Diazepam and Jacobson's progressive relaxation show similar attenuating short-term effects on stress-related brain glucose consumption.

A non-pharmacological method to reduce anxiety is "progressive relaxation" (PR). The aim of the method is to reduce mental stress and associated mental processes by means of progressive suppression of muscle tension. The study was addressed to evaluate changes in brain glucose metabolism induced by PR in patients under a stressing state generated by a diagnostic medical intervention. The effect of PR was compared to a dose of sublingual diazepam, with the prediction that both interventions would be associated with a reduction in brain metabolism. Eighty-four oncological patients were assessed with 18F-fluorodeoxyglucose-positron emission tomography. Maps of brain glucose distribution from 28 patients receiving PR were compared with maps from 28 patients receiving sublingual diazepam and with 28 patients with no treatment intervention. Compared to reference control subjects, the PR and diazepam groups showed a statistically significant, bilateral and generalized cortical hypometabolism. Regions showing the most prominent changes were the prefrontal cortex and anterior cingulate cortex. No significant differences were identified in the direct comparison between relaxation technique and sublingual diazepam. Our findings suggest that relaxation induced by a physical/psychological procedure can be as effective as a reference anxiolytic in reducing brain activity during a stressful state.

Pruebas de diagnóstico por la imagen: ¿generan ansiedad? / Diagnostic imaging studies: do they create anxiety?

El cáncer constituye uno de los principales problemas de salud en los países occidentales. En el año 2008 fue la primera causa de muerte en varones y la segunda en mujeres. En el contexto de pacientes con sospecha o diagnóstico de cáncer, la realización de pruebas diagnósticas desempeña un papel central de la actividad clínica y puede tener un elevado impacto psicológico. Objetivo. Evaluar el grado de ansiedad que presentan los pacientes oncológicos que se realizan un estudio PET-TAC en un Servicio de Medicina Nuclear, mediante el cuestionario State Trait Anxiety Inventory (STAI). Material y método. Doscientos pacientes que se realizaron un estudio PET-TAC en un Servicio de Medicina Nuclear realizaron el cuestionario STAI para valorar el grado de ansiedad que genera la realización de esta prueba. El STAI es un cuestionario validado desarrollado como herramienta de investigación de la ansiedad en adultos sanos. Resultados. De los 200 pacientes, dos tercios (n=135; 67%) presentaban ansiedad. De los 133 que realizaron el estudio por primera vez, el 70% (n=93) estaba ansioso. De los 67 que ya se habían realizado el estudio con anterioridad un 62,7% (n=42) estaba ansioso. Los pacientes que presentaron mayor ansiedad son los que se realizaron el estudio para estadificar inicialmente la enfermedad. Conclusión. La realización de un estudio PET-TAC como método de estadificación inicial y/o para valorar una recurrencia tumoral es un importante generador de ansiedad, de forma estadísticamente significativa. Existe un elevado impacto emocional y cognitivo asociado a la participación de pruebas de diagnóstico(AU)

Cancer is one of the main health problems in western countries. In 2008, it represented the first cause of death in men and the second one in women. When there is a diagnosis or suspicion of cancer, performing diagnostic imaging studies has an important role in the clinical activity and may have an elevated psychological impact. Objective. The purpose of this study was to evaluate the level of anxiety in oncology patients during the performance of a nuclear medicine study (PET-CT) in a Nuclear Medicine Service, by means of the State Trait Anxiety Inventory (STAI). Material and methods. A total of 200 cancer patients who underwent a PET-CT study in a Nuclear Medicine Service were administered the STAI to evaluate the level of anxiety generated during this test. The STAI is a validated questionnaire developed as a research tool on anxiety in healthy adults. Results. Of the 200 patients, two thirds (n=135) (67%) of the patients evaluated had anxiety. Of the 133, 93 (70%) of the patients who underwent PET-CT study for the first time were anxious whereas 42 (62.7%) of the patients who had undergone the study on previous occasions were anxious. Those patients with the greatest anxiety were those in whom the study was performed to initially stage the disease. Conclusion. Performing the PET-CT study as an initial staging method and/or to evaluate tumor recurrence is an important and statistically significant generator of anxiety. There is a high emotional and cognitive impact associated to the participation of the diagnostic tests(AU)

Comparison of positron emission tomography (PET) and computed tomography (CT) for better target volume definition in radiation therapy planning

BACKGROUND: In cancer patients, positron emission tomography/ computed tomography (PET/CT) fused images present less variability in target contouring, respect to use only CT images, respectively. However, the gold standard has not yet been clearly established between radiation oncologists with regard to PET images and the methodology of contouring targets with confidence using PET/CT fused images. The aim of this study was to determine whether integrated PET/CT fused images provide advantages in virtual simulation compared with morphological contouring only with CT. MATERIAL AND METHODS: Thirty cancer patients were evaluated in an adapted PET/CT hybrid in radiotherapy (RT) setup position, with 20 of them being suitable for RT: 17 were suitable for curative intent, which was the group of interest in this study. All image series were sent to the RT work station (WS) where CT and PET series were automatically fused by Digital Imaging and Communications in Medicine (DICOM) in each case. PET series were threshold and were subjected to source-to-background contrast algorithms to fi nally redefine the original tumour description. Three different radiotherapy plans (RTP) for each patient were compared after targets were contoured: [1] planning over metabolic (PET) contoured targets, [2] planning over only morphologic (CT) targets, and [3] planning over targets obtained for treatment based on fused PET/CT images. RESULTS: PET/CT findings altered initial-stage planning in four patients (23.5%) because they had been undergoing chemotherapy. Gross target volume (GTV) and planning target volume (PTV) based only on PET showed more homogeneity to obtain mean doses (p = 0.025) with respect to those based on PET/CT, respectively. However, no percentage differences were observed in median PTV doses between the planning methods, although there was higher variability in PET/CT planning. Morphological (CT) and PET/ CT target volumes were more voluminous than metabolic (PET) volumes. On the other hand, 20% of metabolic (PET) PTV were out of those defined by PET/CT. Thoracic RT plans based on PET preserved better bilateral lung [percentage volume of lung irradiated with a dose of 20 Gy (V20); significance, R(2) = 0.559, p = 0.006]. CONCLUSIONS: For our physicians, PET/CT fused images allowed better contouring of primary tumours in 40% of head and neck cancers and 34% of thoracic cancers. PET/CT provides useful information for virtual simulation therapy. Image treatment and planning in an RT workstation is mandatory (AU)

Differences in response to food stimuli in a rat model of obesity: in-vivo assessment of brain glucose metabolism.

OBJECTIVE: Food intake is regulated by factors that modulate caloric requirements as well as food's reinforcing properties. In this study, we measured brain glucose utilization to an olfactory stimulus (bacon scent), and we examined the role of food restriction and genetic predisposition to obesity on such brain metabolic activity. METHODS: Zucker obese (Ob) and lean (Le) rats were divided into four groups: (1) Ob ad-libitum fed, (2) Ob food restricted (70% of ad libitum), (3) Le ad-libitum fed and (4) Le food restricted. Rats were scanned using micro-positron emission tomography and 2-[(18)F]-fluoro-2-deoxy-D-glucose under two conditions: (1) baseline scan (no stimulation) and (2) challenge scan (food stimulation, FS). RESULTS: FS resulted in deactivation of the right and left hippocampus. Ob rats showed greater changes with FS than Le rats (deactivation of hippocampus and activation of the medial thalamus) and Ob but not Le animals deactivated the frontal cortex and activated the superior colliculus. Access to food resulted in an opposite pattern of metabolic changes to the food stimuli in olfactory nucleus (deactivated in unrestricted and activated in restricted) and in right insular/parietal cortex (activated in unrestricted and deactivated in restricted). In addition, restricted but not unrestricted animals activated the medial thalamus. CONCLUSIONS: The greater changes in the Ob rats suggest that leptin modulates the regional brain responses to a familiar food stimulus. Similarly, the differences in the pattern of responses with food restriction suggest that FS is influenced by access to food conditions. The main changes with FS occurred in the hippocampus, a region involved in memory, the insular cortex, a region involved with interoception (perception of internal sensations), the medial thalamus (region involved in alertness) and in regions involved with sensory perception (olfactory bulb, olfactory nucleus, occipital cortex, superior colliculus and parietal cortex), which corroborates their relevance in the perception of food.