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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty-five patients with mass lesions involving the musculoskeletal system were studied with positron emission tomography (PET) in order to determine if a relationship exists between histologic grade and tumor uptake of [fluorine-18]2-deoxy-2-fluoro-D-glucose (FDG). There were 6 benign lesions and 19 malignant lesions of various grades. A high correlation (Rho = 0.83) was found between the normalized uptake of tracer and the NCl grade. The high-grade malignancies had significantly greater (p = 0.0091) uptake of FDG than the combination of benign lesions and low-grade malignancies. All lesions with a normalized uptake value of 1.6 or greater were high-grade, while all lesions less than 1.6 represented either benign tumors or low grade malignancies. This strong relationship between FDG uptake and grade among neoplasms from a wide variety of cell types within a single organ system suggests that the technique may be useful in predicting grade even when the cell type is unknown.
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PMID:Noninvasive grading of musculoskeletal tumors using PET. 186 70

The metabolic response of the RIF-1 tumor to 5-fluorouracil (a single dose of 260 mg 5FU/kg, ip) was monitored in 10 mice using 19F and 31P MR spectroscopy. 19F MRS revealed a continuous drop in tumor 5FU level and an increase in the fluoronucleotide (Fnuc) signal to a plateau value of 50% of the initial 5FU level, during the first 2 h after chemotherapy. Although the 31P MR spectra of the tumors showed no significant initial changes, the total level of MR visible tumor phosphate decreased and tumor pH increased during the subsequent days. The changes in phosphate metabolism and tumor pH did not correlate with the detected fluorine levels or tumor response. However, the pretreatment Pi level, the plateau Fnuc level, and the 5FU induced decrease in tumor volume showed significant correlation. This indicates that both 19F and 31P MR spectroscopy have potential for predicting response to 5FU chemotherapy.
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PMID:Multinuclear MR investigation of the metabolic response of the murine RIF-1 tumor to 5-fluorouracil chemotherapy. 190 37

The metabolism of 5-fluorouracil (5FU) in tumors and livers of RIF-1 tumor-bearing C3H mice given i.p. injections of 5FU was serially monitored by 19F magnetic resonance spectroscopy. The levels of 5FU and fluoronucleotide detected in the tumors after a dose of 130 mg/kg (n = 13) were less than one-third of those after 260-mg/kg 5FU (n = 14). During the days after these doses, tumor size decreased by 24 +/- 3 and 52 +/- 6 SEM%, respectively. A second 130-mg/kg dose, given at day 7 after the first 130-mg/kg dose, resulted in still lower tumor fluorine levels and little change in tumor size. There was a significant correlation between the magnetic resonance spectroscopy-detected fluoronucleotide levels and the shrinkage of tumors after the 260-mg/kg dose (r = 0.44; P = 0.024). In mouse liver, the degradation of 5FU to alpha-fluoro-beta-ureidoprobionic acid and alpha-fluoro-beta-alanine after the 260-mg dose (n = 13) was slower than after a dose of 130 mg/kg (n = 14). For the respective doses, the half-life of 5FU was 59 +/- 7 versus 28 +/- 2 SEM min (P less than 0.0001). There was a negative correlation between the levels of 5FU catabolite (alpha-fluoro-beta-ureidoprobionic acid and alpha-fluoro-beta-alanine) in liver and fluoronucleotide in tumor (r = -0.80; P = 0.0020), which indicates that the degradation in liver and the activation of 5FU in tumor are competing processes.
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PMID:19F magnetic resonance spectroscopy studies of the metabolism of 5-fluorouracil in murine RIF-1 tumors and liver. 199 77

The potential of the fluorine-18 labeled progestin 21-[18F]fluoro- 16 alpha-ethyl-19-norpregn-4-ene-3,20-dione [( 18F]FENP) as an imaging agent for the in vivo assessment of progestin receptor (PR) positive neoplasms with positron emission tomography has been investigated. Tissue distribution studies in immature estrogen primed female rats revealed high uptake of radioactivity, expressed as the differential absorption ratio, by uterine tissue. After simultaneous administration with unlabeled FENP, a significant decrease (83%) in uterine uptake was observed 60 min after injection. Uterine uptake was highly selective. The ratio of uptake of radioactivity by uterine tissue to that by blood was 39 at 180 min. In mice bearing transplanted Grunder strain mammary carcinomas tissue, distribution studies demonstrated a selective uptake of [18F]FENP by PR positive tumors. Pretreatment with unlabeled FENP caused a significant decrease (66%) in tumor uptake. Uptake by other tissues was not affected by the presence of unlabeled progestin. The ratio of uptake of radioactivity by tumor tissue to that by blood was 4.7 at 180 min. For FENP pretreated mice and mice bearing PR negative tumors, this ratio was 1.7 and 1.1, respectively. It is concluded that the uptake of [18F]FENP by uterine and by PR positive mammary tumor tissue in vivo is primarily receptor related, presumably to the PR. Furthermore, [18F]FENP appears to be suitable for imaging of PR positive human neoplasms with positron emission tomography.
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PMID:A fluorine-18 labeled progestin as an imaging agent for progestin receptor positive tumors with positron emission tomography. 200 78

With the advent of a new generation of PET scanners that have introduced whole-body PET to the clinical setting, there is now more interest in developing protocols for the evaluation of both intracranial and somatic cancers. The value of PET in clinical oncology has been demonstrated with studies in a variety of cancers including colorectal carcinomas, lung tumors, head and neck tumors, primary and metastatic brain tumors, breast carcinoma, lymphoma, melanoma, bone cancers, and other soft-tissue cancers. A summary of current clinical applications of PET in oncology is presented with special attention to colorectal, lung, and intracranial neoplasms since the majority of clinical trials have focused on these cancers. A variety of radiopharmaceuticals are described that are currently included in clinical tumor-imaging protocols, including metabolic substrates such as fluorine-18-fluorodeoxyglucose and carbon-11-methionine, and analogs of chemotherapeutic agents such as fluorine-18-fluorouracil and fluoroestradiol. An attempt is also made to include examples of clinical trials that demonstrate response to therapeutic intervention. The increasing number of oncologic PET studies reflects the growing interest in functional imaging in oncology.
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PMID:The applications of PET in clinical oncology. 201 3

Twenty-one patients with untreated malignant lymphoma in the head and neck region were evaluated with positron emission tomography (PET) using fluorine-18-fluorodeoxyglucose (FDG) and gallium-67 SPECT imaging. Tumor-to-normal soft-tissue contrast ratios (TCRs) obtained 60 min after injection of FDG were higher than 2.6, and all malignant lymphomas were clearly visualized. In patients with poor prognosis, higher TCRs and glucose utilization rates (GURs) were observed, whereas low TCR and GUR were shown in a patient with low-grade malignancy. In comparison with 67Ga scintigraphy, patients with high TCRs and GURs were likely to show increased accumulation of gallium-67, but accumulation of gallium-67 was not increased as much as FDG in poor prognostic patients. FDG-PET may be useful in the detection and management of malignant lymphoma.
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PMID:The use of FDG-PET in the detection and management of malignant lymphoma: correlation of uptake with prognosis. 201 8

Positron emission tomography (PET) using fluorine-18 (18F)-fluorodeoxyglucose (FDG) has been reported to be a powerful diagnostic and prognostic tool in patients with primary brain tumors. This study was undertaken to compare the prognostic value of: (1) visual grading of [18]FDG uptake in the tumor, (2) the absolute glucose metabolic rate of the tumor (TMRglc), (3) the ratio of glucose metabolism between the tumor and whole brain (T/WB) and (4) between the tumor and contralateral cerebellum (T/CBL). Each of these four parameters was correlated with the survival time in 20 patients with malignant cerebral gliomas. Excellent correlation was obtained with visual grading and reasonably good correlation was obtained with T/WB or T/CBL, but TMRglc alone was only a fair prognostic indicator. Thus, visual grading provides a qualitative analysis and T/WB provides a semi-quantitative analysis neither of which requires arterial blood sampling for quantification of absolute metabolic rates for glucose.
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PMID:New grading system of cerebral gliomas using positron emission tomography with F-18 fluorodeoxyglucose. 202 75

The authors assessed whether breast cancers can be detected by means of positron emission tomography (PET) with the positron-emitter-labeled glucose analogue 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG). In 12 patients with primary and/or metastatic breast cancer, PET images of F-18 distribution in vivo were obtained approximately 1 hour after intravenous injection of 10 mCi of FDG. Scan findings were correlated with other imaging data and physical examination and biopsy results. Ten of 10 primary breast cancers were imaged by means of FDG PET with a tumor:background FDG uptake ratio of 8.1 (median). Ten of 10 bone metastases were imaged with a tumor:normal bone uptake ratio of 6.05 (median). Five of five known soft-tissue metastases and four previously unsuspected nodal lesions were found with PET. No false-positive foci of FDG uptake were demonstrated. In two cases with negative mammograms due to dense breast parenchyma, FDG PET clearly delineated the primary tumors. These preliminary data demonstrate the feasibility and substantial potential of PET scanning with FDG to detect and localize both primary and metastatic breast cancers.
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PMID:Primary and metastatic breast carcinoma: initial clinical evaluation with PET with the radiolabeled glucose analogue 2-[F-18]-fluoro-2-deoxy-D-glucose. 202 89

Intraarterial 5-fluorouracil (5-FU) chemotherapy in eight patients, one with primary and seven with secondary liver tumors, was monitored by means of in vivo fluorine-19 magnetic resonance (MR) spectroscopy. F-19 MR spectra were obtained with surface coils and included signal contributions from both liver and tumor tissue. The time course of the relative concentrations of 5-FU and its major catabolite, alpha-fluoro-beta-alanine (FBAL), was followed for up to 100 minutes after the start of drug administration. The time constants for the kinetics of 5-FU ranged from 8 to 75 minutes, whereas the time constants for FBAL were either approximately 15 or 50 minutes. A broad peak comprising nucleoside and nucleotide anabolites of 5-FU was detected in one patient. These investigations demonstrate the feasibility of short-term therapy monitoring with F-19 MR spectroscopy and that catabolites and anabolites of 5-FU can be observed separately. However, since no F-19 MR spectroscopy localization sequence is available at present, the contributions to the total MR signal from normal liver and tumor tissue cannot be discriminated.
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PMID:Real-time follow-up of 5-fluorouracil metabolism in the liver of tumor patients by means of F-19 MR spectroscopy. 210 75

Indeno[1,2,3-cd]pyrene (IP) is a non-alternant polycyclic aromatic hydrocarbon that has tumor-initiating activity on mouse skin and is carcinogenic in newborn mice and in rat lungs. Previous studies have shown that 8- and 9-hydroxyIP and IP-1,2-diol are major metabolites formed in vivo in mouse skin. 8-HydroxyIP-1,2-diol and 9-hydroxyIP-1,2-diol are also observed as in vivo metabolites of IP. Although 8-hydroxyIP had marginal tumor-initiating activity on mouse skin, IP-1,2-diol and its epoxide precursor, IP-1,2-oxide, had similar tumorigenic activity as IP. In the present study fluorine probes have been employed to investigate the contribution of metabolic activation at the 1,2 and 7-10 positions of IP. At a total initiating dose of 4.0 mumol, 2-fluoroIP induced skin tumors in 76% of the treated animals with an average of 3.9 tumors/mouse. At the same dose, IP induced a 72% incidence of tumor-bearing mice with 2.1 tumors/mouse. In contrast, 8,9-difluoroIP elicited a tumorigenic response in 40% of the treated animals with 0.6 tumors/animal. Five mice from each experimental group were killed at the conclusion of the initiation phase of the bioassay and DNA was isolated from the treated areas of skin. 32P-Postlabeling analysis of the hydrolyzed DNA indicated that IP forms one major detectable DNA adduct that migrates close to the origin. This adduct is absent in mice treated with 8,9-difluoroIP. In contrast, 2-fluoroIP forms one major adduct spot with different retention behavior as compared with the adduct formed from IP. DNA from mice treated topically with IP-1,2-diol and IP-1,2-oxide was subjected to 32P-postlabeling analysis. IP-1,2-diol forms one major DNA adduct spot with mobility similar to that observed for the IP-DNA adduct. IP-1,2-oxide displayed an intense pattern of DNA adducts centered around the location of the IP-DNA adduct. No adducts were detected which had mobility similar to that formed from 2-fluoroIP. These results are consistent with IP undergoing metabolic activation at positions 7-10 either alone or in conjunction with dihydrodiol formation at the 1,2 position.
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PMID:Fluorine probes for investigating the mechanism of activation of indeno[1,2,3-cd]pyrene to a tumorigenic agent. 222 28


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