Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1619-7089
    Keywords: Positron emission tomography ; Fluorine-18 fluorophenylalanine ; Cerebral gliomas ; Large neutral amino acid transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To elucidate the mechanism of large neutral amino acid (LNAA) transport in cerebral gliomas and to evaluate the clinical usefulness of positron emission tomography (PET) with fluorine-18 fluorophenylalanine (18F-Phe), we examined 18 patients with cerebral glioma using dynamic PET and18F-Phe. By employing two-compartment model analysis, the influx rateK 1, the efflux ratek 2 and the distribution volume (V d) of18F-Phe were estimated in tumour tissue and contralateral normal grey matter.18F-Phe showed increased accumulation in tumour tissue regardless of the grade of malignancy in all patients. The rate of uptake of18F-Phe in high-grade glioma was significantly higher than in low-grade glioma (P 〈0.05). However, it was difficult to evaluate the tumour grade only from the18F-Phe accumulation in individual cases. Values ofK 1 andV d were significantly increased in the tumour tissue. TheK 1 value of the tumour tissue tended to decrease with increasing LNAA concentration in plasma. Therefore, influx of18F-Phe into tumour tissue is mainly related to the carrier-mediated active transport. It is concluded that PET with18F-Phe is of clinical value for tumour detection rather than assessment of tumour malignancy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-7373
    Keywords: subependymoma ; positron emission tomography ; 18F-fluorodeoxyglucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report the evaluation of a subependymoma of the septum pellucidum by positron emission tomography (PET) with analysis of 18F-fluorodeoxyglucose (FDG)kinetics. The tumor showed exceedingly low rates of glucose metabolism (rCMRG1) and kinetic constants (K1, K2, and K3). This hypometabolism indicates low cellular density and slow growth.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-7373
    Keywords: malignant glioma ; recombinant human tumor necrosis factor-α ; positron emission tomography ; hemocirculation ; glucose metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral hemocirculation and glucose metabolism in a malignant astrocytoma were repeatedly quantified before and after intracarotid injection of recombinant human tumor necrosis factor-α (rH-TNF) using positron emission tomography (PET). The patient received an intracarotid injection of a 3 × 104 U/m2 dose of rH-TNF three times over a two week period. PET was performed prior to and 24 hr after the first injection, and two weeks after the third injection. Prior to the first rH-TNF treatment, two lesions demonstrating high perfusion and hypermetabolism of glucose were noted in the right frontal and temporal regions. The frontal hypermetabolic lesion showed decreases in hemocirculation and metabolism 24 hr after the first injection and then increases beyond the pre-treatment level two weeks after the third treatment, whereas the temporal lesion remained unchanged during the follow-up period. No appreciable changes were noted in the adjacent cortex where rH-TNF was perfused, with the exception of a transient decrease in regional blood volume. Magnetic resonance images of the tumor showed no changes as a result of treatment with intracarotid rH-TNF. Intracarotid rH-TNF preferentially affects tumor tissue as opposed to normal cortex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-7373
    Keywords: positron emission tomography (PET) ; glioma ; glucose metabolism ; hemocirculation ; radiation therapy ; chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hemocirculatory and metabolic changes in tumor regions and the remote brain structure were analyzed using oxygen-15 and fluorine-18 positron emission tomography (PET) in eight patients with gliomas after radiation and chemotherapy of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and N-(2-tetrahydrofuryl)-5-fluorouracil (FT 207). In the tumor regions after the radiochemotherapy, regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV) varied widely and there was a tendency for oxygen consumption (rCMRO2) to fall. The change in glucose consumption (rCMRGI) was especially noteworthy with regard to clinical correlations. Six patients with decreased rCMRGI values had 16010 to 29010 regressions in tumor size measured by X-ray computerized tomography (CT), and showed some period of clinical relief. In contrast, one patient with an increased rCMRGI value had some progression of tumor growth, and there were no clinical amelioration. The hemocirculation and metabolism of the contralateral gray matter seem to fluctuate by various factors as intracranial pressure and the effectiveness of the therapy. In gliomas therapy, tumor rCMRGI values can be a good indicator of therapeutic effectiveness.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-7373
    Keywords: 18F-fluorodeoxyglucose ; kinetic analysis ; oligodendroglioma ; positron emission tomography ; tumor recurrence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To accurately characterize the pathophysiology and proliferating activity of oligodendrogliomas, we studied cerebral blood flow and metabolism using positron emission tomography (PET) in five patients with this tumor. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction fraction (rOEF), and cerebral metabolic rates of oxygen (rCMRO2) and of glucose (rCMRGl) were quantitatively measured in tumor lesions and the contralateral gray matter. rCMRGl was analyzed based on both kinetic and autoradiographic methods. Tumor rCBF and rCBV were lower than in the contralateral gray matter in all preoperatively examined patients. Oxygen metabolism, determined by rCMRO2 and rOEF, was consistently reduced in the tumor (rCMRO2, P〈0.05 vs. gray matter, determined by the Student's t-test). Tumor rCMRGl was significantly lower than the gray matter rCMRGl in both kinetic (P〈0.01) and autoradiographic (P〈0.05) analyses. Kinetic tumor rCMRGl varied between 1.22 and 4.13 mg/100 ml/min, but was lower than the gray matter value in all patients. Autoradiographic tumor rCMRGl, which ranged from 1.02 to 5.79 mg/100 ml/min, was also reduced in all tumors but one; the remaining tumor, which had a relatively high value of autoradiographic rCMRGl (comparable to gray matter rCMRGl), infiltrated the contralateral hemisphere through the corpus callosum, and was characterized by high cellular density. In one patient who suffered from tumor recurrence 8 years and 10 months after initial treatment, phosphorylation constant (K3) and kinetic rCMRGl of the recurring tumor were higher than those of the original tumor. No other tumors have regrown or recurred during the postoperative follow-up periods, which ranged from 22 to 130 months (median=101 months). Circulation and metabolism measured by PET provide in vivo biological characteristics, including proliferating activity, in oligodendrogliomas.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...