Análisis visual y semicuantitativo del 6-[18F]FDOPA PET/TC en pacientes con tumores cerebrales ante la sospecha de recurrencia tumoral versus radionecrosis / VAnálisis visual y semicuantitativo del 6-[18F]FDOPA PET/TC en pacientes con tumores cerebrales ante la sospecha de recurrencia tumoral versus radionecrosis

Introducción La tomografía por emisión de positrones (PET) con aminoácidos es una herramienta recomendada por las principales sociedades de neuroimagen, en el diagnóstico diferencial entre radionecrosis (RNC) y recurrencia tumoral (RT) en los tumores cerebrales, sin embargo, su uso en nuestro pais aún es limitado. El objetivo de este trabajo es presentar nuestra experiencia con 6-[18F]FDOPA PET/TC (FDOPA) en tumores cerebrales (primarios y M1), comparando estos resultados con otros publicados. Material y métodos Estudio retrospectivo de 62 pacientes con sospecha de RT: 42 metástasis cerebrales (M1) y 20 primarios, a los que se les realizó una FDOPA. Las imágenes fueron analizadas visual y semicuantitativamente, obteniendo el SUVmax y los ratios SUVmaxlesión/SUVmaxestriado (L/E) y SUVmaxlesión/SUVmaxcortex (L/C). Se analizó la validez diagnóstica de la PET y se calcularon los puntos de corte con mayor rendimiento. Los resultados de la PET se compararon con la evolución clínico-radiológica y/o con la histopatología. Resultados Se identificó RT en el 49% de las M1 y en el 76% de los primarios cerebrales. La interpretación de la FDOPA con mejores resultados fue la conjunta; visual y semicuantitativa, con una sensibilidad y especificidad en los primarios del 94 y 80% y en las M1 del 96 y 72%, respectivamente. Los puntos de corte con mejor rendimiento diagnóstico fueron L/C 1,44 en M1 y L/C 1,55 en primarios. Existen resultados discrepantes con otros publicados. Conclusión La FDOPA PET/TC es una herramienta útil en el diagnóstico diferencial entre RT y RNC en tumores cerebrales. Es necesario una estandarización que contribuya a homogeneizar los resultados de la FDOPA a nivel intercentro (AU)

Introduction Amino acid PET is a tool recommended by the main neuroimaging societies in the differential diagnosis between radionecrosis (RNC) and tumour recurrence (TR) in brain tumours, but its use in our country is still limited. The aim of this work is to present our experience with 6-[18F]FDOPA PET/CT (FDOPA) in brain tumours (primary and M1), comparing these results with other published results. Material and methods Retrospective study of 62 patients with suspected tumour recurrence (TR): 42 brain metastases (M1) and 20 primary, who underwent FDOPA. Images were analysed visually and semi-quantitatively, obtaining SUVmax and SUVmaxlesion/SUVmaxstriatum (L/S) and SUVmaxlesion/SUVmaxcortex (L/C) ratios. The diagnostic validity of PET was analysed and the best performing cut-off points were calculated. PET results were compared with clinical-radiological follow-up and/or histopathology. Results TR was identified in 49% of M1 and 76% of brain primaries. The best performing FDOPA interpretation was visual and semi-quantitative, with a sensitivity and specificity in primaries of 94% and 80% and in M1s of 96% and 72% respectively. The cut-off points with the best diagnostic performance were L/C1.44 in M1 and L/C1.55 in primaries. There are discrepant results with other published results. Conclusion FDOPA PET/CT is a useful tool in the differential diagnosis between recurrence and RNC in brain tumours. It is needed a standardization to contribute to homogenise FDOPA results a inter-centre level (AU)

El papel de la PET/TC con 2-[18F]FDG en la enfermedad de Erdheim-Chester / The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease

Objetivo Analizar la distribución corporal de la enfermedad Erdheim-Chester (ECD) y determinar la utilidad de la 2-[18F]FDG-PET/TC frente a otras técnicas de imagen. Asimismo, evaluar la agresividad y la extensión de la enfermedad según la presencia/ausencia de mutación BRAFV600E. Material y métodos Se revisaron las 2-[18F]FDG-PET/TC de todos los pacientes diagnosticados con ECD entre 2008 y 2021: en total, 19 pacientes. Los territorios afectados se clasificaron como detectables por PET/TC o detectables solamente por otras técnicas de imagen (gammagrafía ósea, TC con contraste yodado o RM). Se realizó análisis descriptivo y correlación de la mutación BRAF con los órganos afectados y SUVmáx mediante la prueba t de Student. Resultados De los 19 pacientes (14 hombres; edad media 60,3años), 11 presentaban la mutación BRAFV600E. Se detectaron un total de 127 territorios (64 órgano-sistemas) afectados utilizando las diferentes modalidades de imagen, de los cuales 112 fueron detectados por la PET/TC y 15 territorios adicionales fueron identificados únicamente por la RM cerebral y cardiaca. La presencia de mutación BRAFV600E se asoció con mayor afectación orgánica (p<0,05), sin diferencias en el SUVmáx (p>0,05). Conclusión La 2-[18F]FDG-PET/TC es una prueba de alto rendimiento diagnóstico en pacientes con ECD, detectando la mayoría de los territorios afectados. La RM fue la única prueba de imagen con hallazgos adicionales en territorios con alta captación fisiológica de 2-[18F]FDG (cerebral y cardíaca). La presencia de mutación del BRAFV600E se correlacionó con mayor extensión de la enfermedad (AU)

Objective To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAFV600E mutation. Materials and methods The 2-[18F]FDG PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test. Results Out of the 19 patients (14 males; mean age 60.3years), 11 had the BRAFV600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAFV600E mutation was associated with greater organ involvement (P<.05) without differences in SUVmax (P>.05). Conclusion 2-[18F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[18F]FDG (cerebral and cardiac). The presence of the BRAFV600E mutation correlated with a higher extent of the disease (AU)

The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease.

OBJECTIVE: To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18 F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAFV600E mutation. MATERIALS AND METHODS: The 2-[18F]FDG-PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test. RESULTS: Out of the 19 patients (14 males; mean age 60.3 years), 11 had the BRAFV600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAFV600E mutation was associated with greater organ involvement (p < 0.05) without differences in SUVmax (p > 0.05). CONCLUSION: 2-[18F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[18F]FDG (cerebral and cardiac). The presence of the BRAFV600E mutation correlated with a higher extent of the disease.

Visual and semi-quantitative analysis of 6-[18F]FDOPA PET/CT in patients with brain tumors and suspected tumor recurrence versus radionecrosis.

INTRODUCTION: Amino acid PET is a tool recommended by the main neuroimaging societies in the differential diagnosis between radionecrosis (RNC) and umour recurrence (TR) in brain tumours, but its use in our country is still limited. The aim of this work is to present our experience with 6-[18F]FDOPA PET/CT (FDOPA) in brain tumours (primary and M1), comparing these results with other published results. MATERIAL AND METHODS: Retrospective study of 62 patients with suspected tumour recurrence (TR): 42 brain metastases (M1) and 20 primary, who underwent FDOPA. Images were analysed visually and semi-quantitatively, obtaining SUVmax and SUVmaxlesion/SUVmaxstriatum (L/S) and SUVmaxlesion/SUVmaxcortex (L/C) ratios. The diagnostic validity of PET was analysed and the best performing cut-off points were calculated. PET results were compared with clinical-radiological follow-up and/or histopathology. RESULTS: TR was identified in 49% of M1 and 76% of brain primaries. The best performing FDOPA interpretation was visual and semi-quantitative, with a sensitivity and specificity in primaries of 94% and 80% and in M1s of 96% and 72% respectively. The cut-off points with the best diagnostic performance were L/C1.44 in M1 and L/C1.55 in primaries. There are discrepant results with other published results. CONCLUSION: FDOPA PET/CT is a useful tool in the differential diagnosis between recurrence and RNC in brain tumours. It is needed a standardization to contribute to homogenise FDOPA results a inter-centre level.

Impact of previous glucocorticoid therapy on diagnostic accuracy of [18F] FDG PET-CT in giant cell arteritis.

OBJECTIVE: To evaluate the impact of prior glucocorticoid (GC) treatment on the diagnostic accuracy of 18F-FDG PET-CT in giant cell arteritis (GCA). METHODS: Retrospective study of a consecutive cohort of 85 patients with proven GCA who received high-dose GC before PET-CT. RESULTS: Thirty-nine patients previously treated with methylprednisolone (MP) boluses, of whom 37% were PET-CT (uptakes grade 3 or 2) positive. The positivity rate was 80% with MP doses of 125 mg, 33% with 250 or 500 mg, and 0% with doses of 1 g.  If we also classify as positive those cases with a grade 1 uptake (with a circumferencial uptake and smooth linear or long segmental pattern, possibly indicative of "apparently inactive" vasculitis), the positivity rate increases to 62% (100%, 50-60%, and 33% for the different MP doses, respectively). In patients with new-onset GCA treated with high-dose oral GC, PET-CT positivity was 54.5% in patients treated for less than two weeks, 38.5% in those treated for 2 to 4 weeks, and 25% in those treated for 4 to 6 weeks (increasing to 91%, 77%, and 50%, respectively, if we include cases with grade 1 uptake and these characteristics). In patients with relapsing/refractory GCA, or who developed GCA having a prior history of PMR, PET-CT positivity reached 54% despite long-term treatment with low-to-moderate doses of GC (68% including cases with a grade 1 uptake). CONCLUSION: A late 18F-FDG PET-CT (beyond the first 10 days of treatment) can also be informative in a considerable percentage of cases.

Diagnosing neuroleukemiosis: is there a role for 18F-FDG-PET/CT? / Diagnosticando la neuroleucemiosis: ¿existe un papel para la PET/TC con 18F-FDG?

An imaging case is presented on a patient referred to our department for an 18F-FDG-PET/CT, as a paraneoplastic syndrome was suspected due to his clinical situation. He had a history of acute myeloid leukemia (AML) treated two years earlier, with sustained complete remission to date. 18F-FDG-PET/CT findings revealed hypermetabolism in almost all nerve roots, suggesting meningeal spread, consistent with the subsequent MRI findings. Cerebrospinal fluid (CSF) findings confirmed a leptomeningeal reactivation of AML. Although not many studies have evaluated the role of 18F-FDG-PET/CT in leukemia, it is a noninvasive tool for detecting extramedullary sites of disease and a good imaging alternative for those patients on whom an MRI cannot be performed (AU)

Presentamos el caso de un paciente remitido a nuestro servicio para la realización de una PET/TC con 18F-FDG por sospecha clínica de un síndrome paraneoplásico Entre sus antecedentes destacaba el de una leucemia mieloide aguda tratada 2 años antes y en remisión completa en los controles sucesivos. La PET/TC con 18F-FDG mostró hipermetabolismo en prácticamente todas las raíces nerviosas, apuntando a enfermedad meníngea diseminada, en concordancia con los hallazgos de la RM realizada posteriormente. El análisis del líquido cefalorraquídeo confirmó una reactivación leptomeníngea de la leucemia mieloide aguda. A pesar de los pocos estudios existentes sobre el papel de la PET/TC con 18F-FDG en la leucemia, es una herramienta no invasiva para localizar recidivas extramedulares de la enfermedad y una buena técnica de imagen alternativa para aquellos pacientes a los que no se les puede realizar una RM (AU)

18F-FDG PET/CT in the detection of a primary radiation-induced metastatic angiosarcoma / 18F-FDG PET/TC en la detección de angiosarcoma primario radioinducido metastásico

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Diagnosing neuroleukemiosis: Is there a role for 18F-FDG-PET/CT?

An imaging case is presented on a patient referred to our department for an 18F-FDG-PET/CT, as a paraneoplastic syndrome was suspected due to his clinical situation. He had a history of acute myeloid leukemia (AML) treated two years earlier, with sustained complete remission to date. 18F-FDG-PET/CT findings revealed hypermetabolism in almost all nerve roots, suggesting meningeal spread, consistent with the subsequent MRI findings. Cerebrospinal fluid (CSF) findings confirmed a leptomeningeal reactivation of AML. Although not many studies have evaluated the role of 18F-FDG-PET/CT in leukemia, it is a noninvasive tool for detecting extramedullary sites of disease and a good imaging alternative for those patients on whom an MRI cannot be performed.

Utilidad de la PET-TC en la valoración de la respuesta precoz al tratamiento en el linfoma B difuso de celula grande. Resultados preliminares / Utility of the PET-CT in the evaluation of early response to treatment in the diffuse large B-cell lymphoma. Preliminary results

Objetivo. Valorar la utilidad de la PET-TC con FDG tras los primeros ciclos de quimioterapia en la predicción de la respuesta al tratamiento en pacientes con linfoma B difuso de célula grande. Metodologia. Se incluyeron 20 pacientes (edad media: 48), 16 en la estadificación inicial y 4 por recidiva. La PET-TC se realizó en tres tiempos: 1) Basal, 2) Tras el primer-tercer ciclo (valoración de respuesta precoz), y 3) Al finalizar el tratamiento (valoración de respuesta final). Los hallazgos de la valoración precoz fueron correlacionados con la valoración final y el seguimiento. La valoración de la respuesta se estableció según la disminución de la captación de las lesiones (SUVmax). En la valoración precoz el indicador de buena respuesta (IBR) fue la reducción del SUVmax > 50% o la desaparición. Al final del tratamiento se determinó la respuesta metabólica completa (RMC) en ausencia de focos. El seguimiento fue superior a los 19 meses, estableciendo progresión/recidiva o sin evidencia de enfermedad (SEE). Resultados. La valoración precoz fue IBR en 16/16 pacientes de estadificación inicial (100%) y en 2/4 de recidiva (50%). Al final del tratamiento, en el primer grupo 14/16 pacientes con IBR consiguieron RMC y 1/16 RMP; 14 continuaron SEE y uno recidivó. En el segundo grupo 2/2 pacientes con IBR consiguieron RMC; uno continuó SEE y otro recidivó. Conclusion. La PET-TC tras los primeros ciclos de quimioterapia es útil para monitorizar el tratamiento debido a su elevado valor predictivo negativo (87,5%), modificando la terapia precozmente en los no respondedores(AU)

Objective. To assess the role of FDG-PET/CT performed after the first cycles of chemotherapy in the prediction of response to treatment in patients with diffuse large B-cell lymphoma. Methods. Twenty patients (mean age: 48 years) were included, 16 initial staging and 4 relapse. All patients underwent PET/CT at 3 times: 1) Baseline, 2) After 1-3 cycles of chemotherapy (early response assessment), and 3) End of treatment (evaluation of final response). Early PET/CT findings were correlated to the end-treatment PET/CT and follow-up. The evaluation of the response was established according to the decrease in uptake of the lesions (SUVmax). In the early assessment, a good response indicator (GRI) was obtained when the lesion disappeared or had more than 50% reduction in SUVmax. At the end of the treatment, a complete metabolic response (CMR) was determined in negative PET scans. Follow-up was superior to 19 months and final outcome was established as progression/relapse or no evidence of disease (NED). Results. At the early treatment evaluation, 16/16 patients of initial staging (100%) and 2/4 of relapse (50%) achieved GRI. At the end of treatment evaluation, 14/16 patients of initial staging with GRI achieved CMR and 1/16 PMR: 14 were alive with NED in the follow-up while 1 relapsed. In the second group, 2/2 patients with GRI achieved CMR (100%): 1 continued with NED in the follow-up and another relapsed. Conclusion. FDG-PET/CT after the first cycles of chemotherapy is useful to monitor treatment due to its high negative predictive value (87.5%), using it to modify treatment early in the non-responders(AU)

Utility of the PET-CT in the evaluation of early response to treatment in the diffuse large B-cell lymphoma. Preliminary results.

OBJECTIVE: To assess the role of FDG-PET/CT performed after the first cycles of chemotherapy in the prediction of response to treatment in patients with diffuse large B-cell lymphoma. METHODS: Twenty patients (mean age: 48 years) were included, 16 initial staging and 4 relapse. All patients underwent PET/CT at 3 times: 1) Baseline, 2) After 1-3 cycles of chemotherapy (early response assessment), and 3) End of treatment (evaluation of final response). Early PET/CT findings were correlated to the end-treatment PET/CT and follow-up. The evaluation of the response was established according to the decrease in uptake of the lesions (SUVmax). In the early assessment, a good response indicator (GRI) was obtained when the lesion disappeared or had more than 50% reduction in SUVmax. At the end of the treatment, a complete metabolic response (CMR) was determined in negative PET scans. Follow-up was superior to 19 months and final outcome was established as progression/relapse or no evidence of disease (NED). RESULTS: At the early treatment evaluation, 16/16 patients of initial staging (100%) and 2/4 of relapse (50%) achieved GRI. At the end of treatment evaluation, 14/16 patients of initial staging with GRI achieved CMR and 1/16 PMR: 14 were alive with NED in the follow-up while 1 relapsed. In the second group, 2/2 patients with GRI achieved CMR (100%): 1 continued with NED in the follow-up and another relapsed. CONCLUSION: FDG-PET/CT after the first cycles of chemotherapy is useful to monitor treatment due to its high negative predictive value (87.5%), using it to modify treatment early in the non-responders.

[Usefulness of ventricular function values obtained using post-stress gated-SPECT in a diabetic population with clinical suspicion of ischaemic heart disease]. / Utilidad de los valores de función ventricular obtenidos mediante gated-SPECT post-estrés en población diabética con sospecha clínica de cardiopatía isquémica.

OBJECTIVE: To assess the clinical usefulness of left ventricular function values obtained using post-stress myocardial perfusion gated-SPECT in diabetic patients with suspected ischaemic heart disease (IHD). MATERIALS AND METHODS: Sixty-one patients with diabetes mellitus (DM), with clinical suspicion of IHD and no previous history of heart disease were studied. Ergometric or pharmacological post-stress myocardial perfusion gated-SPECT was performed on all patients. The relationship between the ejection fraction values and ventricular volumes, and the perfusion study results, final diagnosis, severity of the perfusion defects and the clinical evolution was studied. The mean follow-up time was 14 months. RESULTS; All the ventricular function values independently showed significant differences between the groups with a normal and pathological perfusion study, and between groups with a final diagnosis of IHD and non-IHD. After multivariate logistic regression, the end-diastolic volume (EDV) was the only value which showed a statistical association with the pathological perfusion study, its severity and the final diagnosis of IHD. No statistical association was observed between the ventricular function values and the occurrence of cardiac events. CONCLUSIONS: All the ventricular function values obtained by gated-SPECT added diagnostic information to the post-stress myocardial perfusion study in the diabetic population with suspected IHD; however, only EDV showed a statistical association with the pathological perfusion study, severity of defects and the final diagnosis of IHD.

Utilidad de los valores de función ventricular obtenidos mediante gated-SPECT post-estrés en población diabética con sospecha clínica de cardiopatía isquémica / Usefulness of ventricular function values obtained using post-stress gated-SPECT

Objetivo. Evaluar la utilidad clínica aportada por los valores de función ventricular izquierda obtenidos mediante gated-SPECT (tomografía computarizada por emisión de fotón único) de perfusión miocárdica post-estrés en pacientes diabéticos con sospecha de cardiopatía isquémica (CI). Material y métodos. Se estudiaron 61 pacientes diagnosticados de diabetes mellitus (DM), con sospecha clínica de CI y sin antecedentes de cardiopatía. A todos se les realizó gated-SPECT de perfusión miocárdica post-estrés ergométrico o farmacológico. Se estudió la relación entre los valores de fracción de eyección y los volúmenes ventriculares con los resultados del estudio de perfusión, el diagnóstico final, la severidad de los defectos de perfusión y la evolución clínica. El tiempo medio de seguimiento fue de 14 meses. Resultados. Todos los valores de función ventricular mostraron, aisladamente, diferencias significativas entre los grupos con estudio de perfusión normal y patológico, y entre los grupos con diagnóstico final de CI y no CI. Tras regresión logística multivariante, el volumen telediastólico (VTD) fue el único valor que mostró asociación estadística con la obtención de un estudio patológico de perfusión, con la severidad del mismo y con el diagnóstico final de CI. No se observó asociación estadística entre los valores de función ventricular y la presencia de eventos cardíacos. Conclusiones. Todos los valores de función ventricular obtenidos mediante gated-SPECT añaden información diagnóstica al estudio de perfusión miocárdica post-estrés en la población diabética con sospecha de CI; sin embargo, sólo el VTD muestra asociación estadística con la obtención de un estudio patológico de perfusión, con la severidad del mismo y con el diagnóstico final de CI

Objective. To assess the clinical usefulness of left ventricular function values obtained using post-stress myocardial perfusion gated-SPECT in diabetic patients with suspected ischaemic heart disease (IHD). Materials and methods. Sixty-one patients with diabetes mellitus (DM), with clinical suspicion of IHD and no previous history of heart disease were studied. Ergometric or pharmacological post-stress myocardial perfusion gated-SPECT was performed on all patients. The relationship between the ejection fraction values and ventricular volumes, and the perfusion study results, final diagnosis, severity of the perfusion defects and the clinical evolution was studied. The mean follow-up time was 14 months. Results. All the ventricular function values independently showed significant differences between the groups with a normal and pathological perfusion study, and between groups with a final diagnosis of IHD and non-IHD. After multivariate logistic regression, the end-diastolic volume (EDV) was the only value which showed a statistical association with the pathological perfusion study, its severity and the final diagnosis of IHD. No statistical association was observed between the ventricular function values and the occurrence of cardiac events. Conclusions. All the ventricular function values obtained by gated-SPECT added diagnostic information to the post-stress myocardial perfusion study in the diabetic population with suspected IHD; however, only EDV showed a statistical association with the pathological perfusion study, severity of defects and the final diagnosis of IHD