test uni y multivariantes. Resultados. Se encontraron diferencias estadísticamente significativas en tanto el SUVT como el SUVN, deacuerdo a los fenotipos moleculares y las categorías de riesgo, con valores mayores en los tumores biológicamente más agresivos. No se observaron diferencias con respecto al índice N/T. El análisis de Kaplan–Meier reveló que las categorías de riesgo se relacionaron de forma significativa con la SG y SLE. En el análisis multivariante, el estadio metabólico y la categoría de riesgo mostraron asociación significativa con la SLE. Conclusion. La categoría de alto riesgo manifestó un peor pronóstico con respecto a las otras categorías, con mayores valores de SUVmax tanto en el tumor primario como en ganglios linfáticos (AU)