Search

20 februari 2022, Item does not contain fulltext, Individual informed consent is a central requirement for clinical research on human subjects, yet whether and how consent requirements should apply to health policy experiments (HPEs) remains unclear. HPEs test and evaluate public health policies prior to implementation. We interviewed 58 health experts in Tanzania, Bangladesh and Germany on informed consent requirements for HPEs. Health experts across all countries favored a strong evidence base, prior information to the affected populations, and individual consent for ‘risky’ HPEs. Differences pertained to individual risk perception, how and when consent by group representatives should be obtained and whether HPEs could be treated as health policies. The study adds to representative consent options for HPEs, yet shows that more research is needed in this field - particularly in the present Covid-19 pandemic which has highlighted the need for HPEs nationally and globally.

Depuis 2010, plus de cent pays ont demandé l’appui politique et le conseil technique de l’Organisation Mondiale de la Santé (OMS) sur la façon de réaliser une couverture sanitaire universelle (CSU). En réponse, l’OMS a constitué le Groupe Consultatif sur la Couverture Sanitaire Universelle et Equitable. Le rapport final du Groupe Consultatif traite des questions essentielles de justice et d’équité qui se posent lors du processus conduisant à la réalisation de la CSU en les clarifiant et en proposant des recommandations pratiques. Pour atteindre la CSU, les pays doivent faire des progrès dans au moins trois dimensions. Les pays doivent augmenter les services prioritaires, inclure plus de personnes, et réduire les paiements directs. Toutefois, dans chacune de ces dimensions, les pays sont confrontés à des choix difficiles: quels services étendre en premier, qui inclure en premier, et comment passer des paiements directs au prépaiement? Pour faire ces choix, les pays doivent d’être guidés par un engagement pour la justice - qui rejoint la préoccupation en matière d’équité - et l’engagement pour le respect des droits des personnes aux soins de santé. Une stratégie en trois volets peut guider les pays qui cherchent à réaliser la CSU de manière progressive et néanmoins équitable. Les pays peuvent : catégoriser les services en groupes prioritaires. Les critères pertinents pour cette catégorisation incluent le rapport coût-efficacité, la priorité aux plus démunis, et la protection contre le risque financier. étendre pour commencer la couverture des services de haute priorité à tous. Cela inclut l’élimination des paiements directs et le recours accru aux prépaiements obligatoires, progressifs et mettant en commun les fonds. ce faisant, veiller à ne pas laisser à la traine les groupes désavantagés. Il s’agira le plus souvent de groupes à revenus faibles et de populations rurales. Dans le cadre d’une stratégie plus globale, les pays doivent effectuer des choix minutieux au sei

Contains fulltext : 138134.pdf (publisher's version ) (Open Access), This Guidance for Priority Setting in Health Care (GPS-Health), initiated by the World Health Organization, offers a comprehensive map of equity criteria that are relevant to health care priority setting and should be considered in addition to cost-effectiveness analysis. The guidance, in the form of a checklist, is especially targeted at decision makers who set priorities at national and sub-national levels, and those who interpret findings from cost-effectiveness analysis. It is also targeted at researchers conducting cost-effectiveness analysis to improve reporting of their results in the light of these other criteria. THE GUIDANCE WAS DEVELOP THROUGH A SERIES OF EXPERT CONSULTATION MEETINGS AND INVOLVED THREE STEPS: i) methods and normative concepts were identified through a systematic review; ii) the review findings were critically assessed in the expert consultation meetings which resulted in a draft checklist of normative criteria; iii) the checklist was validated though an extensive hearing process with input from a range of relevant stakeholders. The GPS-Health incorporates criteria related to the disease an intervention targets (severity of disease, capacity to benefit, and past health loss); characteristics of social groups an intervention targets (socioeconomic status, area of living, gender; race, ethnicity, religion and sexual orientation); and non-health consequences of an intervention (financial protection, economic productivity, and care for others).

BACKGROUND AND PURPOSE: MR imaging-based apparent diffusion coefficient (ADC) and regional cerebral blood volume (rCBV) measurements have been related respectively to both cell and microvessel density in brain tumors. However, because of the high degree of heterogeneity in gliomas, a direct correlation between these MR imaging-based measurements and histopathologic features is required. The purpose of this study was to correlate regionally ADC and rCBV values with both cell and microvessel density in gliomas, by using coregistered MR imaging and stereotactic biopsies. MATERIALS AND METHODS: Eighteen patients (9 men, 9 women; age range, 19-78 years) with gliomas underwent diffusion-weighted and dynamic susceptibility contrast-enhanced MR imaging before biopsy. Eighty-one biopsy samples were obtained and categorized as peritumoral, infiltrated tissue, or bulk tumor, with quantification of cell and microvessel density. ADC and rCBV values were measured at biopsy sites and were normalized to contralateral white matter on corresponding maps coregistered with a 3D MR imaging dataset. ADC and rCBV ratios were compared with quantitative histologic features by using the Spearman correlation test. RESULTS: The highest correlations were found within bulk tumor samples between rCBV and cell density (r=0.57, P < .001) and rCBV and microvessel density (r=0.46, P < .01). An inverse correlation was found between ADC and microvessel density within bulk tumor (r=-0.36, P < .05), whereas no significant correlation was found between ADC and cell density. CONCLUSION: rCBV regionally correlates with both cell and microvessel density within gliomas, whereas no regional correlation was found between ADC and cell density., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

PURPOSE: The detection of recurrent pituitary adenoma by magnetic resonance imaging (MRI) is rendered uncertain by the tissue remodelling that follows surgery or radiotherapy. We aimed to evaluate the contribution of PET with 11C-methionine (MET-PET) in the detection and management of recurrent pituitary adenoma. METHODS: Thirty-three patients with pituitary adenoma were evaluated postoperatively by MET-PET, either because of biological evidence of active residual tumour or because of MRI demonstration of non-functional adenoma growth. We studied 24 secreting adenomas and nine non-functional adenomas. RESULTS: In 30 patients, MET-PET detected abnormally hypermetabolic tissue. In 14 out of these, MRI did not differentiate between residual tumour and scar formation. In nine of these 14 cases, major therapeutic decisions were undertaken (radiosurgery and surgery). In another group of 16 patients, both MET-PET and MRI detected abnormal tissue. In one case, neither MRI nor MET-PET detected adenomatous tissue. Finally, abnormal tissue was detected in two patients on MRI solely. In these two cases, failure of MET-PET to reveal the adenoma was attributable to concomitant inhibitory therapy. The sensitivity of MET-PET and MRI varied as a function of the tumour type: all non-functional adenomas were localised by both modalities, while MET-PET detected all adrenocorticotropic hormone-secreting adenomas whereas MRI depicted only one of these eight lesions. Fifteen out of 17 patients treated by radiosurgery showed clinical improvement after treatment. CONCLUSION: We suggest that MET-PET is a sensitive technique complementary to MRI for the detection of residual or recurrent pituitary adenomas. It should gain a place in the efficient management of these tumours., Journal Article, SCOPUS: ar.j, info:eu-repo/semantics/published

OBJECT: Positron emission tomography with L-[methyl-11C]methionine (MET-PET) provides information on the metabolism of gliomas. The aim of this study was to determine the predictive value of MET-PET in the treatment of patients with gliomas. METHODS: Since 1992, 85 patients with a World Health Organization (WHO) classification-verified glioma underwent PET studies in which MET was injected before (74 cases) or after treatment (11 cases). Analysis of PET data was conducted by the same investigator using two scales: a qualitative visual grading scale and a quantitative scale (ratio between tumor uptake and normal brain uptake, classified on a seven-level scale). Uptake of MET was present in 98% of gliomas. The investigator judged this uptake to be moderate to very high based on visual inspection (qualitative scale). For all grades of gliomas, a visual grade of 3 was statistically associated with a shorter patient survival period (p < 0.005). The tumor/normal brain uptake ratio was significantly influenced by the histological grade of the tumor. A statistically poor outcome was demonstrated when this ratio was higher than a threshold of 2.2 for a WHO Grade II tumor and 2.8 for WHO Grade III tumor. For Grade II and III tumors, oligodendrogliomas had a higher uptake of MET than astrocytomas. CONCLUSIONS: Uptake of MET was present in 98% of the gliomas studied. A high uptake is statistically associated with a poor survival time. The intensity of MET uptake represents a prognostic factor for WHO Grade II and III tumors considered separately., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

We investigated statistical parametric mapping (SPM) use for positron emission tomography (PET) with [(18)F]fluorodeoxyglucose (FDG) data analysis in mesial temporal lobe epilepsy. The study involved 14 patients with temporal lobe epilepsy ultimately treated by anterior temporal lobectomy. Surgical outcome in terms of seizure control was favorable in 12 patients. Two different SPM approaches were designed to analyze each FDG-PET scan: a direct comparison with a control group (n = 27) and a search for significant interhemispheric asymmetry considering the asymmetry existing in the control group. Statistical inference was performed, first, without correction for multiple comparisons (making the hypothesis of temporal hypometabolism) and, second, after correction for multiple comparisons. Search for temporal interhemispheric asymmetry under the hypothesis of temporal hypometabolism was the most reliable SPM approach: hypometabolism was identified on the side chosen for resection in most cases (sensitivity, 71%; specificity, 100%) and was predictive of favorable postsurgical outcome in 90% of the patients. There was no false-positive result within the control group using this approach. After correction for multiple comparisons, SPM also identified in some patients temporal hypermetabolic areas as well as extratemporal cortical and subcortical hypometabolic areas on the side of resection but also on the contralateral side. In a further step, SPM was used for a group analysis of patients with favorable outcome after reversing scans when needed to set an identical lateralization in all patients. This analysis identified multiple ipsilateral temporal and extratemporal hypometabolic regions; when temporal metabolic changes were specifically assessed, the contralateral mesiotemporal region was found hypermetabolic, possibly as a manifestation of compensatory mechanisms in the presence of a unilateral epileptogenic lesion., Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

OBJECT: In the management of brainstem lesions, the place of stereotactic biopsy sampling remains debatable. The authors compared the results of magnetic resonance (MR) imaging, positron emission tomography (PET) scanning, and histological studies obtained in 30 patients who underwent MR imaging- and PET-guided stereotactic biopsy procedures for a brainstem mass lesion. METHODS: Between July 1991 and December 1998, 30 patients harboring brainstem mass lesions underwent a stereotactic procedure in which combined MR imaging and PET scanning guidance were used. Positron emission tomography scanning was performed using [18F]fluorodeoxyglucose in 16 patients, methionine in two patients, and both tracers in 12 patients. Definite diagnosis was established on histological examination of the biopsy samples. Interpretation of MR imaging findings only or PET findings only was in agreement with the histological diagnosis in 63% and 73% of cases, respectively. Magnetic resonance imaging and PET findings were concordant in 19 of the 30 cases; in those cases, imaging data correlated with histological findings in 79%. Treatment based on information derived from MR imaging was concordant with therapy based on histological findings in only 17 patients (57%). Combining MR imaging and PET scanning data, the concordance between the neuroimaging-based treatment and treatments based on histological findings increased to 19 patients (63%). In seven patients who underwent biopsy procedures with one PET-defined and one MR imaging-defined trajectory, at histological examination the PET-guided samples were more representative of the tumor's nature and grade than the MR imaging-guided samples in four cases (57%). In 18 patients PET scanning was used to define a biopsy target and provided a diagnostic yield in 100% of the cases. CONCLUSIONS: Although the use of combined PET and MR imaging improves radiological interpretation of a mass lesion in the brainstem, it does not accurately replace histo, Comparative Study, Journal Article, info:eu-repo/semantics/published

Positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) studies of 42 subjects ages 6 to 38 years were analyzed using statistical parametric mapping to identify age-related changes in regional distribution of glucose metabolism adjusted for global activity. Whereas adults were normal volunteers, children had idiopathic epilepsy. We studied polynomial expansions of age to identify nonlinear effects and found that adjusted glucose metabolism varied very significantly in the thalamus and the anterior cingulate cortex and to a lesser degree in the basal ganglia, the mesencephalon, and the insular, posterior cingulate, frontal, and postcentral cortices. Regression plots slowed that the best fit was not linear: adjusted glucose metabolism increased mainly before the age of 25 years and then remained relatively stable. Effects persisted when anti-epileptic drug intake and sleep during the FDG uptake were considered as confounding covariates. To determine if the metabolic changes observed were not due to the epileptic condition of the children, PET data obtained in adults with temporal lobe epilepsy were compared with those in our group of normal adult subjects, resulting in the absence of mapping in the age-related regions. This study suggests that brain maturation from the age of 6 years gives rise to a relative increase of synaptic activities in the thalamus, possibly as a consequence of improved corticothalamic connections. Increased metabolic activity in the anterior cingulate cortex is probably related to these thalamic changes and suggests that the limbic system is involved in the processes of brain maturation., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

Gliomas are regionally heterogeneous tumors. The local relationship between histologic features and radiotracer uptake evaluated by PET should therefore influence analysis and interpretation of PET results on gliomas, This study explored this local relationship as a result of PET guidance of stereotactic biopsies. Methods: Local histology was confronted to the regional uptake of F-18-2-fluoro-2-deoxy-D-glucose (F-18-FDG) and C-11-methionine (C-11-MEF) in 14 patients with high-grade glioma diagnosed during a procedure of PET-guided stereotactic biopsies, We analyzed the uptake of both tracers in regions of interest centered on the stereotactic coordinates of 93 biopsy samples. Results: A semiquantitative analysis revealed a significant regional correlation between C-11-MET and F-18-FDG uptakes. Uptake of both tracers was significantly higher on the site of tumor samples showing anaplastic changes than in the rest of the tumor. Presence of necrosis in anaplastic areas of the tumor significantly reduced the uptake of C-11-MET, Conclusion: PET with C-11-MET and F-18-FDG may help to evaluate, in vivo, the metabolic heterogeneity of human gliomas, Anaplasia is a factor of increased uptake of both tracers, but microscopic necrosis in anaplastic areas influences their uptake differently, This finding probably relates to the differences in tracer uptake by non-neoplastic components of necrotic tumors. These results underline the complementary role oF F-18-FDG and C-11-MET for the study of brain tumors and favors their use for stereotactic PET guidance of diagnostic or therapeutic procedures.

OBJECTIVE: The natural history of the supratentorial low-grade glioma (LGG) of the adult is variable, and its malignant transformation is hardly predictable. Because positron emission tomography with [18F]fluoro-2-deoxy-D-glucose (FDG) has prognostic value in high-grade gliomas, this study was designed to search for a possible relationship between glucose metabolism and risk of malignant evolution in LGGs. METHODS: Positron emission tomography with FDG was performed in 28 patients with LGGs (22 at the time of diagnosis and 6 after the diagnosis). A metabolic grading system based on the visual inspection of the positron emission tomographic images was used. RESULTS: In 19 patients, no area of FDG uptake higher than in the white matter was detected (metabolic Grade 1). All of those patients were alive at the end of the follow-up period. Only one of the patients presented a histological modification 7 months after the diagnosis. Nine patients presented areas of increased FDG uptake (metabolic Grade 2 or 3). Those areas were found in the tumor area in eight patients and in an area of radionecrosis in one. Of the nine patients with FDG "hot spots," six died, two had recurrence but were alive at the end of the follow-up period, and the patient with radionecrosis had no signs of recurrence. CONCLUSIONS: The presence of areas of increased FDG uptake in a histologically proven LGG predicts, in most cases, a deleterious evolution. This metabolic feature, detectable with a noninvasive procedure, may provide a clue to cellular changes, announcing malignant transformation in a tumor that retains the histological features of an LGG. Protocols with aggressive therapeutic strategies in this situation should be considered for evaluation., Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published