174 research outputs found
Prognostic implications of Tc-99m sestamibi viability imaging and subsequent therapeutic strategy in patients with chronic coronary artery disease and left ventricular dysfunction.
AbstractOBJECTIVESThe aim of the study was to verify the prognostic implications of viability detection using baseline-nitrate sestamibi imaging in patients with left ventricular (LV) dysfunction due to chronic coronary artery disease (CAD) submitted to different therapeutic strategies.BACKGROUNDThe prognostic meaning of preserved viability in these patients is still debated. Sestamibi is increasingly used for myocardial perfusion scintigraphy and is being accepted also as viability tracer, but no data are available about the relationship between viability in sestamibi imaging, subsequent treatment, and patient’s outcome.METHODSFollow-up data were collected in 105 CAD patients with LV dysfunction who had undergone baseline-nitrate sestamibi perfusion imaging for viability assessment and had been later treated medically (group 1), or submitted to revascularization, which was either complete (group 2A) or incomplete (group 2B).RESULTSEighteen hard events (cardiac death or nonfatal myocardial infarction) were registered during the follow-up. A significantly worse event-free survival curve was observed in the patients of group 1 (p < 0.0002) and group 2B (p < 0.03) compared to those of group 2A. Using a Cox proportional hazard model, the most powerful prognostic predictors of events were the number of nonrevascularized asynergic segments with viability in sestamibi imaging (p < 0.003, risk ratio [RR] = 1.4), and the severity of CAD (p < 0.02, RR = 1.28).CONCLUSIONSViability detection in sestamibi imaging has important prognostic implications in CAD patients with LV dysfunction. Patients with preserved viability kept on medical therapy or submitted to incomplete revascularization represent high-risk groups
Multivariate analysis of brain metabolism reveals chemotherapy effects on prefrontal cerebellar system when related to dorsal attention network
BACKGROUND: Functional brain changes induced by chemotherapy are still not well characterized. We used a novel approach with a multivariate technique to analyze brain resting state [(18) F]FDG-PET in patients with lymphoma, to explore differences on cerebral metabolic glucose rate between chemotherapy-treated and non-treated patients. METHODS: PET/CT scan was performed on 28 patients, with 14 treated with systemic chemotherapy. We used a support vector machine (SVM) classification, extracting the mean metabolism from the metabolic patterns, or networks, that discriminate the two groups. We calculated the correct classifications of the two groups using the mean metabolic values extracted by the networks. RESULTS: The SVM classification analysis gave clear-cut patterns that discriminate the two groups. The first, hypometabolic network in chemotherapy patients, included mostly prefrontal cortex and cerebellar areas (central executive network, CEN, and salience network, SN); the second, which is equal between groups, included mostly parietal areas and the frontal eye field (dorsal attention network, DAN). The correct classification membership to chemotherapy or not chemotherapy-treated patients, using only one network, was of 50% to 68%; however, when all the networks were used together, it reached 80%. CONCLUSIONS: The evidenced networks were related to attention and executive functions, with CEN and SN more specialized in shifting, inhibition and monitoring, DAN in orienting attention. Only using DAN as a reference point, indicating the global frontal functioning before chemotherapy, we could better classify the subjects. The emerging concept consists in the importance of the investigation of brain intrinsic networks and their relations in chemotherapy cognitive induced changes
Post-ABVD/pre-radiotherapy 18F-FDG-PET provides additional prognostic information for early-stage Hodgkin lymphoma: A retrospective analysis on 165 patients
OBJECTIVE:
To evaluate the prognostic role of both interim fluorine-18 fludeoxyglucose positron emission tomography (i-(18)F-FDG-PET) and end-of-chemotherapy fluorine-18 fludeoxyglucose positron emission tomography (eoc-(18)F-FDG-PET) in patients with early-stage Hodgkin lymphoma (HL).
METHODS:
We screened 257 patients with early-stage HL treated with combined modality therapy between March 2003 and July 2011. All were staged using fluorine-18 fludeoxyglucose positron emission tomography ((18)F-FDG-PET) before chemotherapy and after two doxorubicin, bleomycin, vinblastine and dacarbazine cycles (i-(18)F-FDG-PET); 165 patients were also evaluated by (18)F-FDG-PET at the end of chemotherapy (eoc-(18)F-FDG-PET).
RESULTS:
After revision, 85% of patients were negative for i-(18)F-FDG-PET and 15% were positive. After eoc-(18)F-FDG-PET revision, 23 patients had a positive scan. The median follow-up was 56 months. The 5-year overall survival (OS) and progression-free survival (PFS) for the whole cohort were 97.5% and 95.6%, respectively. For i-(18)F-FDG-PET-negative and i-(18)F-FDG-PET-positive patients, the 5-year PFS rates were 98% and 84%, respectively; for eoc-(18)F-FDG-PET-negative and eoc-(18)F-FDG-PET-positive patients, the 5-year PFS rates were 97% and 78%, respectively. Combining the i-(18)F-FDG-PET and eoc-(18)F-FDG-PET results, the 5-year PFS were 97%, 100% and 82% in negative/negative, positive/negative and positive/positive groups, respectively. The 5-year OS rates were 98% and 83% in eoc-(18)F-FDG-PET-negative and eoc-(18)F-FDG-PET-positive patients, respectively; the 5-year OS was 98%, 100% and 83% in negative/negative, positive/negative and positive/positive groups, respectively.
CONCLUSION:
This study provides additional information on the prognostic role of i-(18)F-FDG-PET and eoc-(18)F-FDG-PET in early-stage HL. As data are accumulating and the clinical scenario is rapidly evolving, we might need to rethink the use of (18)F-FDG-PET as a prognostic marker for early-stage HL in the near future.
ADVANCES IN KNOWLEDGE:
This study provides additional information on the prognostic role of i-(18)F-FDG-PET and eoc-(18)F-FDG-PET in early-stage HL. On the basis of the present data, we may suggest to use eoc-(18)F-FDG-PET as a strong prognostic marker, especially for patients with i-(18)F-FDG-PET positivity
Chemotherapy effects on brain glucose metabolism at rest
Background: A growing number of studies reports that chemotherapy may impair brain functions inducing cognitive changes which can persist in a subset of cancer survivors.
Aims: To investigate the neural basis of the chemotherapy-induced neurobehavioral changes by means of metabolic imaging and voxel-based statistical parametric mapping analyses.
Methods: We studied the resting brain [18]FDG-PET/CT images of 43 adult cancer patients with solid (n=12, 28%) or hematologic malignancies (n=31, 72%); 12 patients were studied prior to chemotherapy (No chemotherapy) while treated patients were divided into two matched subgroups: Early High (6 chemotherapy cycles, n=10), and Late Low (>9 months after chemotherapy, <6 chemotherapy cycles, n=21).
Findings: Compared to No chemotherapy, the Early High subgroup showed a significant bilateral (p<0.05) lower regional cerebral metabolic rate of glucose metabolism in both the prefrontal cortices and white matter, cerebellum, posterior medial cortices and limbic regions. A similar pattern emerged in the Early High versus Low Late comparison, while no significant result was obtained in the Low Late versus No chemotherapy comparison. The number of cycles and the post-chemotherapy time were negatively and positively correlated, respectively, with a set of these same brain regions.
Interpretation: The present study shows that chemotherapy induces significant transient changes in the glucose metabolism of multiple cerebral cortical and white matter regions with a prevailing involvement of the prefrontal cortex. The severity of these changes are significantly related with the number of chemotherapy cycles and a subset of brain regions seems to present longer lasting, but more subtle, metabolic changes
Armida disvelata. L’immagine del velo nella "Gerusalemme liberata"
The essay takes into account the different occurrences of the term ‘veil’ in the Gerusalemme liberata. After an analysis of the metaphorical meanings of the term, the focus moves towards the veils that hide or embellish some of the female characters, in particular Sofronia, Erminia and Armida, bringing to light the different functions – even symbolic – that appear to be connected to this garment.The essay takes into account the different occurrences of the term ‘veil’ in the Gerusalemme liberata. After an analysis of the metaphorical meanings of the term, the focus moves towards the veils that hide or embellish some of the female characters, in particular Sofronia, Erminia and Armida, bringing to light the different functions – even symbolic – that appear to be connected to this garment
In vivo migration of labeled autologous natural killer cells to liver metastases in patients with colon carcinoma
BACKGROUND: Besides being the effectors of native anti-tumor cytotoxicity, NK cells participate in T-lymphocyte responses by promoting the maturation of dendritic cells (DC). Adherent NK (A-NK) cells constitute a subset of IL-2-stimulated NK cells which show increased expression of integrins and the ability to adhere to solid surface and to migrate, infiltrate, and destroy cancer. A critical issue in therapy of metastatic disease is the optimization of NK cell migration to tumor tissues and their persistence therein. This study compares localization to liver metastases of autologous A-NK cells administered via the systemic (intravenous, i.v.) versus locoregional (intraarterial, i.a.) routes. PATIENTS AND METHODS: A-NK cells expanded ex-vivo with IL-2 and labeled with (111)In-oxine were injected i.a. in the liver of three colon carcinoma patients. After 30 days, each patient had a new preparation of (111)In-A-NK cells injected i.v. Migration of these cells to various organs was evaluated by SPET and their differential localization to normal and neoplastic liver was demonstrated after i.v. injection of (99m)Tc-phytate. RESULTS: A-NK cells expressed a donor-dependent CD56(+)CD16(+)CD3(- )(NK) or CD56(+)CD16(+)CD3(+ )(NKT) phenotype. When injected i.v., these cells localized to the lung before being visible in the spleen and liver. By contrast, localization of i.a. injected A-NK cells was virtually confined to the spleen and liver. Binding of A-NK cells to liver neoplastic tissues was observed only after i.a. injections. CONCLUSION: This unique study design demonstrates that A-NK cells adoptively transferred to the liver via the intraarterial route have preferential access and substantial accumulation to the tumor site
The Murchison Widefield Array: The Square Kilometre Array Precursor at Low Radio Frequencies
The Murchison Widefield Array (MWA) is one of three Square Kilometre Array Precursor telescopes and is located at the Murchison Radio-astronomy Observatory in the Murchison Shire of the mid-west of Western Australia, a location chosen for its extremely low levels of radio frequency interference. The MWA operates at low radio frequencies, 80–300 MHz, with a processed bandwidth of 30.72 MHz for both linear polarisations, and consists of 128 aperture arrays (known as tiles) distributed over a ~3-km diameter area. Novel hybrid hardware/software correlation and a real-time imaging and calibration systems comprise the MWA signal processing backend. In this paper, the as-built MWA is described both at a system and sub-system level, the expected performance of the array is presented, and the science goals of the instrument are summarised
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