Assessment of pulmonary 18 F-FDG-PET uptake and cytokine profiles in non-small cell lung cancer patients treated with radiotherapy and erlotinib

Purpose: To investigate effects of radiotherapy (RT) and erlotinib on pulmonary glucose uptake using 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography (PET) during and after treatment of non-small cell lung cancer (NSCLC) and to identify associations between serum cytokine levels and lung glucose uptake. Material and methods: Twenty-seven patients with advanced NSCLC, receiving RT alone or concomitant RT and erlotinib therapy, were examined by 18F-FDG PET before, during, and after treatment. A total of 57 18F-FDG PET scans were analyzed. Pulmonary 18F-FDG uptake and radiotherapy dose mapping were used to acquire dose-response curves for each patient, where subsequent linear regression gave a glucose uptake level in the un-irradiated parts of the lungs (SUV0) and a response slope (ΔSUV). Serum cytokine levels at corresponding time points were assessed using a multiplex bioassay. Correlations between the most robust cytokines and lung 18F-FDG dose response parameters were further investigated. Results: From the dose response analysis, SUV0 at post-therapy was significantly higher (P < 0.001) than at mid- and pre-therapy (45% and 58%, respectively) for the group receiving RT + erlotinib. Also, SUV0 at post-therapy was higher for patients receiving RT + erlotinib compared to RT alone (42%; P < 0.001). No differences in ΔSUV were seen with treatments or time. SUV0 was positively associated (r = 0.47, P = 0.01) with serum levels of the chemokine C–C motif ligand 21 (CCL21) for patients receiving RT + erlotinib. Conclusions: Concomitant RT and erlotinib causes an elevation in pulmonary 18F-FDG uptake post treatment compared to RT alone. Pulmonary glucose uptake is associated with an upregulation of a chemokine (CCL21) involved in inflammatory reactions

A new method to assess pulmonary changes using (18)F-fluoro-2-deoxyglucose positron emission tomography for lung cancer patients following radiotherapy

BACKGROUND: (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG-PET) may be used for assessing radiation induced alterations in the lung. However, there is a need to further develop methodologies to improve quantification. Using computed tomography (CT), a local structure method has been shown to be superior to conventional CT-based analysis. Here, we investigate whether the local structure method based on (18)F-FDG-PET improves radiotherapy (RT) dose-response quantification for lung cancer patients. MATERIAL AND METHODS: Sixteen patients with lung cancer undergoing fractionated RT were examined by (18)F-FDG-PET/CT at three sessions (pre, mid, post) and the lung was delineated in the planning CT images. The RT dose matrix was co-registered with the PET images. For each PET image series, mean (μ) and standard deviation (σ) maps were calculated based on cubes in the lung (3 × 3 × 3 voxels), where the spread in pre-therapy μ and σ was characterized by a covariance ellipse in a sub-volume of 3 × 3 × 3 cubes. Mahalanobis distance was used to measure the distance of individual cube values to the origin of the ellipse and to further form local structure 'S' maps. The structural difference maps (ΔS) and mean difference maps (Δμ) were calculated by subtracting pre-therapy maps from maps at mid- and post-therapy. Corresponding maps based on CT images were also generated. RESULTS: ΔS identified new areas of interest in the lung compared to conventional Δμ maps. ΔS for PET and CT gave a significantly elevated lung signal compared to a control group during and post-RT (p < .05). Dose-response analyses by linear regression showed that ΔS between pre- and post-therapy for (18)F-FDG-PET was the only parameter significantly associated with local lung dose (p = .04). CONCLUSIONS: The new method using local structures on (18)F-FDG-PET provides a clearer uptake dose-response compared to conventional analysis and CT-based approaches and may be valuable in future studies addressing lung toxicity

A new method to assess pulmonary changes using ¹⁸F-fluoro-2-deoxyglucose positron emission tomography for lung cancer patients following radiotherapy

<p><b>Background:</b>¹⁸F-fluoro-2-deoxyglucose positron emission tomography (¹⁸F-FDG-PET) may be used for assessing radiation induced alterations in the lung. However, there is a need to further develop methodologies to improve quantification. Using computed tomography (CT), a local structure method has been shown to be superior to conventional CT-based analysis. Here, we investigate whether the local structure method based on ¹⁸F-FDG-PET improves radiotherapy (RT) dose–response quantification for lung cancer patients.</p> <p><b>Material and methods:</b> Sixteen patients with lung cancer undergoing fractionated RT were examined by ¹⁸F-FDG-PET/CT at three sessions (pre, mid, post) and the lung was delineated in the planning CT images. The RT dose matrix was co-registered with the PET images. For each PET image series, mean (μ) and standard deviation (<i>σ</i>) maps were calculated based on cubes in the lung (3 × 3 × 3 voxels), where the spread in pre-therapy μ and <i>σ</i> was characterized by a covariance ellipse in a sub-volume of 3 × 3 × 3 cubes. Mahalanobis distance was used to measure the distance of individual cube values to the origin of the ellipse and to further form local structure ‘<i>S</i>’ maps. The structural difference maps (Δ<i>S</i>) and mean difference maps (Δμ) were calculated by subtracting pre-therapy maps from maps at mid- and post-therapy. Corresponding maps based on CT images were also generated.</p> <p><b>Results:</b> Δ<i>S</i> identified new areas of interest in the lung compared to conventional Δμ maps. Δ<i>S</i> for PET and CT gave a significantly elevated lung signal compared to a control group during and post-RT (<i>p</i> < .05). Dose–response analyses by linear regression showed that Δ<i>S</i> between pre- and post-therapy for ¹⁸F-FDG-PET was the only parameter significantly associated with local lung dose (<i>p</i> = .04).</p> <p><b>Conclusions:</b> The new method using local structures on ¹⁸F-FDG-PET provides a clearer uptake dose–response compared to conventional analysis and CT-based approaches and may be valuable in future studies addressing lung toxicity.</p

A new method to assess pulmonary changes using 18F-fluoro-2-deoxyglucose positron emission tomography for lung cancer patients following radiotherapy

Background:18F-fluoro-2-deoxyglucose positron emission tomography (18F-FDG-PET) may be used for assessing radiation induced alterations in the lung. However, there is a need to further develop methodologies to improve quantification. Using computed tomography (CT), a local structure method has been shown to be superior to conventional CT-based analysis. Here, we investigate whether the local structure method based on 18F-FDG-PET improves radiotherapy (RT) dose–response quantification for lung cancer patients. Material and methods: Sixteen patients with lung cancer undergoing fractionated RT were examined by 18F-FDG-PET/CT at three sessions (pre, mid, post) and the lung was delineated in the planning CT images. The RT dose matrix was co-registered with the PET images. For each PET image series, mean (μ) and standard deviation (σ) maps were calculated based on cubes in the lung (3 × 3 × 3 voxels), where the spread in pre-therapy μ and σ was characterized by a covariance ellipse in a sub-volume of 3 × 3 × 3 cubes. Mahalanobis distance was used to measure the distance of individual cube values to the origin of the ellipse and to further form local structure ‘S’ maps. The structural difference maps (ΔS) and mean difference maps (Δμ) were calculated by subtracting pre-therapy maps from maps at mid- and post-therapy. Corresponding maps based on CT images were also generated. Results: ΔS identified new areas of interest in the lung compared to conventional Δμ maps. ΔS for PET and CT gave a significantly elevated lung signal compared to a control group during and post-RT (p S between pre- and post-therapy for 18F-FDG-PET was the only parameter significantly associated with local lung dose (p = .04). Conclusions: The new method using local structures on 18F-FDG-PET provides a clearer uptake dose–response compared to conventional analysis and CT-based approaches and may be valuable in future studies addressing lung toxicity

Capital Social y gestión de demandas ciudadanas en el Municipio San Francisco. Estado Zulia

El presente artículo tiene como propósito el análisis de los elementos del capital social que se encuentran presentes en la gestión de demandas ciudadanas de las asociaciones de vecinos a la Alcaldía del Municipio San Francisco del Estado Zulia.Alos fines, se concretó un estudio de campo, descriptivo-analítico. El referente empírico fueron 20 Asociaciones de vecinos distribuidas en las parroquias que lo conforman. El instrumento utilizado consistió en un cuestionario tipo estándar; se hace énfasis en la observación directa o participante, las entrevistas abiertas, y el análisis de documentos proporcionados por los informantes clave. Los hallazgos dan cuenta de: a) El Capital Social de las asociaciones de vecinos del municipio, se distingue por ser medianamente positivo, pero enfrenta serias amenazas. b) La confianza y los valores éticos, se encuentran orientados hacia la baja y atentan contra la acción social y gestión de demandas de las asociaciones de vecinos; c) la participación como dimensión del capital social es restringida, limitada solo al voto; por lo que deslegitima la acción del gobierno local. Todo lo anterior refleja desconfianza hacia este tipo de organizaciones. e) Se percibe un espacio muy limitado para la construcción de ciudadanía y la generación de mecanismos de empoderamiento ciudadano, f) Se registra una inconsistencia entre el discurso, la acción y los resultados de la gestión gubernamental. Se concluye que estos rasgos se constituyen en una barrera para la legitimidad y gobernabilidad del gobierno local en cuestión