Clinical applicability of diagnostic biomarkers in early-onset cognitive impairment.

BACKGROUND AND PURPOSE: Several diagnostic biomarkers are currently available for clinical use in early-onset cognitive impairment. The decision on which biomarker is used in each patient depends on several factors such as its predictive value or tolerability. METHODS: There were a total of 40 subjects with early-onset cognitive complaints (<65 years of age): 26 with Alzheimer's disease (AD), five with frontotemporal dementia and nine with diagnostic suspicion of non-neurodegenerative disorder. Clinical and neuropsychological evaluation, lumbar puncture for cerebrospinal fluid (CSF) AD core biochemical marker determination, medial temporal atrophy evaluation on magnetic resonance imaging, amyloid-positron emission tomography (PET) and 18 F-fluorodeoxyglucose-PET were performed. Neurologists provided pre- and post-biomarker diagnosis, together with diagnostic confidence and clinical/therapeutic management. Patients scored the tolerability of each procedure. RESULTS: Cerebrospinal fluid biomarkers and amyloid-PET increased diagnostic confidence in AD (77.4%-86.2% after CSF, 92.4% after amyloid-PET, P < 0.01) and non-neurodegenerative conditions (53.6%-75% after CSF, 95% after amyloid-PET, P < 0.05). Biomarker results led to diagnostic (32.5%) and treatment (32.5%) changes. All tests were well tolerated. CONCLUSIONS: Biomarker procedures are well tolerated and have an important diagnostic/therapeutic impact on early-onset cognitive impairment.

Correlations between plasma and PET beta-amyloid levels in individuals with subjective cognitive decline: the Fundació ACE Healthy Brain Initiative (FACEHBI).

BACKGROUND: Peripheral biomarkers that identify individuals at risk of developing Alzheimer's disease (AD) or predicting high amyloid beta (Aß) brain burden would be highly valuable. To facilitate clinical trials of disease-modifying therapies, plasma concentrations of Aß species are good candidates for peripheral AD biomarkers, but studies to date have generated conflicting results. METHODS: The Fundació ACE Healthy Brain Initiative (FACEHBI) study uses a convenience sample of 200 individuals diagnosed with subjective cognitive decline (SCD) at the Fundació ACE (Barcelona, Spain) who underwent amyloid florbetaben(18F) (FBB) positron emission tomography (PET) brain imaging. Baseline plasma samples from FACEHBI subjects (aged 65.9 ± 7.2 years) were analyzed using the ABtest (Araclon Biotech). This test directly determines the free plasma (FP) and total plasma (TP) levels of Aß40 and Aß42 peptides. The association between Aß40 and Aß42 plasma levels and FBB-PET global standardized uptake value ratio (SUVR) was determined using correlations and linear regression-based methods. The effect of the APOE genotype on plasma Aß levels and FBB-PET was also assessed. Finally, various models including different combinations of demographics, genetics, and Aß plasma levels were constructed using logistic regression and area under the receiver operating characteristic curve (AUROC) analyses to evaluate their ability for discriminating which subjects presented brain amyloidosis. RESULTS: FBB-PET global SUVR correlated weakly but significantly with Aß42/40 plasma ratios. For TP42/40, this observation persisted after controlling for age and APOE ε4 allele carrier status (R2 = 0.193, p = 1.01E-09). The ROC curve demonstrated that plasma Aß measurements are not superior to APOE and age in combination in predicting brain amyloidosis. It is noteworthy that using a simple preselection tool (the TP42/40 ratio with an empirical cut-off value of 0.08) optimizes the sensitivity and reduces the number of individuals subjected to Aß FBB-PET scanners to 52.8%. No significant dependency was observed between APOE genotype and plasma Aß measurements (p value for interaction = 0.105). CONCLUSION: Brain and plasma Aß levels are partially correlated in individuals diagnosed with SCD. Aß plasma measurements, particularly the TP42/40 ratio, could generate a new recruitment strategy independent of the APOE genotype that would improve identification of SCD subjects with brain amyloidosis and reduce the rate of screening failures in preclinical AD studies. Independent replication of these findings is warranted.

Correlación de la captación de 18F-FDG de la PET/TC con el Ki67 de la inmunohistoquímica en el cáncer epitelial de ovario pretratamiento / Correlation of 18F-FDG uptake on PET/CT with Ki67 immunohistochemistry in pre-treatment epithelial ovarian cancer

Objetivo. El Standardized uptake value (SUV) y los parámetros volumétricos volumen metabólico tumoral (MTV) y glicolisis total de la lesión (TLG) de la 18F-FDG PET/TC son útiles para determinar el pronóstico preoperatorio y postratamiento del cáncer epitelial de ovario (CEO). El Ki67 es otro marcador pronóstico en el CEO asociado con la agresividad tumoral. El objetivo fue estudiar la asociación entre los parámetros de la 18F-FDG PET/TC y el Ki67 en el CEO pretratamiento para determinar si la PET/TC puede predecir la agresividad tumoral de forma no invasiva. Material y métodos. Se realizó una PET/TC a 18 pacientes con sospecha o recién diagnóstico de CEO. Se obtuvo el SUV máximo (SUVmax), SUV medio (SUVmean) y el MTV y la TLG corporal (wbMTV y wbTLG, respectivamente), con un dintel del 30%-40% del SUVmax. Se estimó el índice de Ki67 (medio y máximo) en muestras del tejido tumoral, y se correlacionó con los parámetros de la PET. Resultados. La edad media fue 57,0 años (desviación estándar 13,6 años). Se observó una moderada correlación entre el Ki67 medio y el SUVmax (r=0.392), SUVmean 30% (r=0.437) y SUVmean 40% (r=0.443), así como entre el Ki67 máximo y el SUVmax (r=0.360), SUVmean 30% (r=0.362) y SUVmean 40% (r=0.319). La correlación fue más débil, e inversamente negativa, entre el Ki67 medio y máximo y los parámetros volumétricos de la PET. No hubo diferencias estadísticamente significativas entre las correlaciones. Conclusiones. SUVmax y SUVmean se correlacionaron moderadamente con el Ki67 mientras que los parámetros volumétricos mostraron una correlación débil. SUVmax y SUVmean podrían utilizarse para predecir la agresividad tumoral en el CEO pretratamiento (AU)

Objective. Standardised uptake value (SUV) and volumetric parameters such as metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from 18F-FDG PET/CT are useful criteria for disease prognosis in pre-operative and post-treatment epithelial ovarian cancer (EOC). Ki67 is another prognostic biomarker in EOC, associated with tumour aggressiveness. The aim of this study is to evaluate the association between 18F-FDG PET/CT measurements and Ki67 in pre-treatment EOC to determine if PET/CT parameters could non-invasively predict tumour aggressiveness. Material and methods. A pre-treatment PET/CT was performed on 18 patients with suspected or newly diagnosed EOC. Maximum SUV (SUVmax), mean SUV (SUVmean), whole-body MTV (wbMTV), and whole-body TLG (wbTLG) with a threshold of 30% and 40% of the SUVmax were obtained. Furthermore, Ki67 index (mean and hotspot) was estimated in tumour tissue specimens. Immunohistochemical findings were correlated with PET parameters. Results. The mean age was 57.0 years old (standard deviation 13.6 years). A moderate correlation was observed between mean Ki67 index and SUVmax (r=0.392), SUVmean 30% (r=0.437), and SUVmean 40% (r=0.443), and also between hotspot Ki67 index and SUVmax (r=0.360), SUVmean 30% (r=0.362) and SUVmean 40% (r=0.319). There was a weaker correlation, which was inversely negative, between mean and hotspot Ki67 and volumetric PET parameters. However, no statistical significant differences were found for any correlations. Conclusions. SUVmax and SUVmean were moderately correlated with Ki67 index, whereas volumetric PET parameters overall, showed a weaker correlation. Thus, SUVmax and SUVmean could be used to assess tumour aggressiveness in pre-treatment EOC (AU)

Correlation of 18F-FDG uptake on PET/CT with Ki67 immunohistochemistry in pre-treatment epithelial ovarian cancer. / Correlación de la captación de 18F-FDG de la PET/TC con el Ki67 de la inmunohistoquímica en el cáncer epitelial de ovario pretratamiento.

OBJECTIVE: Standardised uptake value (SUV) and volumetric parameters such as metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from 18F-FDG PET/CT are useful criteria for disease prognosis in pre-operative and post-treatment epithelial ovarian cancer (EOC). Ki67 is another prognostic biomarker in EOC, associated with tumour aggressiveness. The aim of this study is to evaluate the association between 18F-FDG PET/CT measurements and Ki67 in pre-treatment EOC to determine if PET/CT parameters could non-invasively predict tumour aggressiveness. MATERIAL AND METHODS: A pre-treatment PET/CT was performed on 18 patients with suspected or newly diagnosed EOC. Maximum SUV (SUVmax), mean SUV (SUVmean), whole-body MTV (wbMTV), and whole-body TLG (wbTLG) with a threshold of 30% and 40% of the SUVmax were obtained. Furthermore, Ki67 index (mean and hotspot) was estimated in tumour tissue specimens. Immunohistochemical findings were correlated with PET parameters. RESULTS: The mean age was 57.0 years old (standard deviation 13.6 years). A moderate correlation was observed between mean Ki67 index and SUVmax (r=0.392), SUVmean 30% (r=0.437), and SUVmean 40% (r=0.443), and also between hotspot Ki67 index and SUVmax (r=0.360), SUVmean 30% (r=0.362) and SUVmean 40% (r=0.319). There was a weaker correlation, which was inversely negative, between mean and hotspot Ki67 and volumetric PET parameters. However, no statistical significant differences were found for any correlations. CONCLUSIONS: SUVmax and SUVmean were moderately correlated with Ki67 index, whereas volumetric PET parameters overall, showed a weaker correlation. Thus, SUVmax and SUVmean could be used to assess tumour aggressiveness in pre-treatment EOC.

FACEHBI: A Prospective Study of Risk Factors, Biomarkers and Cognition in a Cohort of Individuals with Subjective Cognitive Decline. Study Rationale and Research Protocols.

BACKGROUND: Long-term longitudinal studies with multimodal biomarkers are needed to delve into the knowledge of preclinical AD. Subjective cognitive decline has been proposed as a risk factor for the development of cognitive impairment. Thus, including individuals with SCD in observational studies may be a cost-effective strategy to increase the prevalence of preclinical AD in the sample. OBJECTIVES: To describe the rationale, research protocols and baseline characteristics of participants in the Fundació ACE Healthy Brain Initiative (FACEHBI). DESIGN: FACEHBI is a clinical trial (EudraCT: 2014-000798-38) embedded within a long-term observational study of individuals with SCD. SETTING: Participants have been recruited at the memory clinic of Fundació ACE (Barcelona) from two different sources: patients referred by a general practitioner and individuals from an Open House Initiative. PARTICIPANTS: 200 individuals diagnosed with SCD with a strictly normal performance in a comprehensive neuropsychological battery. MEASUREMENTS: Individuals will undergo an extensive neuropsychological protocol, risk factor assessment and a set of multimodal biomarkers including florbetaben PET, structural and functional MRI, diffusion tensor imaging, determination of amyloid species in plasma and neurophthalmologic assessment with optical coherence tomography. RESULTS: Two hundred individuals have been recruited in 15 months. Mean age was 65.9 years; mean MMSE was 29.2 with a mean of 14.8 years of education. CONCLUSIONS: FACEHBI is a long-term study of cognition, biomarkers and lifestyle that has been designed upon an innovative symptom-based approach using SCD as target population. It will shed light on the pathophysiology of preclinical AD and the role of SCD as a risk marker for the development of cognitive impairment.

18F-FDG PET/CT and sentinel lymph node biopsy in the staging of patients with cervical and endometrial cancer. Role of dual-time-point imaging / PET/TC con 18F-FDG y biopsia del ganglio centinela en la estadificación de pacientes con cáncer de cérvix y endometrio. Utilidad de la imagen dual-time-point

Objective. Definitive staging for cervical (CC) and endometrial cancer (EC) takes place once surgery is performed. The aim of this study was to evaluate the role of PET/CT in detecting lymphatic metastasis in patients with CC and EC using dual-time-point imaging (DPI), taking the histopathological results of sentinel lymph node (SLN) and lymphadenectomy as the reference. Material and methods. A prospective study was conducted on 17 patients with early CC, and 13 patients with high-risk EC. The patients had a pre-operative PET/CT, MRI, SLN detection, and lymphadenectomy, when indicated. PET/CT findings were compared with histopathological results. Results. In the pathology study, 4 patients with CC and 4 patients with EC had lymphatic metastasis. PET/CT showed hypermetabolic nodes in 1 patient with CC, and 5 with EC. Four of these had metastasis, one detected in the SLN biopsy. Four patients who had negative PET/CT had micrometastasis in the SLN biopsy, 1 patient with additional lymph nodes involvement. The overall patient-based sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT to detect lymphatic metastasis was 20.0%, 100.0%, 100.0%, 87.9%, and 88.2%, respectively, in CC, and 57.1%, 88.9%, 66.7%, 84.2% and 80.0%, respectively, in EC. DPI showed higher retention index in malignant than in inflammatory nodes, although no statistically significant differences were found. Conclusions. PET/CT has low sensitivity in lymph node staging of CC and EC, owing to the lack of detection of micrometastasis. Thus, PET/CT cannot replace SLN biopsy. Although no statistically significant differences were found, DPI may help to differentiate between inflammatory and malignant nodes (AU)

Objetivo. La estadificación definitiva del cáncer de cérvix (CC) y de endometrio (CE) tiene lugar tras la cirugía. Nuestro objetivo fue evaluar la utilidad de la PET/TC para la detección de metástasis ganglionares en el CC y en el CE con imagen dual-time-point (DPI), considerando como gold standard la histopatología del ganglio centinela (GC) y la linfadenectomía. Material y métodos. Diecisiete pacientes con CC inicial y 13 con CE de alto riesgo fueron incluidas prospectivamente. Preoperatoriamente se realizó una PET/TC, RM, detección del GC y linfadenectomía en los casos indicados. Se comparó la PET/TC con la histopatología. Resultados. En el estudio anatomopatológico, 4 pacientes con CC y 4 con CE tuvieron metástasis ganglionares. La PET/TC mostró ganglios hipermetabólicos en una paciente con CC y en 5 con CE. Cuatro de ellas tenían metástasis, una detectada en el GC. Cuatro pacientes con PET/TC negativa presentaron micrometástasis en el GC, una paciente con ganglios adicionales infiltrados. La sensibilidad, especificidad, valor predictivo positivo y negativo y la exactitud diagnóstica de la PET/TC para detectar metástasis ganglionares fueron 20,0; 100,0; 100,0; 87,9 y 88,2% para el CC, y 57,1; 88,9; 66,7; 84,2 y 80,0% para el CE. La DPI mostró un índice de retención superior en ganglios infiltrados respecto a los inflamatorios, sin hallar diferencias estadísticamente significativas. Conclusiones. La PET/TC tiene baja sensibilidad para estadificar el CC y CE por la incapacidad de detectar micrometástasis y, por tanto, no sustituye la detección del GC. Aunque no hubo diferencias estadísticamente significativas, la DPI podría ayudar a diferenciar ganglios inflamatorios de tumorales (AU)

18F-FDG PET/CT and sentinel lymph node biopsy in the staging of patients with cervical and endometrial cancer. Role of dual-time-point imaging.

OBJECTIVE: Definitive staging for cervical (CC) and endometrial cancer (EC) takes place once surgery is performed. The aim of this study was to evaluate the role of PET/CT in detecting lymphatic metastasis in patients with CC and EC using dual-time-point imaging (DPI), taking the histopathological results of sentinel lymph node (SLN) and lymphadenectomy as the reference. MATERIAL AND METHODS: A prospective study was conducted on 17 patients with early CC, and 13 patients with high-risk EC. The patients had a pre-operative PET/CT, MRI, SLN detection, and lymphadenectomy, when indicated. PET/CT findings were compared with histopathological results. RESULTS: In the pathology study, 4 patients with CC and 4 patients with EC had lymphatic metastasis. PET/CT showed hypermetabolic nodes in 1 patient with CC, and 5 with EC. Four of these had metastasis, one detected in the SLN biopsy. Four patients who had negative PET/CT had micrometastasis in the SLN biopsy, 1 patient with additional lymph nodes involvement. The overall patient-based sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT to detect lymphatic metastasis was 20.0%, 100.0%, 100.0%, 87.9%, and 88.2%, respectively, in CC, and 57.1%, 88.9%, 66.7%, 84.2% and 80.0%, respectively, in EC. DPI showed higher retention index in malignant than in inflammatory nodes, although no statistically significant differences were found. CONCLUSIONS: PET/CT has low sensitivity in lymph node staging of CC and EC, owing to the lack of detection of micrometastasis. Thus, PET/CT cannot replace SLN biopsy. Although no statistically significant differences were found, DPI may help to differentiate between inflammatory and malignant nodes.

Dual time-point 18F-FDG PET/CT to assess response to radiofrequency ablation of lung metastases / Imágenes en 2 tiempos con 18F-FDG PET/TC para evaluar la ablación por radiofrecuencia de las metástasis pulmonares

Aim. To establish the usefulness of dual time-point PET/CT imaging in determining the response to radiofrequency ablation (RFA) of solitary lung metastases from gastrointestinal cancer. Materials and methods. This prospective study included 18 cases (3 female, 15 male, mean age 71 ± 15 yrs) with solitary lung metastases from malignant digestive tract tumors candidates for RFA. PET/CT images 1 h after injection of 4.07 MBq/kg of 18F-FDG (standard images) were performed at baseline, 1 month, and 3 months after RFA. PET/CT images 2 h after injection centered in the thorax at 1 month after RFA were also performed (delayed images). A retention index (RI) of dual time-point images was calculated as follows: RI = (SUVmax delayed image − SUVmax standard image/SUVmax standard image) * 100. Pathological confirmation of residual tumor by histology of the treated lesion was considered as local recurrence. A negative imaging follow-up was considered as complete response. Results. Local recurrence was found in 6/18 lesions, and complete response in the remaining 12. The mean percentage change in SUVmax at 1 month and at 3 months showed a sensitivity and specificity for PET/CT of 50% and 33%, and 67% and 92%, respectively. The RI at 1 month after RFA showed a sensitivity and specificity of 83% and 92%, respectively. Conclusions. Dual time point PET/CT can predict the outcome at one month after RFA in lung metastases from digestive tract cancers. The RI can be used to indicate the need for further procedures to rule out persistent tumor due to incomplete RFA (AU)

Objetivo. Establecer la utilidad de las imágenes PET/TC en 2 tiempos en la determinación de la respuesta a la ablación por radiofrecuencia (RFA) de las metástasis pulmonares de tumores digestivos. Material y métodos. Estudio prospectivo con 18 casos (3 mujeres, 15 varones) y edad media de 71 ± 15 años con metástasis pulmonar única de cáncer digestivo candidato a tratamiento mediante RFA. Se realizaron imágenes PET/CT 1 h tras inyección de 4,07 MBq/Kg de 18F-FDG (imagen estándar) basal, un mes y 3 meses después de la RFA y una imagen tardía 2 h tras la inyección centrada en tórax un mes después de la RFA. Se calculó el índice de retención (RI): RI = (SUVmáx imagen tardía − SUVmáx imagen estándar/SUVmáx imagen estándar) * 100. La recurrencia local se confirmó con estudio histológico de la lesión tratada con RFA. Un resultado negativo en las pruebas de imagen durante el seguimiento se consideró como respuesta completa. Resultados. Se diagnosticó recidiva local en 6/18 lesiones y respuesta completa en 12/18. El cambio porcentual medio de SUVmáx al mes y a los 3 meses mostró una sensibilidad y especificidad para evaluar la respuesta a la RFA de 50% y 33% y 67% y 92%, respectivamente. El RI un mes posradiofrecuencia mostró una sensibilidad y especificidad del 83% y 92%. Conclusiones. Las imágenes en 2 tiempos con PET/TC un mes posradiofrecuencia pueden predecir el resultado de la RFA de las metástasis pulmonares de origen digestivo. El RI se puede utilizar para indicar la necesidad de otros procedimientos para descartar recurrencia tumoral debido a una RFA incompleta (AU)

Update on PET/CT colonography in the diagnosis of colorectal cancer / Actualización sobre la utilidad de la PET/TC colonografía en el diagnóstico del cáncer colorrectal

No disponible

Prognostic value of 18F-FDG PET/CT volumetric parameters in recurrent epithelial ovarian cancer / Valor pronóstico de los parámetros volumétricos de la 18F-FDG PET/TC en el cáncer epitelial de ovario recurrente

Objective. Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from 18F-FDG PET/CT are emerging prognostic biomarkers in various solid neoplasms. These volumetric parameters and the SUVmax have shown to be useful criteria for disease prognostication in preoperative and post-treatment epithelial ovarian cancer (EOC) patients. The purpose of this study was to evaluate the utility of 18F-FDG PET/CT measurements to predict survival in patients with recurrent EOC. Material and methods. Twenty-six patients with EOC who underwent a total of 31 18F-FDG PET/CT studies for suspected recurrence were retrospectively included. SUVmax and volumetric parameters whole-body MTV (wbMTV) and whole-body TLG (wbTLG) with a threshold of 40% and 50% of the SUVmax were obtained. Correlation between PET parameters and progression-free survival (PFS) and the survival analysis of prognostic factors were calculated. Results. Serous cancer was the most common histological subtype (76.9%). The median PFS was 12.5 months (range 10.7-20.6 months). Volumetric parameters showed moderate inverse correlation with PFS but there was no significant correlation in the case of SUVmax. The correlation was stronger for first recurrences. By Kaplan-Meier analysis and log-rank test, wbMTV 40%, wbMTV 50% and wbTLG 50% correlated with PFS. However, SUVmax and wbTLG 40% were not statistically significant predictors for PFS. Conclusion. Volumetric parameters wbMTV and wbTLG 50% measured by 18F-FDG PET/CT appear to be useful prognostic predictors of outcome and may provide valuable information to individualize treatment strategies in patients with recurrent EOC (AU)

Objetivo. El metabolic tumour volume (MTV) y la total lesion glycolysis (TLG) obtenidos de la 18F-FDG PET/TC son biomarcadores pronósticos emergentes en varias neoplasias. Estos parámetros volumétricos junto con el SUVmax son útiles para determinar el pronóstico preoperatorio y post-tratamiento de las pacientes con cáncer epitelial de ovario (CEO). El objetivo fue determinar la utilidad de los parámetros de la 18F-FDG PET/TC para predecir la supervivenvia de las pacientes con CEO recurrente. Material y métodos. Se incluyeron retrospectivamente 26 pacientes con CEO a las que se les realizó 31 estudios 18F-FDG PET/TC por sospecha de recidiva. Se obtuvo el valor del SUVmax, whole-body MTV (wbMTV) y whole-body TLG (wbTLG) con un umbral del 40% y 50% del SUVmax. Se estimó la correlación entre los parámetros PET y el intervalo libre de progresión (ILP) y se realizó análisis de supervivencia segun factores pronósticos. Resultados. El subtipo histológico más frecuente fue cáncer seroso (76,9%). La mediana del ILP fue 12,5 meses (rango 10,7-20,6 meses). Se observó correlación inversa moderada entre los parámetros volumétricos e ILP, sin evidenciar correlación significativa con SUVmax. La correlación fue más fuerte para primeras recidivas. Las curvas de supervivencia mostraron correlación entre wbMTV 40%, wbMTV 50% y wbTLG 50% con ILP. SUVmax y wbTLG 40% no fueron predictores de ILP de forma estadísticamente significativa. Conclusión. Los parámetros wbMTV y wbTLG 50% de la 18F-FDG PET/TC podrían utilizarse como factores pronósticos ofreciendo una valiosa información para individualizar el tratamiento de las pacientes con CEO recurrente (AU)

Dual time-point (18)F-FDG PET/CT to assess response to radiofrequency ablation of lung metastases.

AIM: To establish the usefulness of dual time-point PET/CT imaging in determining the response to radiofrequency ablation (RFA) of solitary lung metastases from gastrointestinal cancer. MATERIALS AND METHODS: This prospective study included 18 cases (3 female, 15 male, mean age 71±15 yrs) with solitary lung metastases from malignant digestive tract tumors candidates for RFA. PET/CT images 1h after injection of 4.07MBq/kg of (18)F-FDG (standard images) were performed at baseline, 1 month, and 3 months after RFA. PET/CT images 2h after injection centered in the thorax at 1 month after RFA were also performed (delayed images). A retention index (RI) of dual time-point images was calculated as follows: RI=(SUVmax delayed image-SUVmax standard image/SUVmax standard image)*100. Pathological confirmation of residual tumor by histology of the treated lesion was considered as local recurrence. A negative imaging follow-up was considered as complete response. RESULTS: Local recurrence was found in 6/18 lesions, and complete response in the remaining 12. The mean percentage change in SUVmax at 1 month and at 3 months showed a sensitivity and specificity for PET/CT of 50% and 33%, and 67% and 92%, respectively. The RI at 1 month after RFA showed a sensitivity and specificity of 83% and 92%, respectively. CONCLUSIONS: Dual time point PET/CT can predict the outcome at one month after RFA in lung metastases from digestive tract cancers. The RI can be used to indicate the need for further procedures to rule out persistent tumor due to incomplete RFA.

Prognostic value of (18)F-FDG PET/CT volumetric parameters in recurrent epithelial ovarian cancer.

OBJECTIVE: Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various solid neoplasms. These volumetric parameters and the SUVmax have shown to be useful criteria for disease prognostication in preoperative and post-treatment epithelial ovarian cancer (EOC) patients. The purpose of this study was to evaluate the utility of (18)F-FDG PET/CT measurements to predict survival in patients with recurrent EOC. MATERIAL AND METHODS: Twenty-six patients with EOC who underwent a total of 31 (18)F-FDG PET/CT studies for suspected recurrence were retrospectively included. SUVmax and volumetric parameters whole-body MTV (wbMTV) and whole-body TLG (wbTLG) with a threshold of 40% and 50% of the SUVmax were obtained. Correlation between PET parameters and progression-free survival (PFS) and the survival analysis of prognostic factors were calculated. RESULTS: Serous cancer was the most common histological subtype (76.9%). The median PFS was 12.5 months (range 10.7-20.6 months). Volumetric parameters showed moderate inverse correlation with PFS but there was no significant correlation in the case of SUVmax. The correlation was stronger for first recurrences. By Kaplan-Meier analysis and log-rank test, wbMTV 40%, wbMTV 50% and wbTLG 50% correlated with PFS. However, SUVmax and wbTLG 40% were not statistically significant predictors for PFS. CONCLUSION: Volumetric parameters wbMTV and wbTLG 50% measured by (18)F-FDG PET/CT appear to be useful prognostic predictors of outcome and may provide valuable information to individualize treatment strategies in patients with recurrent EOC.

Validation of semi-quantitative methods for DAT SPECT: influence of anatomical variability and partial volume effect.

The aim of this work was to evaluate the influence of anatomical variability between subjects and of the partial volume effect (PVE) on the standardized Specific Uptake Ratio (SUR) in [(123)I]FP-bib SPECT studies. To this end, magnetic resonance (MR) images of 23 subjects with differences in the striatal volume of up to 44% were segmented and used to generate a database of 138 Monte Carlo simulated SPECT studies. Data included normal uptakes and pathological cases. Studies were reconstructed by filtered back projection (FBP) and the ordered-subset expectation-maximization algorithm. Quantification was carried out by applying a reference method based on regions of interest (ROIs) derived from the MR images and ROIs derived from the Automated Anatomical Labelling map. Our results showed that, regardless of anatomical variability, the relationship between calculated and true SUR values for caudate and putamen could be described by a multiple linear model which took into account the spill-over phenomenon caused by PVE (R² ≥ 0.963 for caudate and ≥0.980 for putamen) and also by a simple linear model (R(2) ≥ 0.952 for caudate and ≥0.973 for putamen). Calculated values were standardized by inverting both linear systems. Differences between standardized and true values showed that, although the multiple linear model was the best approach in terms of variability (X² ≥ 11.79 for caudate and ≤7.36 for putamen), standardization based on a simple linear model was also suitable (X² ≥ 12.44 for caudate and ≤12.57 for putamen).

11C-Choline PET/CT in the primary diagnosis of prostate cancer: impact on treatment planning.

AIM: Aim of the present study was to evaluate the usefulness of 11C-choline PET/CT for detecting lymphatic or haematogenous spread and for planning radiotherapy in patients with medium-to-high risk prostate cancer. METHODS: We have included 61 consecutive patients recently diagnosed with cancer prostate by biopsy. All patients were classified as medium-to-high risk: Gleason: 7-9; PSA: 6.3-30.4 ng/mL; stage T2c (N.=20) or stage T3 (N.=41). Image acquisition began 5 min after intravenous injection of 11C-choline (656+119 MBq), starting at the pelvis and continuing craniocaudally. Images were interpreted visually to evaluate uptake by the prostate gland. Lymph nodes with 11C-choline uptake were considered invaded, regardless of their size. Bone lesions were considered positive when they showed greater focal uptake than the surrounding bone. In patients with evidence of lymph-node invasion or bone metastases (15 patients), disease was classified as locoregional, oligometastatic, or multimetastatic. RESULTS: All patients had prostate gland uptake (20 focal, 8 bifocal, and 33 multifocal). Extraprostatic disease was present in 15 patients (24.6%), as follows: 9 (60%) in a single location: in an infradiaphragmatic lymph node (N.=6), in a supradiaphragmatic lymph node (N.=1), and in bone (M1) (N.=2). Six (40%) as multifocal invasion: with both infra- and supradiaphragmatic lymph node involvement (N.=2); with infradiaphragmatic lymph node involvement and M1 bone metastases (N.=3); and infra- and supradiaphragmatic lymph node involvement plus M1 bone metastases (N.=1). Disease was classified as locoregional (N.=6), oligometastatic (N.=5), and multimetastatic (N.=4). The 11 (73.3%) patients with locoregional and oligometastatic disease were selected to undergo intensity-modulated radiation therapy with dose escalation based on the PET findings. CONCLUSION: Our results suggest that 11C-choline PET/CT is a useful one-stop diagnostic procedure for evaluating patients with medium/high risk prostate cancer scheduled for radical treatment. 11C-choline PET/CT can reliably rule out lymph node involvement and remote metastases, allowing to select candidates for radiotherapy and to plan their treatment.

Neuroimagen funcional en el diagnóstico de pacientes con síndrome parkinsoniano: actualización y recomendaciones para el uso clínico / Functional neuroimaging in the diagnosis of patients with Parkinsonism: Update and recommendations for clinical use

Las técnicas de neuroimagen funcional se han utilizado tradicionalmente en la investigación de los pacientes que presentan un síndrome parkinsoniano. Sin embargo, la aparición de radiofármacos comerciales junto a la disponibilidad de equipos de tomografía por emisión de fotón único (SPECT) y más recientemente de la tomografía por emisión de positrones (PET), han permitido su empleo rutinario en la práctica clínica. Precisamente el desarrollo y grado de evidencia clínica alcanzado por los biomarcadores de neuroimagen durante las 2 últimas décadas ha conllevado que progresivamente se estén incluyendo en los criterios clínicos de diagnóstico de enfermedades neurodegenerativas que cursan con un síndrome parkinsoniano. No obstante, la diversidad de radiofármacos que permiten evaluar la funcionalidad de las vías anatómicas involucradas en la neurodegeneración presente en los diferentes síndromes parkinsonianos (vía nigroestriatal dopaminérgica, actividad neuronal de los ganglios basales y la corteza, inervación simpática miocárdica), junto a las técnicas de neuroimagen (gammagrafía, SPECT y PET) han originado cierta controversia con respecto a la indicación de las pruebas de neuroimagen como exploración complementaria. En esta revisión realizada por un panel de expertos en medicina nuclear y neurología se analizan las técnicas de neuroimagen funcional disponibles haciendo especial énfasis en las consideraciones prácticas del diagnóstico de pacientes con un síndrome parkinsoniano de origen incierto y la valoración de la progresión de la enfermedad de Parkinson (AU)

Functional Neuroimaging has been traditionally used in research for patients with different Parkinsonian syndromes. However, the emergence of commercial radiotracers together with the availability of single photon emission computed tomography (SPECT) and, more recently, positron emission tomography (PET) have made them available for clinical practice. Particularly, the development of clinical evidence achieved by functional neuroimaging techniques over the past two decades have motivated a progressive inclusion of several biomarkers in the clinical diagnostic criteria for neurodegenerative diseases that occur with Parkinsonism. However, the wide range of radiotracers designed to assess the involvement of different pathways in the neurodegenerative process underlying Parkinsonian syndromes (dopaminergic nigrostriatal pathway integrity, basal ganglia and cortical neuronal activity, myocardial sympathetic innervation), and the different neuroimaging techniques currently available (scintigraphy, SPECT and PET), have generated some controversy concerning the best neuroimaging test that should be indicated for the differential diagnosis of Parkinsonism. In this article, a panel of nuclear medicine and neurology experts has evaluated the functional neuroimaging techniques emphazising practical considerations related to the diagnosis of patients with uncertain origin parkinsonism and the assessment Parkinson’s disease progression (AU)

PET y SPECT en la epilepsia / PET and SPECT in epilepsy

La epilepsia es uno de los trastornos neurológicos crónicos más frecuentes, afectando al 1-2% de la población. Los pacientes con crisis parciales complejas resistentes al tratamiento farmacológico pueden beneficiarse de un tratamiento quirúrgico que consiste en la extirpación de la zona epileptógena. Clásicamente la localización de la zona epilpetógena se realiza con vídeo-EEG y resonancia magnética (RM). Recientemente las exploraciones de neuroimagen funcional de medicina nuclear, la tomografía por emisión de positrones (PET) y la tomografía por emisión de fotón único (SPECT) han demostrado utilidad en la localización de la zona epileptógena antes de la cirugía. La SPECT ictal con trazadores de perfusión cerebral demuestra un aumento del flujo sanguíneo en la zona de inicio ictal, mientras que la PET con 18FDG muestra una disminución del metabolismo de la glucosa en la zona de déficit funcional interictal. En esta revisión se describen los principios básicos y las particularidades metodológicas de la SPECT y la PET en la epilepsia. Se detalla el mecanismo de inyección de la SPECT ictal, los diferentes patrones de perfusión en función del momento de inyección ictal, postictal o interictal y se revisan las diferentes sensibilidades diagnósticas de cada uno de estos SPECT. Se describen diferentes métodos de análisis de las imágenes con sistemas de substracción y fusión con la RM. Del mismo modo, se describe la metodología de inyección, cuantificación y evaluación de las imágenes de la PET en la epilepsia. Finalmente se detallan las principales indicaciones clínicas de la SPECT y de la PET en la epilepsia temporal y extratemporal (AU)

Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with 18FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed (AU)

[Functional neuroimaging in the diagnosis of patients with Parkinsonism: Update and recommendations for clinical use]. / Neuroimagen funcional en el diagnóstico de pacientes con síndrome parkinsoniano: actualización y recomendaciones para el uso clínico.

Functional Neuroimaging has been traditionally used in research for patients with different Parkinsonian syndromes. However, the emergence of commercial radiotracers together with the availability of single photon emission computed tomography (SPECT) and, more recently, positron emission tomography (PET) have made them available for clinical practice. Particularly, the development of clinical evidence achieved by functional neuroimaging techniques over the past two decades have motivated a progressive inclusion of several biomarkers in the clinical diagnostic criteria for neurodegenerative diseases that occur with Parkinsonism. However, the wide range of radiotracers designed to assess the involvement of different pathways in the neurodegenerative process underlying Parkinsonian syndromes (dopaminergic nigrostriatal pathway integrity, basal ganglia and cortical neuronal activity, myocardial sympathetic innervation), and the different neuroimaging techniques currently available (scintigraphy, SPECT and PET), have generated some controversy concerning the best neuroimaging test that should be indicated for the differential diagnosis of Parkinsonism. In this article, a panel of nuclear medicine and neurology experts has evaluated the functional neuroimaging techniques emphazising practical considerations related to the diagnosis of patients with uncertain origin parkinsonism and the assessment Parkinson's disease progression.