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

In 27 examinations of 24 patients with differentiated thyroid carcinoma an alternating pattern of metastases with either 131I- or FDG-uptake was found. In the follow-up of these patients this flip-flop pattern was seen in 89% (17/19) of patients with metastases and uptake of 131I or FDG as described here as uptake types 1 and 2 (type 1: FDG-positive and 131I-negative; type 2: FDG-negative and 131I-positive). In 4 patients a mixed type was observed (uptake type 3), i.e. a combination of metastases with uptake types 1 and 2 in the same patient. Metastases of papillary or follicular thyroid carcinoma without uptake of iodine have all been found to be FDG-positive in patients with an increase of thyroglobulin and with negative diagnostic results from other imaging modalities, and were histologically confirmed by surgery. False-negative or false-positive cases were not observed in this study. The FDG uptake showed an inverse proportionality to iodine uptake and to tumor differentiation. Increased glucose metabolism is a sign of higher malignancy.
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PMID:[18FDG whole-body PET in differentiated thyroid carcinoma. Flipflop in uptake patterns of 18FDG and 131I]. 767 41

Indium-111 satumomab pendetide (In-111 OncoScint) planar and SPECT imaging and F-18 FDG positron emission tomography (PET) have been found individually to be helpful in the detection of recurrent colorectal and ovarian cancer, but have not been compared. Twelve patients who were examined for recurrent colorectal or ovarian carcinoma underwent both In-111 OncoScint imaging and F-18 FDG PET imaging. All had normal or equivocal results of CT or MR studies. Tumor detection abilities were similar in most cases. However, Oncoscint demonstrated an advantage in the detection of carcinomatosis. PET demonstrated an advantage in detecting focal tumor recurrence in one case and, not unexpectedly, in detecting liver metastases. All positive nuclear studies for tumor were found to be true-positives at pathology (7 patients), or by diagnostic new CT changes (1 patient). Finally, unreported, bone marrow, bowel, and colostomy sites appear to be normal sites of localization of F-18 FDG 1 hour after injection.
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PMID:Indium-111 OncoScint CR/OV and F-18 FDG in colorectal and ovarian carcinoma recurrences. Early observations. 775 Feb 17

Correct preoperative staging of malignant tumors is a prerequisite for an adequate therapy. This is not always possible with the imaging techniques available. Often, only an exploratory laparotomy can give the final diagnosis. Therefore, the search is on for a non-invasive technique for staging. Positron emission tomography (PET) is a new method in nuclear medicine; it is used for the diagnosis of primary tumors, for staging, and for follow-up after therapy. With PET, biochemical pathways and physiological functions are studied, in contrast to CT and MRI, with which anatomy and morphology are examined. In our department PET was used in 26 patients with invasive bladder cancer, in 11 patients with renal cell carcinoma and in 1 patient for follow-up after testicular cancer. The primary bladder tumor was found in 85% of cases; in 4 a non-organ-confined tumor was diagnosed preoperatively. Specificity in staging of lymph nodes was 86% (18/21); in 3 patients lymph nodes were false-positive on PET. However, in 5 patients all lymph node metastases were found by PET. Renal cell carcinoma were found in 8 out of 9 patients; in 2 patients with high-grade tumors an FDG-uptake defect was found. Lymph node staging was accurate in 9 patients without metastases and in 2 with metastases. One patient had a slightly enlarged retroperitoneal lymph node in the follow-up of a non-seminomatous germ cell tumor, which was positive on PET. Histology confirmed that it was the only positive lymph node within the whole specimen after retroperitoneal lymphadenectomy. PET gives new insights in uro-oncology by examination of the metabolism. Our initial results are promising and warrant further studies.
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PMID:[Positron emission tomography. Introduction of a new procedure in diagnosis of urologic tumors and initial clinical results]. 775 85

Two cases of postsurgical brain tumor evaluation in which MRI was inconclusive are discussed. Functional imaging techniques, such as FDG-PET and 201TI SPECT, were used in both cases for distinguishing radiation necrosis from tumor recurrence. These methods proved to be complimentary. For Patient 1, FDG-PET showed more limitations compared to 201TI SPECT. FDG-PET results on the other hand, were consistent with the final diagnosis and the SPECT image was false positive for tumor recurrence in Patient 2.
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PMID:PET versus SPECT in distinguishing radiation necrosis from tumor recurrence in the brain. 779 71

We reported a case in which 99mTc-PMT scintigraphy was useful in diagnosing orbital metastasis of HCC. The case involved a 70 y.o. male, who had undergone nine transcatheter arterial embolizations over two years because of HCC and who had a past history of gastric cancer. The patient had complained of headache and visual disturbance for two months. Cranial CT and MRI studies showed a large homogeneous mass with remarkable bone destruction in the right lateral orbital wall. Because AFP was elevated, orbital metastasis of HCC was suspected, and 99mTc-PMT scanning was performed. On the planar and SPECT images, very high uptake was found in the right orbital tumor. The FDG-PET study showed remarkable hypermetabolism in the medial portion of tumor and follow-up MRI revealed that the tumor had expanded and invaded to the medial side of the orbit. 99mTc-PMT scanning was critical in diagnosing this case of orbital metastasis, and FDG-PET imaging was useful in determining the most active portion of the tumor.
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PMID:[Usefulness of 99mTc-PMT SPECT and 18F-FDG PET in diagnosing orbital metastasis of hepatocellular carcinoma]. 780 27

To evaluate the usefulness of FDG-PET as a predictor of prognosis, 34 patients with untreated malignant lymphoma in the head and neck region were studied. After FDG-PET and treatment, they were observed from 15 to 50 months. Tumors which were aggressive and resistant to treatment tended to show high uptake of FDG. The survival rate of patients with high uptake of FDG, DAR > or = 8, was lower than the rate of the other patients. It is considered to be useful to add FDG uptake of the tumor to other prognostic factors for predicting the prognosis.
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PMID:FDG-PET for predicting the prognosis of malignant lymphoma. 781 61

The need for prompt and detailed evaluation of cancers and their treatment is requiring increasingly sophisticated methodologies for in vivo assessment. Morphological detail as provided by CT and MRI has yielded significant advances in diagnostic medicine. In spite of such advances, the means of achieving the clinical goals of improved quality and quantity of life in many cancer patients remain elusive. It is becoming increasingly evident that only with the addition of complementary physiological and biochemical data will further advances occur. While neither in vivo morphological imaging with CT or MRI nor physiological imaging with PET or MRS can provide the resolution of microscopic or cellular level assessment, all can provide macroscopic or regional data. With PET, however, exploration of the kinetics or chemical processes occurring at the cellular level is providing a "biological resolution" not heretofore achieved with in vivo imaging. Application of this complementary morphological and biochemical diagnostic information will likely lead to significant advances in patient management in the immediate future, most of which would probably not be achievable using any individual technique. Efficacy studies should be performed, however, when introducing any new high-technology methodology into clinical practice. A number of retrospective and prospective trials on PET applications in clinical oncology are ongoing sponsored by organizations such as the Institute for Clinical PET and the Western PET Association. Detailed studies also are underway to estimate the "cost" of delivery of PET services to the community (146). Numerous PET feasibility studies in animal models have demonstrated that no one radiotracer serves as the best agent for tumor imaging in all cases. Such studies with radiolabeled amino acids, sugars, and nucleoside derivatives, representatives of the major classes of biomolecules, have demonstrated variable tumor uptake dependent on such parameters as the type of cancer, organ of origin, animal host, and chemical structure of the radioligand. Detailed analysis of tracer uptake using multiple ligands in a variety of animal tumor models and clinical patients suggests that while given types of cancers may be better imaged with certain radiotracers, the use of multitracer imaging provides the specific details necessary for appropriate interpretation of tumor status. In addition, in cases where the diagnosis is uncertain, such information could have a significant impact on patient management by reducing the diagnostic differential. In spite of the many successes achieved with FDG in brain tumor imaging, the most well-known example of the problems that can arise with PET image interpretation is with the use of this agent.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Introduction to imaging brain tumor metabolism with positron emission tomography (PET). 787 78

Murine RSV-M glioma cells were genetically labeled with a retroviral BAG vector carrying the Escherichia coli beta-galactosidase gene. The X-gal-positive stable cell line RSV-M/BAG was obtained by the FDG-FACS method. To examine the behavior of glioma cells in the brain, we homografted RSV-M/BAG cells into the brain of C3H/HeN mice as cell suspensions. Individual grafted glioma cells were easily detected by histochemical staining for B-galactosidase (beta-gal). Three days after grafting, the beta-gal-positive cells were mainly found in the subependymal zone of the lateral ventricle. In addition, some solitary labeled cells were found at locations distant from the injection sites. On the seventh day after implantation, tumor masses were observed and graft-derived glioma cells were migrating bilaterally along the fibers in the corpus callosum. Other labeled cells extended into the brain parenchyma via the perivascular (Virchow-Robin) spaces. Rapid and extensive migration of individual glioma cells was thus clearly demonstrated by intracerebral transplantation of RSV-M/BAG cells.
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PMID:Migration of genetically labeled glioma cells after implantation into murine brain. 793 73

Positron emission tomography (PET) of the brain and heart has made important contributions in clinical and research applications in the fields of neurology and cardiology. The more recent applications of PET in tumor imaging has marked oncology as the next frontier in PET; however, the dilemma of rising health care cost will challenge the application of new technologies. This challenge can be approached by innovative and appropriate use of sophisticated technology in both the research and clinical realms. The current developments of PET imaging technology to accurately stage the extent of tumor, as well as monitor the effectiveness or ineffectiveness of new or current therapies will be an extremely valuable tool in research and in the cost effective management of cancer patients. In the future, the oncologist may be able to adjust the chemotherapy to the tumor response based on PET imaging. In other situations, PET may be able to predict that no existing therapy will elicit a durable response, resolving the patients' and families' uncertainty of whether extreme therapeutic measures would have made a significant difference. This paper reviews some of the recent developments and areas of research in tumor PET imaging, and describes some of the practical and technical aspects involved with FDG tumor quantitation and whole body PET imaging.
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PMID:Basic principles of positron emission tomography in oncology: quantitation and whole body techniques. 794 98

Positron emission tomography (PET) is just beginning to emerge as a clinically useful tool in the thorax. Imaging with FDG is used primarily to differentiate benign from malignant abnormalities, including solitary pulmonary nodules, staging bronchogenic carcinoma, and differentiating recurrent tumor from fibrosis following treatment. This article discusses the fundamental properties of PET images, techniques, and current clinical indications in the thorax.
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PMID:Positron emission tomography imaging of the thorax. 798 Jul 69


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