Omics-derived biological modules reflect metabolic brain changes in Alzheimer's disease.

INTRODUCTION: Brain glucose hypometabolism, indexed by the fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) imaging, is a metabolic signature of Alzheimer's disease (AD). However, the underlying biological pathways involved in these metabolic changes remain elusive. METHODS: Here, we integrated [18F]FDG-PET images with blood and hippocampal transcriptomic data from cognitively unimpaired (CU, n = 445) and cognitively impaired (CI, n = 749) individuals using modular dimension reduction techniques and voxel-wise linear regression analysis. RESULTS: Our results showed that multiple transcriptomic modules are associated with brain [18F]FDG-PET metabolism, with the top hits being a protein serine/threonine kinase activity gene cluster (peak-t(223) = 4.86, P value < 0.001) and zinc-finger-related regulatory units (peak-t(223) = 3.90, P value < 0.001). DISCUSSION: By integrating transcriptomics with PET imaging data, we identified that serine/threonine kinase activity-associated genes and zinc-finger-related regulatory units are highly associated with brain metabolic changes in AD. HIGHLIGHTS: We conducted an integrated analysis of system-based transcriptomics and fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) at the voxel level in Alzheimer's disease (AD). The biological process of serine/threonine kinase activity was the most associated with [18F]FDG-PET in the AD brain. Serine/threonine kinase activity alterations are associated with brain vulnerable regions in AD [18F]FDG-PET. Zinc-finger transcription factor targets were associated with AD brain [18F]FDG-PET metabolism.

Implementation of positron emission tomography with 18F-fluorodeoxyglucose associated with computed tomography in patients with sarcoidosis. Its effect on disease staging and the therapeutic approach

Objetives: to evaluate the benefit of implementing 18F-FDG PET/TC in the staging and treatment adjustment of patients with sarcoidosis, compared with the signs and symptoms and complementary test results usually employed. Materials and methods: an observational, analytical electronic chart review of a retrospective cohort of patients seen for sarcoidosis in the internal medicine department of a Spanish university hospital. Results: a total of 31 patients (18 males) were evaluated, with an average age of 54.6±14.71 years and 11±5.75 years since their sarcoidosis diagnosis. In the 84.6% of the reviews, positive uptake was objectified on the 18F-FDG PET/TC. In the 42.3% of the occasions, the objectified find ing allowed restaging of the patient. The 18F-FDG PET/TC result justified the choice of treatment in the 71% of the reviews. Conclusions: 18F-FDG PET/TC provided additional advantages in the staging and therapeutic management of patients with sarcoidosis, compared with the evaluation of signs and symptoms and other clinical tests usually employed in follow up, due to its greater accuracy in determining the activity and extension of the disease. (Acta Med Colomb 2022; 48. DOI: https://doi.org/10.36104/amc.2023.2778).

Adenoma hepatocelular con captación de 18 flúor deoxiglucosa en PET-TC SCAN. Una "mini-review" e informe de un nuevo caso / 18-fluoro-deoxyglucose uptake on PET-CT in hepatocellular adenoma. A mini review with a new case Report

RESUMEN La captación de 18 FDG en PET-TC por un adenoma hepatocelular (HCA) es poco frecuente. Esta situación genera dudas en cuanto a los diagnósticos diferenciales y tratamiento. El objetivo de este artículo fue realizar una mini revisión de los últimos 37 años de HCA con avidez por el 18FDG y presentar un nuevo caso. Sobre la base de un estudio realizado por otros autores entre 1984 y 2014, se amplía la búsqueda utilizando las mismas palabras clave hasta el año 2021. Se analizan los datos relevantes. Entre 1984 y 2021 detectamos 38 casos en 37 años. Fue más frecuente en mujeres en edad reproductiva. Los subtipos H-HCA e I-HCA fueron los más frecuentes. El tratamiento quirúrgico fue el más empleado. La diferenciación celular y los trastornos metabólicos de la glucosa y de los lípidos favorecerían la captación de 18FDG. La resección hepática ofrecería mayores garantías permitiendo el estudio completo de la lesión.

ABSTRACT Hepatocellular adenoma (HCA) uptake of 18FDG uptake on PET-CT is rare. This situation poses doubts about the differential diagnoses and treatment. The aim of this article is to perform a mini review of 18FDG avid HCA over the past 37 years and to describe a new case presentation. Based on a study conducted by other authors between 1984 and 2014, we extended the search until 2021 using the same keywords. The relevant data were analyzed. Between 1984 and 2021 we detected 38 cases in 37 years. HCAs were more common in women of childbearing age. The most common types were H-HCA an I-HCA. Surgical resection was the treatment most used. Cell differentiation and glucose and lipid metabolic diseases would favor 18FDG uptake. Liver resection provides better outcomes, allowing for a complete examination of the lesion.

Exploratory analysis of radiomic as prognostic biomarkers in 18F-FDG PET/CT scan in uterine cervical cancer.

Objective: To evaluate the performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) radiomic features to predict overall survival (OS) in patients with locally advanced uterine cervical carcinoma. Methods: Longitudinal and retrospective study that evaluated 50 patients with cervical epidermoid carcinoma (clinical stage IB2 to IVA according to FIGO). Segmentation of the 18F-FDG PET/CT tumors was performed using the LIFEx software, generating the radiomic features. We used the Mann-Whitney test to select radiomic features associated with the clinical outcome (death), excluding the features highly correlated with each other with Spearman correlation. Subsequently, ROC curves and a Kaplan-Meier analysis were performed. A p-value < 0.05 were considered significant. Results: The median follow-up was 23.5 months and longer than 24 months in all surviving patients. Independent predictors for OS were found-SUVpeak with an AUC of 0.74, sensitivity of 77.8%, and specificity of 72.7% (p = 0.006); and the textural feature gray-level run-length matrix GLRLM_LRLGE, with AUC of 0.74, sensitivity of 72.2%, and specificity of 81.8% (p = 0.005). When we used the derived cut-off points from these ROC curves (12.76 for SUVpeak and 0.001 for GLRLM_LRLGE) in a Kaplan-Meier analysis, we can see two different groups (one with an overall survival probability of approximately 90% and the other with 30%). These biomarkers are independent of FIGO staging. Conclusion: By radiomic 18F-FDG PET/CT data analysis, SUVpeak and GLRLM_LRLGE textural feature presented the best performance to predict OS in patients with cervical cancer undergoing chemo-radiotherapy and brachytherapy.

Interictal and postictal 18F-FDG PET/CT in epileptogenic zone localization.

Objective: To evaluate the performance of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography ( 18F-FDG PET/CT) in localizing epileptogenic zones, comparing 18F-FDG injection performed in the traditional interictal period with that performed near the time of a seizure. Materials and Methods: We evaluated patients with refractory epilepsy who underwent 18F-FDG PET/CT. The reference standards for localization of the epileptogenic zone were histopathology and follow-up examinations (in patients who underwent surgery) or serial electroencephalography (EEG) recordings, long-term video EEG, and magnetic resonance imaging (in patients who did not). The 18F-FDG injection was performed whether the patient had an epileptic seizure during the EEG monitoring period or not. The 18F-FDG PET/CT results were categorized as concordant or discordant with the reference standards. Results: Of the 110 patients evaluated, 10 were in a postictal group (FDG injection after a seizure) and 100 were in the interictal group. The 18F-FDG PET/CT was concordant with the reference standards in nine (90%) of the postictal group patients and in 60 (60%) of the interictal group patients. Among the nine postictal group patients in whom the results were concordant, the 18F-FDG PET/CT showed hypermetabolism and hypometabolism in the epileptogenic zone in four (44.4%) and five (55.6%), respectively. Conclusion: Our data indicate that 18F-FDG PET/CT is a helpful tool for localization of the epileptogenic zone and that EEG monitoring is an important means of correlating the findings. In addition, postictal 18F-FDG PET/CT is able to identify the epileptogenic zone by showing either hypometabolism or hypermetabolism.

Objetivo: Avaliar a capacidade da PET/CT FDG detectar a zona epileptogênica, com injeção da FDG realizada tanto no período interictal como perto de uma crise epiléptica. Materiais e Métodos: Foram avaliados pacientes com epilepsia de difícil controle que realizaram PET/CT FDG. A zona epileptogênica foi definida pelo follow up/anatomopatológico ou eletroencefalogramas (EEGs) seriados, telemetria e ressonância magnética. PET/CT FDG foi realizada independentemente se o paciente tinha crise epiléptica durante a monitoração com EEG ou no período interictal. Os resultados foram definidos como concordantes ou discordantes, comparando com a zona epileptogênica. Resultados: Foram incluídos no estudo 110 pacientes: 10 no grupo pós-ictal (injeção de FDG depois da crise) e 100 no grupo interictal. A PET/CT FDG foi concordante com a zona epileptogênica em nove pacientes do grupo pós-ictal (90%) e 60 pacientes do grupo interictal (60%). Entre os nove pacientes concordantes do grupo pós-ictal, quatro mostraram hipermetabolismo (44,4%) e cinco mostraram hipometabolismo na zona epileptogênica (55,6%). Conclusão: Nossos resultados confirmaram que a PET/CT FDG é uma ferramenta útil na localização da zona epileptogênica e a monitoração com EEG é muito importante para correlacionar os achados. Além disso, PET/CT FDG realizada no período pós-ictal é capaz de identificar a zona epileptogênica, mostrando tanto hipometabolismo como hipermetabolismo.

Interictal and postictal 18F-FDG PET/CT in epileptogenic zone localization / PET/CT FDG- 18F interictal e pós-ictal na localização da zona epileptogênica

Abstract Objective: To evaluate the performance of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography ( 18F-FDG PET/CT) in localizing epileptogenic zones, comparing 18F-FDG injection performed in the traditional interictal period with that performed near the time of a seizure. Materials and Methods: We evaluated patients with refractory epilepsy who underwent 18F-FDG PET/CT. The reference standards for localization of the epileptogenic zone were histopathology and follow-up examinations (in patients who underwent surgery) or serial electroencephalography (EEG) recordings, long-term video EEG, and magnetic resonance imaging (in patients who did not). The 18F-FDG injection was performed whether the patient had an epileptic seizure during the EEG monitoring period or not. The 18F-FDG PET/CT results were categorized as concordant or discordant with the reference standards. Results: Of the 110 patients evaluated, 10 were in a postictal group (FDG injection after a seizure) and 100 were in the interictal group. The 18F-FDG PET/CT was concordant with the reference standards in nine (90%) of the postictal group patients and in 60 (60%) of the interictal group patients. Among the nine postictal group patients in whom the results were concordant, the 18F-FDG PET/CT showed hypermetabolism and hypometabolism in the epileptogenic zone in four (44.4%) and five (55.6%), respectively. Conclusion: Our data indicate that 18F-FDG PET/CT is a helpful tool for localization of the epileptogenic zone and that EEG monitoring is an important means of correlating the findings. In addition, postictal 18F-FDG PET/CT is able to identify the epileptogenic zone by showing either hypometabolism or hypermetabolism.

Resumo Objetivo: Avaliar a capacidade da PET/CT FDG detectar a zona epileptogênica, com injeção da FDG realizada tanto no período interictal como perto de uma crise epiléptica. Materiais e Métodos: Foram avaliados pacientes com epilepsia de difícil controle que realizaram PET/CT FDG. A zona epileptogênica foi definida pelo follow up/anatomopatológico ou eletroencefalogramas (EEGs) seriados, telemetria e ressonância magnética. PET/CT FDG foi realizada independentemente se o paciente tinha crise epiléptica durante a monitoração com EEG ou no período interictal. Os resultados foram definidos como concordantes ou discordantes, comparando com a zona epileptogênica. Resultados: Foram incluídos no estudo 110 pacientes: 10 no grupo pós-ictal (injeção de FDG depois da crise) e 100 no grupo interictal. A PET/CT FDG foi concordante com a zona epileptogênica em nove pacientes do grupo pós-ictal (90%) e 60 pacientes do grupo interictal (60%). Entre os nove pacientes concordantes do grupo pós-ictal, quatro mostraram hipermetabolismo (44,4%) e cinco mostraram hipometabolismo na zona epileptogênica (55,6%). Conclusão: Nossos resultados confirmaram que a PET/CT FDG é uma ferramenta útil na localização da zona epileptogênica e a monitoração com EEG é muito importante para correlacionar os achados. Além disso, PET/CT FDG realizada no período pós-ictal é capaz de identificar a zona epileptogênica, mostrando tanto hipometabolismo como hipermetabolismo.

Discriminating Aging Cognitive Decline Spectrum Using PET and Magnetic Resonance Image Features.

BACKGROUND: The population aging increased the prevalence of brain diseases, like Alzheimer's disease (AD). Early identification of individuals with higher odds of cognitive decline is essential to maintain quality of life. Imaging evaluation of individuals at risk of cognitive decline includes biomarkers extracted from brain positron emission tomography (PET) and structural magnetic resonance imaging (MRI). OBJECTIVE: We propose investigating ensemble models to classify groups in the aging cognitive decline spectrum by combining features extracted from single imaging modalities and combinations of imaging modalities (FDG+AMY+MRI, and a PET ensemble). METHODS: We group imaging data of 131 individuals into four classes related to the individuals' cognitive assessment in baseline and follow-up: stable cognitive non-impaired; individuals converting to mild cognitive impairment (MCI) syndrome; stable MCI; and Alzheimer's clinical syndrome. We assess the performance of four algorithms using leave-one-out cross-validation: decision tree classifier, random forest (RF), light gradient boosting machine (LGBM), and categorical boosting (CAT). The performance analysis of models is evaluated using balanced accuracy before and after using Shapley Additive exPlanations with recursive feature elimination (SHAP-RFECV) method. RESULTS: Our results show that feature selection with CAT or RF algorithms have the best overall performance in discriminating early cognitive decline spectrum mainly using MRI imaging features. CONCLUSION: Use of CAT or RF algorithms with SHAP-RFECV shows good discrimination of early stages of aging cognitive decline, mainly using MRI image features. Further work is required to analyze the impact of selected brain regions and their correlation with cognitive decline spectrum.

Brown fat triglyceride content is associated with cardiovascular risk markers in adults from a tropical region.

Brown adipose tissue (BAT) is regarded as an interesting potential target for the treatment of obesity, diabetes, and cardiovascular diseases, and the detailed characterization of its structural and functional phenotype could enable an advance in these fields. Most studies evaluating BAT structure and function were performed in temperate climate regions, and we are yet to know how these findings apply to the 40% of the world's population living in tropical areas. Here, we used 18F-fluorodeoxyglucose positron emission tomography - magnetic resonance imaging to evaluate BAT in 45 lean, overweight, and obese volunteers living in a tropical area in Southeast Brazil. We aimed at investigating the associations between BAT activity, volume, metabolic activity, and BAT content of triglycerides with adiposity and cardiovascular risk markers in a sample of adults living in a tropical area and we showed that BAT glucose uptake is not correlated with leanness; instead, BAT triglyceride content is correlated with visceral adiposity and markers of cardiovascular risk. This study expands knowledge regarding the structure and function of BAT in people living in tropical areas. In addition, we provide evidence that BAT triglyceride content could be an interesting marker of cardiovascular risk.

[18 F]FDG brain uptake of C57Bl/6 male mice is affected by locomotor activity after cocaine use: A small animal positron emission tomography study.

We verified if cocaine-induced peripheral activation might disrupt [18 F]FDG brain uptake after a cocaine challenge and suggested an optimal protocol to measure cocaine-induced brain metabolic alterations in mice. C57Bl/6 male mice were injected with [18 F]FDG and randomly separated into three groups. Groups 1 and 2 were kept conscious after [18 F]FDG administration and after 5 min received saline or cocaine (20 mg/kg). The animals in group 1 (n = 5) were then evaluated in the open field for 30 min and those from group 2 (n = 6) were kept alone in a home cage for the same period. Forty-five minutes after [18 F]FDG administration, images were acquired for 30 min. Group 3 (n = 6) was kept anesthetized and image acquisition started immediately after tracer injection, for 75 min. Saline (Day 1) or cocaine (Day 2) was injected 5 min after starting acquisition. Another set of animals (n = 5) were treated with cocaine every other day for 10 days or saline (n = 6) and were scanned with the dynamic protocol to verify its efficacy. [18 F]FDG uptake increased after cocaine administration when compared to baseline only in animals kept under anesthesia. No brain effect of cocaine was observed in animals submitted to the open field or kept in the home cage. The use of anesthesia is essential to visualize cocaine-induced changes in brain metabolism by [18 F]FDG PET, providing an interesting preclinical approach to investigate naïve subjects and enabling a bidirectional translational science approach for better understanding of cocaine use disorder.

Aportes de la tomografía por emisión de positrones con 18F-fluorodesoxiglucosa/tomografía computada en el diagnóstico de compromiso extramedular por mieloma múltiple en Uruguay / 18F-fluorodesoxyglucose positron emission tomography/computed tomography in extramedullary multiple myeloma

BACKGROUND: 18F-fluorodesoxyglucose positron emission tomography/ computed tomography (PET-CT) has a high sensitivity and specificity to detect medullary and extramedullary lesions in multiple myeloma (MM). AIM: To describe the findings of PET-CT in extramedullary multiple myeloma (EMM) at diagnosis and at relapse, and correlate its results with clinical variables, response to treatment and survival. MATERIALS AND METHODS: Review of medical records and PET-CT reports of 39 patients with multiple myeloma (MM) who had at least one PET-CT study, treated between January 1, 2015, and January 1, 2019 at a clinical hospital. RESULTS: The Standard Uptake Values for each hypermetabolic lesion were not described in PET-CT reports. Fifteen patients had an EMM and in eight, without a previous clinical suspicion, PET-TC lead to the diagnosis. The mortality rate in the 39 patients with MM was 46%. Sixty seven percent of deaths occurred in patients with EMM. CONCLUSIONS: PET-TC was useful to diagnose EMM. However, a standardization in PETCT reports would be required to unify criteria. As previously reported, EMM had a greater aggressiveness and lower survival.

Multimodality Molecular Imaging in Arthropathy Associated with Multiple Myeloma.

We report a patient with multiple myeloma (MM) and polyarthritis of large joints. During the staging of the disease, bone marrow diffusely involved by MM was clearly demonstrated by 99mTc-2-methoxy-isobutyl-isonitrile (MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) but not by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/CT images. On the other hand, a very intense uptake of 18F-FDG was detected in periarticular tissues of multiple joints, with nonabnormal 99mTc-MIBI accumulation. Rheumatology tests were negative. A subsequent bone scintigraphy demonstrated radiolabeled bisphosphonate accumulation in periarticular tissues, suggesting amyloid arthropathy.

Value of Primary Rectal Tumor PET/MRI in the Prediction of Synchronic Metastatic Disease.

PURPOSE: To analyze the associations between positron emission tomography (PET)/magnetic resonance imaging (MRI) features for primary rectal tumors and metastases. PROCEDURES: Between November 2016 and April 2018, 101 patients with rectal adenocarcinoma were included in this prospective study (NCT02537340) for whole-body PET/MRI for baseline staging. Two readers analyzed the PET/MRI; they assessed the semiquantitative PET features of the primary tumor and the N- and M-stages. Another reader analyzed the MRI features for locoregional staging. The reference standard for confirming metastatic disease was biopsy or imaging follow-up. Non-parametric tests were used to compare the PET/MRI features of the participants with or without metastatic disease. Binary logistic regression was used to evaluate the associations between the primary tumor PET/MRI features and metastatic disease. RESULTS: A total of 101 consecutive participants (median age 62 years; range: 33-87 years) were included. Metastases were detected in 35.6% (36 of 101) of the participants. Among the PET/MRI features, higher tumor lesion glycolysis (352.95 vs 242.70; P = .46) and metabolic tumor volume (36.15 vs 26.20; P = .03) were more frequent in patients with than in those without metastases. Additionally, patients with metastases had a higher incidence of PET-positive (64% vs 32%; P = .009) and MRI-positive (56% vs 32%; P = .03) mesorectal lymph nodes, extramural vascular invasion (86% vs 49%; P > .001), and involvement of mesorectal fascia (64% vs 42%; P = .04); there were also differences between the mrT stages of these two groups (P = .008). No differences in the maximum standardized uptake values for the primary tumors in patients with and without metastases were observed (18.9 vs 19.1; P = .56). Multivariable logistic regression showed that extramural vascular invasion on MRI was the only significant predictor (adjusted odds ratio, 3.8 [95% CI: 1.1, 13.9]; P = .001). CONCLUSION: PET/MRI facilitated the identification of participants with a high risk of metastatic disease, though these findings were based mainly on MRI features.

Metabolic Volume Measurements in Multiple Myeloma.

Multiple myeloma (MM) accounts for 10-15% of all hematologic malignancies, as well as 20% of deaths related to hematologic malignant tumors, predominantly affecting bone and bone marrow. Positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (FDG-PET/CT) is an important method to assess the tumor burden of these patients. It is often challenging to classify the extent of disease involvement in the PET scans for many of these patients because both focal and diffuse bone lesions may coexist, with varying degrees of FDG uptake. Different metrics involving volumetric parameters and texture features have been proposed to objectively assess these images. Here, we review some metabolic parameters that can be extracted from FDG-PET/CT images of MM patients, including technical aspects and predicting MM outcome impact. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are volumetric parameters known to be independent predictors of MM outcome. However, they have not been adopted in clinical practice due to the lack of measuring standards. CT-based segmentation allows automated, and therefore reproducible, calculation of bone metabolic metrics in patients with MM, such as maximum, mean and standard deviation of the standardized uptake values (SUV) for the entire skeleton. Intensity of bone involvement (IBI) is a new parameter that also takes advantage of this approach with promising results. Other indirect parameters obtained from FDG-PET/CT images, such as visceral adipose tissue glucose uptake and subcutaneous adipose tissue radiodensity, may also be useful to evaluate the prognosis of MM patients. Furthermore, the use and quantification of new radiotracers can address different metabolic aspects of MM and may have important prognostic implications.

The ratio between the whole-body and primary tumor burden, measured on 18F-FDG PET/CT studies, as a prognostic indicator in advanced non-small cell lung cancer.

OBJECTIVE: To determine whether the whole-body tumor burden, as quantified by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT), is a prognostic indicator in advanced (stage III or IV) non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: This was a prospective study in which we evaluated 18F-FDG PET/CT staging parameters to quantify tumor burdens in patients with stage III or IV NSCLC. The following parameters were evaluated for the whole body (including the primary tumor) and for the primary tumor alone, respectively: maximum standardized uptake volume (wbSUVmax and tuSUVmax); metabolic tumor volume (wbMTV and tuMTV); and total lesion glycolysis (wbTLG and tuTLG). To determine whether the 18F-FDG PET/CT parameters were associated with overall survival (OS) and progression-free survival (PFS), we evaluated the wbSUVmax/tuSUVmax, wbMTV/tuMTV, and wbTLG/tuTLG ratios. RESULTS: 18F-FDG PET/CT was performed for staging in 52 patients who were followed for a median of 11.0 months (mean, 11.7 months). The estimated median PFS and OS were 9.6 months and 11.6 months, respectively. In the univariate analysis, OS was found to correlate significantly with wbTLG (hazard ratio [HR] = 1.001; 95% confidence interval [95 CI]: 1.000-1.001; p = 0.0361) and with the wbTLG/tuTLG ratio (HR = 1.705; 95% CI: 1.232-2.362; p = 0.0013). In the multivariate analysis, only the wbTLG/tuTLG ratio was independently associated with OS (HR = 1.660; 95% CI: 1.193-2.310; p = 0.0027). CONCLUSION: The wbTLG/tuTLG ratio is an independent prognostic indicator of OS in advanced-stage NSCLC.

OBJETIVO: Avaliar se a carga metabólica tumoral do corpo inteiro medida na tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose (18F-FDG PET/CT) é um indicador prognóstico em pacientes com câncer de pulmão de células não pequenas (CPCNP) em estágio avançado (estágio III ou IV). MATERIAIS E MÉTODOS: Avaliamos, prospectivamente, a carga tumoral na 18F-FDG-PET/CT de estadiamento em pacientes com CPCNP avançado. Os parâmetros avaliados do tumor primário (tu) e do corpo inteiro (wb) (incluindo o primário) foram: SUV máximo (wbSUVmax e tuSUVmax), volume metabólico tumoral (wbMTV e tuMTV), glicólise total da(s) lesão(ões) (wbTLG e tuTLG), além das seguintes razões: wbSUVmax/tuSUVmax, wbMTV/tuMTV e wbTLG/tuTLG. Os parâmetros medidos na 18F-FDG-PET/CT, variáveis clínicas e patológicas foram correlacionados com a sobrevida global (SG) e a sobrevida livre de progressão (SLP). RESULTADOS: 18F-FDG-PET/CT foi realizada em 52 pacientes (tempos mediano/médio de sobrevida = 11,0/11,7 meses). A SLP mediana foi de 9,6 meses e a SG foi de 11,6 meses. Houve correlação significativa da wbTLG (hazard ratio [HR] = 1,001; intervalo de confiança de 95% [IC 95%]: 1,000-1,001; p = 0,0361) e wbTLG/tuTLG (HR = 1,705; IC 95%: 1,232-2.362; p = 0,0013) com a SG. Na análise multivariada, a razão wbTLG/tuTLG associou-se independentemente com a SG (HR = 1,660; IC 95%: 1,193-2,310; p = 0,0027). CONCLUSÃO: A razão wbTLG/tuTLG é um indicador prognóstico independente de SG em CPCNP avançado.

The ratio between the whole-body and primary tumor burden, measured on 18F-FDG PET/CT studies, as a prognostic indicator in advanced non-small cell lung cancer / A relação entre a carga de doença de corpo inteiro e lesão primária medida em estudos de 18F-FDG PET/CT como um indicador prognóstico em câncer de pulmão não pequenas células avançado

Abstract Objective: To determine whether the whole-body tumor burden, as quantified by 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT), is a prognostic indicator in advanced (stage III or IV) non-small cell lung cancer (NSCLC). Materials and Methods: This was a prospective study in which we evaluated 18F-FDG PET/CT staging parameters to quantify tumor burdens in patients with stage III or IV NSCLC. The following parameters were evaluated for the whole body (including the primary tumor) and for the primary tumor alone, respectively: maximum standardized uptake volume (wbSUVmax and tuSUVmax); metabolic tumor volume (wbMTV and tuMTV); and total lesion glycolysis (wbTLG and tuTLG). To determine whether the 18F-FDG PET/CT parameters were associated with overall survival (OS) and progression-free survival (PFS), we evaluated the wbSUVmax/tuSUVmax, wbMTV/tuMTV, and wbTLG/tuTLG ratios. Results: 18F-FDG PET/CT was performed for staging in 52 patients who were followed for a median of 11.0 months (mean, 11.7 months). The estimated median PFS and OS were 9.6 months and 11.6 months, respectively. In the univariate analysis, OS was found to correlate significantly with wbTLG (hazard ratio [HR] = 1.001; 95% confidence interval [95 CI]: 1.000-1.001; p = 0.0361) and with the wbTLG/tuTLG ratio (HR = 1.705; 95% CI: 1.232-2.362; p = 0.0013). In the multivariate analysis, only the wbTLG/tuTLG ratio was independently associated with OS (HR = 1.660; 95% CI: 1.193-2.310; p = 0.0027). Conclusion: The wbTLG/tuTLG ratio is an independent prognostic indicator of OS in advanced-stage NSCLC.

Resumo Objetivo: Avaliar se a carga metabólica tumoral do corpo inteiro medida na tomografia por emissão de pósitrons/tomografia computadorizada com 18F-fluordesoxiglicose (18F-FDG PET/CT) é um indicador prognóstico em pacientes com câncer de pulmão de células não pequenas (CPCNP) em estágio avançado (estágio III ou IV). Materiais e Métodos: Avaliamos, prospectivamente, a carga tumoral na 18F-FDG-PET/CT de estadiamento em pacientes com CPCNP avançado. Os parâmetros avaliados do tumor primário (tu) e do corpo inteiro (wb) (incluindo o primário) foram: SUV máximo (wbSUVmax e tuSUVmax), volume metabólico tumoral (wbMTV e tuMTV), glicólise total da(s) lesão(ões) (wbTLG e tuTLG), além das seguintes razões: wbSUVmax/tuSUVmax, wbMTV/tuMTV e wbTLG/tuTLG. Os parâmetros medidos na 18F-FDG-PET/CT, variáveis clínicas e patológicas foram correlacionados com a sobrevida global (SG) e a sobrevida livre de progressão (SLP). Resultados: 18F-FDG-PET/CT foi realizada em 52 pacientes (tempos mediano/médio de sobrevida = 11,0/11,7 meses). A SLP mediana foi de 9,6 meses e a SG foi de 11,6 meses. Houve correlação significativa da wbTLG (hazard ratio [HR] = 1,001; intervalo de confiança de 95% [IC 95%]: 1,000-1,001; p = 0,0361) e wbTLG/tuTLG (HR = 1,705; IC 95%: 1,232-2.362; p = 0,0013) com a SG. Na análise multivariada, a razão wbTLG/tuTLG associou-se independentemente com a SG (HR = 1,660; IC 95%: 1,193-2,310; p = 0,0027). Conclusão: A razão wbTLG/tuTLG é um indicador prognóstico independente de SG em CPCNP avançado.

Metabolic and Structural Signatures of Speech and Language Impairment in Corticobasal Syndrome: A Multimodal PET/MRI Study.

Introduction: Corticobasal syndrome (CBS) is a progressive neurological disorder related to multiple underlying pathologies, including four-repeat tauopathies, such as corticobasal degeneration and progressive supranuclear palsy, and Alzheimer's disease (AD). Speech and language are commonly impaired, encompassing a broad spectrum of deficits. We aimed to investigate CBS speech and language impairment patterns in light of a multimodal imaging approach. Materials and Methods: Thirty-one patients with probable CBS were prospectively evaluated concerning their speech-language, cognitive, and motor profiles. They underwent positron emission tomography with [18F]fluorodeoxyglucose (FDG-PET) and [11C]Pittsburgh Compound-B (PIB-PET) on a hybrid PET-MRI machine to assess their amyloid status. PIB-PET images were classified based on visual and semi-quantitative analyses. Quantitative group analyses were performed on FDG-PET data, and atrophy patterns on MRI were investigated using voxel-based morphometry (VBM). Thirty healthy participants were recruited as imaging controls. Results: Aphasia was the second most prominent cognitive impairment, presented in 67.7% of the cases, following apraxia (96.8%). We identified a wide linguistic profile, ranging from nonfluent variant-primary progressive aphasia to lexical-semantic deficits, mostly with impaired verbal fluency. PIB-PET was classified as negative (CBS-A- group) in 18/31 (58%) and positive (CBS-A+ group) in 13/31 (42%) patients. The frequency of dysarthria was significantly higher in the CBS-A- group than in the CBS-A+ group (55.6 vs. 7.7%, p = 0.008). CBS patients with dysarthria had a left-sided hypometabolism at frontal regions, with a major cluster at the left inferior frontal gyrus and premotor cortex. They showed brain atrophy mainly at the opercular frontal gyrus and putamen. There was a positive correlation between [18F]FDG uptake and semantic verbal fluency at the left inferior (p = 0.006, R 2 = 0.2326), middle (0.0054, R 2 = 0.2376), and superior temporal gyri (p = 0.0066, R 2 = 0.2276). Relative to the phonemic verbal fluency, we found a positive correlation at the left frontal opercular gyrus (p = 0.0003, R 2 = 0.3685), the inferior (p = 0.0004, R 2 = 0.3537), and the middle temporal gyri (p = 0.0001, R 2 = 0.3993). Discussion: In the spectrum of language impairment profile, dysarthria might be helpful to distinguish CBS patients not related to AD. Metabolic and structural signatures depicted from this feature provide further insights into the motor speech production network and are also helpful to differentiate CBS variants.

Oncological Follow-up with 2-[18F]-FDG PET/CT in Li-Fraumeni Syndrome

Li-Fraumeni syndrome is a rare disorder caused by abnormalities of the tumor-suppressor protein P53 gene. We present the case of a 26-years-old female diagnosed with bilateral ductal carcinoma. The genetic panel for breast cancer gene 1 (BRCA1) and BRCA2 mutations was negative and positive heterozygous germline tumor protein P53 gene mutations, considering Li-Fraumeni syndrome. A 2-[18F]-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) was used for postsurgical staging to show the right lung hypermetabolic nodule. A lobectomy was accomplished, and histopathology reported pulmonary adenocarcinoma. A year later, oncological follow-up was conducted with 2-[18F]-FDG PET/CT without evidence of abnormalities.

18f-Fluorodeoxyglucose Positron Emission Tomography Versus Bone Marrow Biopsy for the Evaluation of Bone Marrow Infiltration in Newly Diagnosed Lymphoma Patients

ABSTRACT Background: Bone marrow evaluation (BME) is crucial for establishing an accurate staging and prognosis in lymphoma patients. Objective: The objective of the study was to study the diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) against bone marrow biopsy (BMB) for BME. Methods: Five hundred patient files of newly diagnosed lymphoma patients treated at an academic medical center were reviewed for BME at diagnosis by BMB and FDG PET-CT. Diagnostic performance of FDG PET-CT for detecting bone marrow infiltration (BMI) was assessed, as well as clinical predictors for positive BMB and positive FDG PET-CT. Results: BMB was positive in 16.3% of all patients, and 28.7% had a positive FDG PET-CT for BMI. Overall, the sensitivity of FDG PET-CT was 74.1% and specificity 80.1%. As for predictors for BMB and FDG PET-CT positivity, B symptoms and thrombocytopenia were independent factors for BMI. Seventy-four patients had discordant results between BMB and FDG PET-CT, non-Hodgkin lymphoma (NHL) having the most significant discordance. This discrepancy did not affect treatment. Conclusions: FDG PET-CT shows excellent performance for the detection of BMI in Hodgkin lymphoma. For diffuse large B-cell lymphoma, we recommend performing BMB and FDG PET-CT as complementary tests. In all other NHL, a unilateral BMB is mandatory at diagnosis.

Diagnostic accuracy of FDG-PET/MRI versus pelvic MRI and thoracic and abdominal CT for detecting synchronous distant metastases in rectal cancer patients.

PURPOSE: We compared the diagnostic accuracy of detecting distant metastases for baseline rectal cancer staging between PET/MRI and conventional staging (CS). MATERIALS AND METHODS: This prospective study from November 2016 to April 2018 included 101 rectal adenocarcinoma patients for primary staging. These patients underwent whole-body PET/MRI in addition to CS (pelvic MRI and thoracic and abdominal contrast-enhanced CT). Different readers analyzed CS and PET/MRI findings for primary tumor, nodal, and metastatic staging. The presence, number, and location of metastases were recorded according to the organ involved (non-regional lymph nodes (LNs), liver, lungs, or others). Lesions were defined as positive, negative, or indeterminate. The number of lesions per organ was limited to 10. The McNemar test was used to compare the accuracies. RESULTS: PET/MRI exhibited a higher accuracy in detecting metastatic disease than CS in all patients (88.4% vs. 82.6%, p = 0.003) and in patients with extramural vascular invasion (EMVI) (88.9% vs. 85.5%, p = 0.013). The detection rate of PET/MRI was superior to that of CS for all lesions [84.1% vs. 68.9%, p = 0.001], as well as those in the liver (89.2% vs. 84.2%), non-regional LNs (90.0% vs. 36.7%), and lungs (76.4% vs. 66.9%). PET/MRI correctly classified 19/33 (57.5%) patients with indeterminate lesions on CS. CONCLUSION: PET/MRI yields higher accuracy than CS for detecting distant synchronous metastases in the baseline staging of patients with rectal cancer and EMVI. PET/MRI exhibited a higher detection rate than CS for identifying non-regional LNs, hepatic lesions, and pulmonary lesions as well as correctly classifying patients with indeterminate lesions. TRIAL REGISTRATION: NCT02537340.

FDG-PET Patterns Predict Amyloid Deposition and Clinical Profile in Corticobasal Syndrome.

BACKGROUND: Corticobasal syndrome (CBS) is an atypical parkinsonian syndrome related to multiple underlying pathologies. OBJECTIVE: To investigate if individual brain [18 F]fluorodeoxyglucose-positron emission tomography (FDG-PET) patterns could distinguish CBS due to Alzheimer's disease (AD) from other pathologies based on [11 C]Pittsburgh Compound-B (PIB)-PET. METHODS: Forty-five patients with probable CBS were prospectively evaluated regarding cognitive and movement disorders profile. They underwent FDG-PET and were distributed into groups: likely related to AD (CBS FDG-AD) or likely non-AD (CBS FDG-nonAD) pathology. Thirty patients underwent PIB-PET on a hybrid PET-magnetic resonance imaging equipment to assess their amyloid status. FDG and PIB-PET images were classified individually based on visual and semi-quantitative analysis, blinded to each other. Quantitative group analyses were also performed. RESULTS: CBS FDG-AD group demonstrated worse cognitive performances, mostly concerning attention, memory, visuospatial domains, and displayed more myoclonus and hallucinations. The non-AD metabolic group presented more often limb dystonia, ocular motor dysfunction, motor perseveration, and dysarthria. All patients classified as CBS FDG-AD tested positive at PIB-PET compared to 3 of 20 in the non-AD group. The individual FDG-PET classification demonstrated 76.92% of sensitivity, 100% of specificity and positive predictive value and 88.5% of balanced accuracy to detect positive PIB-PET scans. Individuals with positive and negative PIB-PET showed hypometabolism in posterior temporoparietal areas and in thalamus and brainstem, respectively, mainly contralateral to most affected side, disclosing possible metabolic signatures of CBS variants. CONCLUSION: FDG-PET was useful to predict AD and non-AD CBS variants depicting their specific degeneration patterns, different clinical features, and brain amyloid deposition. © 2020 International Parkinson and Movement Disorder Society.