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Biomedical subjects

F Fazio

Publications and source records attributed to F Fazio.

At least 19 recordsLinked to original sources
PubMed2006

Integrated PET/CT as a first-line re-staging modality in patients with suspected recurrence of ovarian cancer.

PURPOSE: The aims of this study were to compare CT with PET/CT results in patients with suspected ovarian cancer recurrence and to assess the impact of the PET/CT findings on their clinical management. METHODS: Thirty-two consecutive patients with suspected ovarian cancer recurrence were retrospectively included in the study. Abdominal contrast-enhanced CT and PET/CT with [(18)F]FDG, in addition to conventional follow-up, were performed in all 32 patients. After the comparison between CT and PET/CT results, based on clinical reports, changes in the clinical management of patients (intermodality changes) due to PET/CT information were analysed. RESULTS: Twenty of the 32 patients were positive at CT (62.5%) versus 29 (90.6%) at PET/CT. Intermodality changes in management, i.e. use of a different treatment modality, after PET/CT examination were indicated in 14/32 (44%) patients. In particular, before PET/CT study, the planned management was as follows: wait-and-see in 7/32 (22%), further instrumental examinations in 4/32 (12%), chemotherapy in 10/32 (31%), diagnostic surgical treatment in 6/32 (19%) and surgical treatment in the remaining 5/32 (16%). After PET/CT study, wait-and-see was indicated in 1/32 (3%), further instrumental examinations in 7/32 (22%), chemotherapy in 16/32 (50%), diagnostic surgical treatment in 2/32 (6%) and surgical treatment in the remaining 6/32 (19%). CONCLUSION: Integrated PET/CT could detect tumour relapse in a higher percentage of patients than could CT. A change in the clinical management was observed in 44% of cases when PET/CT information was added to conventional follow-up findings.

Adult↗
PubMed2006

The influence of exercise on the daily rhythm of serum homocysteine in horses.

The aim of this study was to determine the daily rhythms in the blood serum of homocysteine in horses. Ten thoroughbred horses, five athletic (trained for 1 h, 6 days a week) and five sedentary, were used. Blood samples were collected on each subject every 4 h for two days by means of the jugular vein. On each individual sample, the serum concentration of homocysteine was assessed. The results obtained during the experimental period indicated the existence of a daily rhythm of serum homocysteine in sedentary and athletic horses. They also demonstrated that in horses, physical exercise influences the daily rhythm of serum homocysteine.

Animals↗
PubMed2006

Decommissioning procedures for an 11 MeV self-shielded medical cyclotron after 16 years of working time.

The present article describes the decommissioning of a compact, self-shielded, 11 MeV medical cyclotron. A Monte Carlo simulation of the possible nuclear reactions was performed in order to plan the decommissioning activities. In the course of the cyclotron dismantling, cyclotron components, shields, and floor concrete samples were measured. Residual activities were analyzed with a Ge(Li) detector and compared with simulation data. Doses to staff involved in the decommissioning procedure were monitored by individual TL dosimeters. The simulations identified five radioactive nuclides in shields and floor concrete: 55Fe and 45Ca (beta emitters, total specific activity: 2.29 x 10(4) Bq kg) and 152Eu, 154Eu, 60Co (gamma emitters, total specific activity: 1.62 x 10(3) Bq kg-1). Gamma-ray spectrometry confirmed the presence of gamma emitters, corresponding to a total specific activity of 3.40 x 10(2) Bq kg-1. The presence of the radioisotope 124Sb in the lead contained in the shield structure, corresponding to a simulated specific activity of 9.38 x 10(3) Bq kg-1, was experimentally confirmed. The measured dose from external exposure of the involved staff was <20 muSv, in accordance with the expected range of values between 10 and 20 muSv. The measured dose from intake was negligible. Finally, the decommissioning of the 11 MeV cyclotron does not represent a risk for the involved staff, but due to the presence of long-lived radioisotopes, the cyclotron components are to be treated as low level radioactive waste and stored in an authorized storage area.

Computer Simulation↗
PubMed2006

PET/CT and radiotherapy.

This article reviews the state of the art of PET/CT applications in radiotherapy, specifically its use in disease staging, patient selection, treatment planning and treatment evaluation. Diseases for which radiotherapy with radical intent is indicated will be considered, as well as those in which PET/CT may actually change the course of disease. The methodological and technological aspects of PET/CT in radiotherapy are discussed, focusing on the problem of target volume definition with CT and PET functional imaging and the problem of tumor motion with respect to imaging and dose delivery.

Humans↗
PubMed2005

Left caloric vestibular stimulation ameliorates right hemianesthesia.

BACKGROUND: Left caloric vestibular stimulation (CVS) transiently reduces impairments of right-brain-damaged patients with left unilateral neglect, including left hemianesthesia, contralateral to the side of the lesion (contralesional). Conversely, no effect on right contralesional hemianesthesia in left-brain-damaged patients is seen with right CVS. This discrepancy is unexplained. METHODS: The authors explored the effect of CVS on right- and left-brain-damaged patients with hemianesthesia. One left-brain-damaged patient had an fMRI study during tactile stimulation before and after left CVS. The same fMRI touch study, without CVS, was performed in neurologically unimpaired subjects. RESULTS: A transient remission of right hemianesthesia associated with left brain damage was observed, provided that cold CVS was administered to the left ear. In the left-brain-damaged patient studied with fMRI, left CVS modulated the neural response to right hand tactile stimuli of a portion of the secondary somatosensory area (SII) of the right hemisphere. In neurologically unimpaired subjects, fMRI scans showed that the same part of area SII in the right hemisphere was activated by ipsilateral right-sided touches and to a larger extent than area SII in the left hemisphere by left-sided touches. CONCLUSIONS: Left caloric vestibular stimulation is effective on both left and right hemianesthesia because it modulates the hemisphere that has a more complete representation of, or is capable to attend to, the whole somatosensory surface of the body. These results suggest a hardwired hemispheric asymmetry in hand representation, starting from a somatotopically organized brain region such as area SII.

Adult↗
PubMed2005

Improved synthesis and radiolabeling of [11C]MP4A, a suitable ligand for the investigation of the cholinergic system using PET.

An improved synthesis of the precursor acetic acid-piperidine-4-yl ester by acetylation of 4-hydroxypiperidine hydrochloride in anhydrous chloroform was developed. A procedure for fast evaluation and characterization of products originated by acetylation of the 4-piperidinol using LC-APCI/MS with an acetonitrile-water gradient method on a Merck Purosphere RP-18 column was also developed. The highly purified precursor allowed the production of [11C]MP4A for PET studies of acetylcholine neurotransmission system. The tracer was produced with >98% radiochemical purity, with yields ranging 20-60% (decay-corrected) from EOB.

Acetates↗
PubMed2005

A publicly accessible Monte Carlo database for validation purposes in emission tomography.

Monte Carlo (MC) methods provide ideal data sets to assess reconstruction and correction techniques in emission tomography (ET). Although several ET-dedicated MC codes are available, their use is hindered by the heavy computation burden required for high statistics simulations as well as by the need to adapt the code to the purpose of the individual user. In this work a publicly accessible database of MC-simulated ET data sets (the MC-ET database) was created and published on an Internet web site (http://www.ibfm.cnr.it/mcet/index.html), in order to provide MC-simulated data ready to be downloaded and used by researchers at different sites with similar evaluation purposes. At present, the MC-ET database provides direct access to MC-simulated raw data of unscattered, scattered and total events: (a) obtained by different MC codes, (b) relative to different radioactive sources, from simple geometrical phantoms to studies of normal and pathological subjects and (c) derived from different SPECT and PET scanners. The main features of the MC-ET data sets are: (a) validation by comparison with measured data, (b) classification according to pre-defined database characteristics, (c) common-use file format and (d) easy and free access and download.

Algorithms↗
PubMed2005

Brain abnormalities underlying altered activation in dyslexia: a voxel based morphometry study.

Voxel-based morphometry was used to assess the consistency among functional imaging and brain morphometry data in developmental dyslexia. Subjects, from three different cultural contexts (UK, France and Italy), were the same as those described in a previous PET activation paper, which revealed a common pattern of reduced activation during reading tasks in the left temporal and occipital lobes. We provide evidence that altered activation observed within the reading system is associated with altered density of grey and white matter of specific brain regions, such as the left middle and inferior temporal gyri and the left arcuate fasciculus. This supports the view that dyslexia is associated with both local grey matter dysfunction and with altered connectivity among phonological/reading areas. The differences were replicable across samples confirming that the neurological disorder underlying dyslexia is the same across the cultures investigated in the study.

Adult↗
PubMed2005

SPET in psychopharmacology.

Positron emission tomography (PET) and single photon emission tomography (SPET) permit the in vivo assessment of human biological processes with methods originally developed for preclinical studies. This opportunity is of primary interest in biological psychiatry and in psychoactive drugs development. Most of research efforts have focused on the use of PET field, and several biological finding on central nervous system (CNS) diseases have been published. Despite methodological limitations, the feasibility and usefulness of SPET for research, including full quantification, kinetic modeling and tracer validation, has been clearly demonstrated. The aim of this paper is to review advantages, limitations and results of SPET in psychopharmacology.

Animals↗
PubMed2005

Feasibility of [18F]FDG-PET and coregistered CT on clinical target volume definition of advanced non-small cell lung cancer.

AIM: To prospectively evaluate the impact of coregistered positron emission tomography (PET) and computed tomography (CT) in 3D conformal radiotherapy (3D-CRT) planning in patients with non-small lung cancer (NSCLC). METHODS: Twenty-one patients (median age: 57 years; range: 42-80 years) referred to 3D-CRT for NSCLC were recruited. Positron emission tomography with 18F-fluorodeoxyglucose ([18F]FDG-PET) and conventional CT images were coregistered (PET/CT images) using a commercial software package based on surface matching technique. Neoplastic areas were contoured on [18F]FDG-PET images with the aid of the correspondent CT image by a nuclear medicine physician. CT images and their relative PET contours were then transferred to treatment planning system. A radiation oncologist firstly contoured clinical target volumes (CTV) on CT scan alone (CTV-CT), and then on coregistered PET/CT images (CTV-PET/CT). CTV-CT and CTV-PET/CT were compared for each patient; a difference higher than 25% was considered of clinical relevance. RESULTS: Three patients were shifted to palliative radiotherapy for metastatic disease or very large tumor size, showed by [18F]FDG-PET. Of the remaining 18 patients a CTV change, after inclusion of PET/CT data, was observed in 10/18 cases (55%): larger in 7/18 (range 33-279%) and smaller in 3/18 patients (range 26-34%), mainly due to inclusion or exclusion of lymph-nodal disease and to better definition of tumor extent. CTV changes smaller than 25% occurred in the remaining 8/18 patients. CONCLUSIONS: [18F]FDG-PET and CT images co-registration in radiotherapy treatment planning led to a change in CTV definition in the majority of our patients, which may significantly modify management and radiation treatment modality in these patients.

Adult↗
PubMed2005

Automatic registration of PET and CT studies for clinical use in thoracic and abdominal conformal radiotherapy.

AIM: Implementation and validation of an automatic registration method based on mutual information (MI) for the integration of thoracic and abdominal positron emission tomography (PET)/computed tomography (CT) studies, with the purpose to facilitate in a clinical context the inclusion of PET metabolic information in conformal radiotherapy (RT). METHODS: Registration was obtained by modeling a rigid spatial transformation between CT and PET transmission studies. The registration method was based on Normalized Mutual Information (NMI), by iteratively transforming the PET volume, until its optimal alignment to the CT study is achieved, in correspondence of the maximum of NMI. To avoid entrapment in local maxima and to improve convergence speed we introduced a multiresolution scheme. Accuracy of the proposed approach was investigated in experimental data, relative to phantom and patient studies, acquired in conditions similar to clinical situations. RESULTS: In phantom studies the mean error in the 3D space is 3.6 mm (range 3-4 mm) in thoracic region and 3.2 mm (range 2.9-3.7 mm) in abdominal region, considerably less than PET spatial resolution. In patient studies the spatial mean error increases with respect to phantom studies (5.4 mm and 5.2 mm for thorax and abdomen, respectively) but remains comparable to the PET spatial resolution. The accuracy of spatial realignment was thus found adequate for the registration of PET/CT registration, if good patient repositioning was adopted. CONCLUSIONS: The proposed registration method, based on MI, was validated for the integration of PET/CT studies of patients candidate for thoracic and abdominal conformal RT. The method is automatic and provided with a user interface, thus suitable for clinical use.

Abdominal Neoplasms↗
PubMed2004

In vivo imaging of adenosine A2A receptors in rat and primate brain using [11C]SCH442416.

PURPOSE: The aim of this study was to evaluate the suitability of [11C]SCH442416 for the in vivo imaging of adenosine A2A receptors. METHODS: In rats and Macaca nemestrina, we evaluated the time course of the cerebral distribution of [11C]SCH442416. Furthermore, in rats we investigated the rate of metabolic degradation, the inhibitory effects of different drugs acting on adenosine or dopamine receptors and the modification induced by the intrastriatal administration of quinolinic acid (QA). RESULTS: The rate of metabolic degradation of [11C]SCH442416 in rats was slow; 60 min after tracer injection, more than 40% of total plasma activity was due to unmetabolised [11C]SCH442416. At the time of maximum uptake, radioactive metabolites represented only 6% of total extractable activity in the cerebellum and less than 1% in the striatum. In the striatum, the region with the highest expression of A2A receptors, the in vivo uptake of [11C]SCH442416 was significantly reduced only by drugs acting on A2A receptors or by QA, a neurotoxin that selectively reduces the number of intrastriatal GABAergic neurons. Position emission tomography (PET) studies in monkeys indicated that the tracer rapidly accumulates in brain, reaching maximum uptake between 5 and 10 min. Twenty minutes after the injection, radioactivity concentration in the striatum was two times that in the cerebellum. CONCLUSION: The specificity of binding, the rank order of regional distribution in the brain of rats and M. nemestrina, the good signal to noise ratios and the low amount of radioactive metabolites in brain and periphery indicate that [11C]SCH442416 is a promising tracer for the in vivo imaging of A2A adenosine receptors using PET.

Animals↗
PubMed2004

Regional reductions of gray matter volume in familial dyslexia.

An in vivo anatomic study of gray matter volume was performed in a group of familial dyslexic individuals, using an optimized method of voxel-based morphometry. Focal abnormalities in gray matter volume were observed bilaterally in the planum temporale, inferior temporal cortex, and cerebellar nuclei, suggesting that the underlying anatomic abnormalities may be responsible for defective written language acquisition in these subjects.

Adolescent↗
PubMed2004

Evaluation of three quinoline-carboxamide derivatives as potential radioligands for the in vivo pet imaging of neurodegeneration.

The peripheral-type benzodiazepine receptors (PBRs) are only minimally expressed in normal brain parenchyma, where they are primarily localized in glial cells. Their basal expression rises in different neurodegenerative disorders, due to the presence of infiltrating inflammatory cells and activated microglia. [11C]PK11195, a selective PBR antagonist, has been used for the in vivo PET monitoring of neurodegeneration in clinical observations. We recently developed and labeled with carbon-11 three new carboxamide derivatives: [11C]VC193M, [11C]VC195 and [11C]VC198M. Aim of this study was to evaluate these ligands for the in vivo measuring of PBRs expression in neurodegenerations and compare their kinetic behavior with that of the reference tracer [11C]PK11195. Radioligands were evaluated in a preclinical model of Huntington's disease consisting in the monolateral striatal injection of quinolinic acid (QA). Activated microglia and astrocytic gliosis was present only within the affected striatum. A concomitant increase in radioactivity accumulation was observed for all the tracers examined (P<0.01). Among the new compounds, [11C]VC195 showed higher levels of lesioned/unlesioned striatum ratios (3.28+/-0.44), in comparison with [11C]VC193M and [11C]VC198M (2.69+/-0.53 and 1.52+/-0.36, respectively), but slightly inferior to that observed for [11C]PK11195 (3.76+/-1.41).In conclusion, the results of the study indicate that [11C]VC195 is a promising candidate for in vivo PET monitoring of neurodegenerative processes but its in vivo behavior overlap that of [11C]PK11195.

Amides↗
PubMed2004

Brain activity during intra- and cross-modal priming: new empirical data and review of the literature.

A positron emission tomography (PET) study was conducted to investigate the neurofunctional correlate of auditory within-modality and auditory-to-visual cross-modality stem completion priming. Compared to the auditory-to-auditory priming condition, cross-modality priming was associated with a significantly larger regional cerebral blood flow (rCBF) decrease at the boundary between left inferior temporal and fusiform gyri, brain regions previously associated with modality independent lexical retrieval and reading. Instead, within-modality auditory priming was associated with a bilateral pattern of prefrontal rCBF increase. This was likely the expression of more efficient access to output lexical representations and involuntary retrieval of the recent episode during which the just generated word had been encountered.

Acoustic Stimulation↗
PubMed2004

Diagnosis of local recurrence after radical prostatectomy.

In the long-term there is biochemical evidence of recurrent prostate carcinoma in approximately 40% of patients after radical prostatectomy (RP). Detecting the site of recurrence (local vs distant) is critical for defining the optimum treatment. Pathological and clinical variables, e.g. Gleason score, involvement of seminal vesicles or lymph nodes, margin status at surgery, and especially the timing and pattern of prostate-specific antigen (PSA) recurrence, may help to predict the site of relapse. Transrectal ultrasonography (TRUS) of the prostatic fossa in association with TRUS-guided needle biopsy is considered more sensitive than a digital rectal examination for detecting local recurrence, especially if PSA levels are low. Although it cannot detect minimal tumour mass at very low PSA levels (< 1 ng/mL) TRUS biopsy is presently the most sensitive method for detecting local recurrence. Nevertheless, the conclusive role of biopsy of the vesico-urethral anastomosis remains unclear. However, 111In-capromab pendetide scintigraphy and [11C]-choline tomography (which are better than conventional imaging for detecting metastatic tumour), have low detection rates for local disease and are considered complementary to TRUS in this setting. Patients with a high PSA after RP may be managed with external beam salvage radiotherapy. An initial PSA of < 1 ng/mL, Gleason score < 8 and radiation dose of 66-70 Gy seem to be key factors in determining success. Although a positive TRUS anastomotic biopsy may predict a better outcome after radiation therapy, the need to take a biopsy in the event of PSA failure remains under investigation. The value of salvage radiation to the prostatic bed for PSA-only progression after RP remains in question.

Biopsy↗