Qual o valor da análise semi-quantitativa dos exames de FDG-PET no diagnóstico da esclerose mesial temporal?

O objetivo deste estudo foi comparar a análise visual dos exames de FDG-PET com uma análise semi-quantitativa no diagnóstico da esclerose mesial temporal (EMT). MÉTODOS: Este estudo incluiu 21 pacientes com confirmação histopatológica de EMT. Os dados referentes à análise visual foram obtidos dos relatórios dos exames. As imagens de FDG-PET foram analisadas de forma semi-quantitativa utilizando-se regiões de interesse (ROIs) desenhadas em 19 cortes tomográficos perpendiculares ao maior eixo do lobo temporal. Estas ROIs dividiram cada um dos lobos temporais em três regiões (lateral, inferior e medial). Um índice de assimetria foi calculado para cada região. RESULTADOS: A análise visual dos exames de FDG-PET demonstrou assimetria no metabolismo em todos os pacientes. Todos, menos 1 dos pacientes foram submetidos a lobectomia temporal do tipo standard do lado descrito como hipometabólico pelo exame de FDG-PET. Utilizando como critério um índice de assimetria maior ou igual a 9% em ao menos uma das regiões, a análise semi-quantitativa demonstrou assimetria considerada significativa em 18 pacientes. Esta assimetria coincidiu com o lado da cirurgia e foi confirmada como correspondente à área de eslerose em todos menos um dos pacientes (o mesmo paciente citado acima). CONCLUSÃO: A análise semi-quantitativa não forneceu qualquer informação adicional em relação à interpretação visual das imagens nesta série de pacientes

Quantitative evaluation of normal spinal osseous metabolism with ¹⁸F-NaF PET/CT

OBJECTIVE: The aim of this study was to describe osseous metabolic activity with respect to age and weight in the spine as expressed through fluorine-18-sodium fluoride (F-NaF) uptake in a healthy male population.PARTICIPANTS AND METHODS: Whole-body F-NaF PET/CT scans of healthy male participants (22-71 years, 50-145 kg, n=47) were analysed using a global assessment methodology to derive the mean standardized uptake values (SUVmean). Individual regions of the spine (cervical, thoracic and lumbar) along with the aggregate whole spine were assessed and compared as potential functions of age and body weight.RESULTS: Older participants did not have higher F-NaF uptake than younger participants (whole spine, P=0.93; cervical, P=0.12, thoracic, P=0.93; lumbar, P=0.42), whereas increasing body weight was associated with greater tracer uptake (whole spine P=0.003; cervical P=0.01; thoracic P=0.002; lumbar P=0.004). Both the thoracic (average SUVmean=4.864±1.338) and lumbar (average SUVmean=4.939±1.284) spines had significantly elevated (P≤0.0001) uptake compared with the cervical spine (average SUVmean=3.969±1.024).CONCLUSION: We assessed the metabolic activity of the spine's osseous tissues with F-NaF PET using a global assessment approach in healthy men. Our study provides evidence of differences in spinal metabolism as related to weight, but not age. Our study offers a foundation for future larger studies in symptomatic populations.</p

An update on the role of 18F-FDG-PET/CT in major infectious and inflammatory diseases

For decades, conventional nuclear medicine techniques have been utilized for the assessment of many infectious and inflammatory diseases. Most of these techniques have limitations such as the relatively low spatial resolution, being time consuming and low sensitivity or specificity. In recent years, FDG-PET/CT has shown promising role in the management of such diseases. An expanding set of studies illustrate the multifarious roles of FDG-PET/CT in the assessment of these conditions, both systemic diseases and more regional. Specifically, PET can provide vital information at a molecular level and consequently detect the disease activity at their earliest manifestation. With the continuing research on the diagnosis and treatment monitoring of patients with infectious and inflammatory diseases, the role of PET/CT can be further extended.</p

An update on the role of 18F-FDG-PET/CT in major infectious and inflammatory diseases

For decades, conventional nuclear medicine techniques have been utilized for the assessment of many infectious and inflammatory diseases. Most of these techniques have limitations such as the relatively low spatial resolution, being time consuming and low sensitivity or specificity. In recent years, FDG-PET/CT has shown promising role in the management of such diseases. An expanding set of studies illustrate the multifarious roles of FDG-PET/CT in the assessment of these conditions, both systemic diseases and more regional. Specifically, PET can provide vital information at a molecular level and consequently detect the disease activity at their earliest manifestation. With the continuing research on the diagnosis and treatment monitoring of patients with infectious and inflammatory diseases, the role of PET/CT can be further extended.</p

Prognostic significance of 18F-sodium fluoride in newly diagnosed multiple myeloma patients

Focal bone lesions and fractures due to weakened bone are associated with higher morbidity and mortality of multiple myeloma (MM) patients. 18F-sodium fluoride (18F-NaF) is a sensitive PET radiotracer for detection of abnormal bone metabolism and, therefore, is particularly suited to assess the degree of bone involvement in MM patients. We aimed to investigate the prognostic significance of metabolic active volume (MAV) of 18F-NaF-avid lesions in MM patients. In addition to MAV, conventional methods of PET quantification, namely SUVmean and SUVmax, were measured in each patient for the purpose of comparison. Thirty-seven newly diagnosed MM patients were included. PET imaging was performed after intravenous administration of 200 MBq NaF. Active bone lesions and fractures on whole-body 18F-NaF-PET/CT scans were identified. An adaptive thresholding algorithm automatically calculated the total MAV, SUVmean and SUVmax for each patient (ROVER, ABX, Radeberg, Germany). The patients were followed for a median of 39.8 months after treatment (range: 17.8-55.4). The overall survival (OS) of patients with 18F-NaF-MAV value &gt; 38.65 (36.36% [N of Events/Total N: 4/11]) was significantly shorter than that of patients with 18F-NaF-MAV value &lt; 38.65 (3.85% [1/26]; P = 0.002). In multivariate forward stepwise (conditional LR) Cox regression analysis of prognostic factors of OS (including 18F-NaF-MAV (&gt; 38.65 or &lt; 38.65), age, gender, beta-2 microglobulin, and revised international staging system), 18F-NaF-MAV remained the only significant factor (HR: 14.39, P = 0.02). The results for PFS were not significant. Moreover, Kaplan-Meier analyses of conventional methods of PET quantification did not reveal any statistically significant log-rank p-values. MM patients with high 18F-NaF-MAV had shorter overall survival, compared to those with low 18F-NaF-MAV levels (NCT02187731).</p

Prognostic significance of 18F-sodium fluoride in newly diagnosed multiple myeloma patients

Focal bone lesions and fractures due to weakened bone are associated with higher morbidity and mortality of multiple myeloma (MM) patients. 18F-sodium fluoride (18F-NaF) is a sensitive PET radiotracer for detection of abnormal bone metabolism and, therefore, is particularly suited to assess the degree of bone involvement in MM patients. We aimed to investigate the prognostic significance of metabolic active volume (MAV) of 18F-NaF-avid lesions in MM patients. In addition to MAV, conventional methods of PET quantification, namely SUVmean and SUVmax, were measured in each patient for the purpose of comparison. Thirty-seven newly diagnosed MM patients were included. PET imaging was performed after intravenous administration of 200 MBq NaF. Active bone lesions and fractures on whole-body 18F-NaF-PET/CT scans were identified. An adaptive thresholding algorithm automatically calculated the total MAV, SUVmean and SUVmax for each patient (ROVER, ABX, Radeberg, Germany). The patients were followed for a median of 39.8 months after treatment (range: 17.8-55.4). The overall survival (OS) of patients with 18F-NaF-MAV value &gt; 38.65 (36.36% [N of Events/Total N: 4/11]) was significantly shorter than that of patients with 18F-NaF-MAV value &lt; 38.65 (3.85% [1/26]; P = 0.002). In multivariate forward stepwise (conditional LR) Cox regression analysis of prognostic factors of OS (including 18F-NaF-MAV (&gt; 38.65 or &lt; 38.65), age, gender, beta-2 microglobulin, and revised international staging system), 18F-NaF-MAV remained the only significant factor (HR: 14.39, P = 0.02). The results for PFS were not significant. Moreover, Kaplan-Meier analyses of conventional methods of PET quantification did not reveal any statistically significant log-rank p-values. MM patients with high 18F-NaF-MAV had shorter overall survival, compared to those with low 18F-NaF-MAV levels (NCT02187731).</p

Prognostic significance of 18F-sodium fluoride in newly diagnosed multiple myeloma patients

Focal bone lesions and fractures due to weakened bone are associated with higher morbidity and mortality of multiple myeloma (MM) patients. 18F-sodium fluoride (18F-NaF) is a sensitive PET radiotracer for detection of abnormal bone metabolism and, therefore, is particularly suited to assess the degree of bone involvement in MM patients. We aimed to investigate the prognostic significance of metabolic active volume (MAV) of 18F-NaF-avid lesions in MM patients. In addition to MAV, conventional methods of PET quantification, namely SUVmean and SUVmax, were measured in each patient for the purpose of comparison. Thirty-seven newly diagnosed MM patients were included. PET imaging was performed after intravenous administration of 200 MBq NaF. Active bone lesions and fractures on whole-body 18F-NaF-PET/CT scans were identified. An adaptive thresholding algorithm automatically calculated the total MAV, SUVmean and SUVmax for each patient (ROVER, ABX, Radeberg, Germany). The patients were followed for a median of 39.8 months after treatment (range: 17.8-55.4). The overall survival (OS) of patients with 18F-NaF-MAV value &gt; 38.65 (36.36% [N of Events/Total N: 4/11]) was significantly shorter than that of patients with 18F-NaF-MAV value &lt; 38.65 (3.85% [1/26]; P = 0.002). In multivariate forward stepwise (conditional LR) Cox regression analysis of prognostic factors of OS (including 18F-NaF-MAV (&gt; 38.65 or &lt; 38.65), age, gender, beta-2 microglobulin, and revised international staging system), 18F-NaF-MAV remained the only significant factor (HR: 14.39, P = 0.02). The results for PFS were not significant. Moreover, Kaplan-Meier analyses of conventional methods of PET quantification did not reveal any statistically significant log-rank p-values. MM patients with high 18F-NaF-MAV had shorter overall survival, compared to those with low 18F-NaF-MAV levels (NCT02187731).</p

Correlation of whole-bone marrow dual-time-point 18F-FDG, as measured by a CT-based method of PET/CT quantification, with response to treatment in newly diagnosed multiple myeloma patients

The practical application of dual-time-point-imaging (DTPI) technique still remains controversial. One of the issues is that current parameters of DTPI quantification suffer from some deficiencies, mainly limited sampling of the diseased sites by confining measurements to specific locations. We aimed to examine the correlation between the percent change from early to delayed scans in whole-bone marrow (WBM) 18F-FDG uptake, as measured by a CT-based method of PET/CT quantification, and response to treatment in multiple myeloma (MM) patients. Pre-treatment 18F-FDG-PET/CT scans of 36 newly diagnosed MM patients were collected in a prospective study at 1 h and 3 h post tracer injection (NCT02187731). A threshold algorithm based on bone Hounsfield units on CT was applied to segment and quantify WBM 18F-FDG uptake. Patients were separated into two treatment groups: high-dose therapy with autologous stem cell transplant (HDT) and non-high dose therapy (non-HDT). The International Response Criteria for MM patients was used to determine each patient's response to treatment. In the HDT group, WBM 18F-FDG uptake increased significantly in patients that had a poor response to treatment, from a median of 1.31 (IQR: 1.13-1.64) at 1 h to a median of 1.85 (1.45-2.10) at 3 h. The median percent change was 37.77% (IQR: 23.47-46.4), with a range of 6.10-50.73 (P = 0.003). However, no significant change in uptake was observed in patients with a complete response (P = 0.24). The same trend was observed for the non-HDT group. WBM uptake of 18F-FDG assessed with dual-time-point imaging may have a role in predicting treatment response in MM.</p

Correlation of whole-bone marrow dual-time-point 18F-FDG, as measured by a CT-based method of PET/CT quantification, with response to treatment in newly diagnosed multiple myeloma patients

The practical application of dual-time-point-imaging (DTPI) technique still remains controversial. One of the issues is that current parameters of DTPI quantification suffer from some deficiencies, mainly limited sampling of the diseased sites by confining measurements to specific locations. We aimed to examine the correlation between the percent change from early to delayed scans in whole-bone marrow (WBM) 18F-FDG uptake, as measured by a CT-based method of PET/CT quantification, and response to treatment in multiple myeloma (MM) patients. Pre-treatment 18F-FDG-PET/CT scans of 36 newly diagnosed MM patients were collected in a prospective study at 1 h and 3 h post tracer injection (NCT02187731). A threshold algorithm based on bone Hounsfield units on CT was applied to segment and quantify WBM 18F-FDG uptake. Patients were separated into two treatment groups: high-dose therapy with autologous stem cell transplant (HDT) and non-high dose therapy (non-HDT). The International Response Criteria for MM patients was used to determine each patient's response to treatment. In the HDT group, WBM 18F-FDG uptake increased significantly in patients that had a poor response to treatment, from a median of 1.31 (IQR: 1.13-1.64) at 1 h to a median of 1.85 (1.45-2.10) at 3 h. The median percent change was 37.77% (IQR: 23.47-46.4), with a range of 6.10-50.73 (P = 0.003). However, no significant change in uptake was observed in patients with a complete response (P = 0.24). The same trend was observed for the non-HDT group. WBM uptake of 18F-FDG assessed with dual-time-point imaging may have a role in predicting treatment response in MM.</p

Correlation of whole-bone marrow dual-time-point 18F-FDG, as measured by a CT-based method of PET/CT quantification, with response to treatment in newly diagnosed multiple myeloma patients

The practical application of dual-time-point-imaging (DTPI) technique still remains controversial. One of the issues is that current parameters of DTPI quantification suffer from some deficiencies, mainly limited sampling of the diseased sites by confining measurements to specific locations. We aimed to examine the correlation between the percent change from early to delayed scans in whole-bone marrow (WBM) 18F-FDG uptake, as measured by a CT-based method of PET/CT quantification, and response to treatment in multiple myeloma (MM) patients. Pre-treatment 18F-FDG-PET/CT scans of 36 newly diagnosed MM patients were collected in a prospective study at 1 h and 3 h post tracer injection (NCT02187731). A threshold algorithm based on bone Hounsfield units on CT was applied to segment and quantify WBM 18F-FDG uptake. Patients were separated into two treatment groups: high-dose therapy with autologous stem cell transplant (HDT) and non-high dose therapy (non-HDT). The International Response Criteria for MM patients was used to determine each patient's response to treatment. In the HDT group, WBM 18F-FDG uptake increased significantly in patients that had a poor response to treatment, from a median of 1.31 (IQR: 1.13-1.64) at 1 h to a median of 1.85 (1.45-2.10) at 3 h. The median percent change was 37.77% (IQR: 23.47-46.4), with a range of 6.10-50.73 (P = 0.003). However, no significant change in uptake was observed in patients with a complete response (P = 0.24). The same trend was observed for the non-HDT group. WBM uptake of 18F-FDG assessed with dual-time-point imaging may have a role in predicting treatment response in MM.</p