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

Three patients with primary breast sarcoma showed intense F-18 FDG breast uptake on the whole-body scan. In two patients the uptake was irregular and associated with cold foci that corresponded to hypodense lesions noted on the chest CT; these represented areas of pathologically demonstrated tumor necrosis. There was also intense FDG uptake in pulmonary, axillary, and supraclavicular lymph node metastases. All lesions were confirmed by CT scan of the chest. Thus F-18 FDG positron emission tomographic scanning accurately staged the tumors in these two patients, and it documented local recurrence in the third patient. Histopathologic examination showed evidence of a high-grade sarcoma, a primary rhabdomyosarcoma, and a malignant cystosarcoma phyllodes of the breast. Similar to breast carcinoma, F-18 FDG whole-body positron emission tomographic imaging could be useful in diagnosing and staging primary breast sarcomas.
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PMID:F-18 FDG whole-body positron emission tomography scan in primary breast sarcoma. 973 83

Chemotherapeutic or radiotherapeutic regimens are being increasingly used in low grade glioma of childhood. These protocols require methods to monitor tumor activity. We report our experience in eleven patients. The tumors were localized in the optic pathway (3), cerebral cortex (4) and thalamus/hypothalamus (4). Histological diagnoses included low grade astrocytoma (6), gliofibroma (1) and ganglioglioma (2). Two children with neurofibromatosis type 1 (NF-1) and typical optical tumors were not biopsied. 13 episodes of progression were noted including 3 altered diagnoses. This was evident from clinical symptoms in 11/13 episodes, computed tomography (CT) or magnetic resonance imaging (MRI) in 10/13 situations, iodine-123-alpha-methyltyrosine (123I-IMT) single-photon emission computed tomography (SPECT) in 10/10 situations, fluorine-18 fluorodesoxyglucose (18F-FDG) positron emission tomography (PET) in 0/3 and thallium-201 (201Tl) SPECT in 1/1. Seven responses to chemotherapy were recorded. Clinical symptoms indicated this in 7/7 situations, MRI in 5/7, 123I-IMT SPECT in 1/2 and 201Tl SPECT in 1/1. These data suggest that 123I-IMT SPECT is a valuable addition to low grade glioma diagnostic and stress the need for a prospective study.
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PMID:Monitoring tumor activity in low grade glioma of childhood. 974 59

Decision tree analysis was used to assess cost-effectiveness of chest FDG-PET in patients with a pulmonary tumor (non-small cell carcinoma, < or = Stage IIIB), based on the data of the current decision tree. Decision tree models were constructed with two competing strategies (CT alone and CT plus chest FDG-PET) in 1,000 patient population with 71.4% prevalence. Baselines of FDG-PET sensitivity and specificity on detection of lung cancer and lymph node metastasis, and mortality and life expectancy were available from references. Chest CT plus chest FDG-PET strategy increased a total cost by 10.5% when a chest FDG-PET study costs 0.1 million yen, since it increased the number of mediastinoscopy and curative thoracotomy despite reducing the number of bronchofiberscopy to half. However, the strategy resulted in a remarkable increase by 115 patients with curable thoracotomy and decrease by 51 patients with non-curable thoracotomy. In addition, an average life expectancy increased by 0.607 year/patient, which means increase in medical cost is approximately 218,080 yen/year/patient when a chest FDG-PET study costs 0.1 million yen. In conclusion, chest CT plus chest FDG-PET strategy might not be cost-effective in Japan, but we are convinced that the strategy is useful in cost-benefit analysis.
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PMID:[Decision tree sensitivity analysis for cost-effectiveness of chest FDG-PET in patients with a pulmonary tumor (non-small cell carcinoma)]. 975 18

Fluorine-18-fluorodeoxyglucose (F-18 FDG) PET was used to evaluate early-stage larynx cancer before and after radiotherapy. Less radical salvage surgery might be possible after timely diagnosis of recurrent or persistent tumor after radiotherapy. Eight patients with early-stage laryngeal cancer (two carcinoma in situ; six stage T1: tumor limited to vocal cords with normal mobility) underwent irradiation for potential cure. Five patients had pre- and postradiotherapy F-18 FDG PET, and three had postradiotherapy F-18 FDG PET only. All patients underwent a CT scan of the neck at the time of the F-18 FDG PET scan. One patient had a positive result of postradiotherapy F-18 FDG PET but a negative result of a CT of the neck, and biopsy revealed recurrent squamous carcinoma. Seven patients who had negative results of postradiotherapy F-18 FDG PET were free of disease at the 15-month median follow-up evaluation. (Three of them had no cancer on biopsy of the larynx, and four others were followed with periodic endoscopic examinations that revealed complete disappearance of the tumor.) F-18 FDG PET scan may be useful for earlier diagnosis of recurrent or persistent laryngeal cancer after radiotherapy and is preferable to repeated biopsies, which would traumatize radiation-damaged tissues. A prompt early diagnosis of failure of radiotherapy will lead to less radical salvage surgery.
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PMID:F-18 FDG PET scan after radiotherapy for early-stage larynx cancer. 981 62

With the variety of radiopharmaceutical agents and refined imaging techniques, thyroid and parathyroid imaging provides much valuable clinical information. The use of imaging is most important in the follow-up of differentiated (DTC) and medullary thyroid cancer (MTC). Patients with DTC are followed with serum thyroidglobulin and 131I whole body scintigraphy when the serum thyroglobulin level is elevated. When the 131I scintigram is negative, 201Tl scintigraphy may best identify the site of recurrent DTC. Alternative radioisotopes, ultrasound, CT, and FDG PET are also useful in localizing the site of DTC metastases. MTC recurrences and metastases are more difficult to image. Selective venous catheterization is the most sensitive and specific method for detecting areas of recurrent MTC. High-resolution ultrasound, CT, MR imaging, and scintigraphy are all capable of, and useful in, detecting macroscopic foci of metastatic tumor. Somatostatin receptor scintigraphy and 99mTc DMSA have been the most frequently used nuclear imaging agents in patients with recurrent MTC. Imaging for hyperparathyroidism remains controversial. Sestambi has become the preferred isotope for parathyroid scintigraphy; whereas high-resolution ultrasound is also frequently used. Preoperative imaging is being used as a method to allow a unilateral neck exploration, more recently, in conjunction with intraoperative 1-84 PTH assay and with intraoperative use of the gamma probe. Most often, parathyroid imaging is performed before reoperation for persistent hyperparathyroidism.
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PMID:The use of imaging studies in the diagnosis and management of thyroid cancer and hyperparathyroidism. 982 66

The evaluation of brain tumor recurrence and therapy-induced benign changes following surgery and/or irradiation is a diagnostic challenge for imaging methods based on either morphology (cCT/MRI) or function (SPECT/PET). Current literature and the present data of our own patients demonstrate the diagnostic efficiency of IMT-SPECT and FDG-PET in the detection of recurrence and in-vivo grading. Thirty-nine patients suspected of brain tumor recurrence at follow-up were studied by FDG-PET and IMT-SPECT. Thirty-four of 39 patients showed recurrences; in 12 cases even a change in the grade of malignancy was observed. All high-grade recurrences could be confirmed by either methods. IMT-SPECT showed a higher sensitivity in detecting low-grade tumors at recurrence. In contrast to IMT-SPECT, FDG-PET supports sufficient in-vivo grading. Both methods can be used to differentiate between tumor recurrence and radionecrosis. In conclusion the results of our study demonstrate the efficiency of IMT-SPECT and FDG-PET in confirming recurrences and determining the actual tumor grade.
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PMID:[Contribution of nuclear medicine to the diagnosis of recurrent brain tumors and cerebral radionecrosis]. 986 52

We studied the possible correlation between 2-18F-2-deoxy-D-glucose (FDG) uptake and histopathological findings in mass lesions of the parotid gland. Thirteen pleomorphic adenomas of the parotid gland were evaluated by computed tomography (CT), magnetic resonance imaging (MRI), Gallium scintigraphy, Technetium scintigraphy and FDG-positron emission tomography (PET). Standardized uptake values (SUV) and time-activity curves (TAC) were determined for all mass lesions. Pleomorphic adenomas were histologically classified into the following three types: epithelial, intermediate and mesenchymal, based on their dominant histological components. The numbers of epithelial, intermediate, and mesenchymal types were 5, 2, and 6, respectively. The levels of SUVs were 4.02 +/- 1.91 (range: 1.97-7.07) in the epithelial type, 5.05 +/- 1.12 (range: 4.26-5.58) in the intermediate type and 3.98 +/- 7.74 (range: 1.98-7.74) in the mesenchymal type, respectively. The accumulation of FDG did not differ significantly among the three types. Since the accumulation of FDG was significantly correlated with the tumor size, FDG-PET could reflect tumor growth ability more apparently than the other nuclear or imaging modalities.
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PMID:Positron emission tomographic imaging of pleomorphic adenoma in the parotid gland. 987 24

Thallium-201 chloride (201Tl) single-photon emission computed tomography (SPECT) detects a high percentage of histologically and anatomically diverse pediatric brain tumors. Thallium-201 chloride SPECT and F-18 fluoro-deoxy-glucose (18F-FDG) positron emission tomography (PET) are the most commonly used radionuclide techniques in neuro-oncology. Having developed a methodology to image 18F-FDG with SPECT, the authors performed SPECT scans coupled with magnetic resonance imaging to assess the comparative sensitivity of 201Tl and 18F-FDG in 19 children with brain tumors. Tumors were detected using 201Tl SPECT in 14 of 19 patients. Five of five postoperative residual tumors were detected by 201Tl SPECT, and six of seven after irradiation recurrences were detected. F-18 fluoro-deoxy-glucose SPECT detected tumors in only three of 19 patients, all of whom had abnormal 201Tl studies (all three after therapy recurrences). Thallium-201 chloride SPECT could be interpreted in 18 of 19 patients without magnetic resonance imaging confirmation, but none of the 19 18F-FDG SPECT studies could be interpreted without magnetic resonance imaging. Thallium-201 chloride SPECT is more sensitive than 18F-FDG SPECT in the detection of primary or recurrent childhood brain tumors. The failure of 18F-FDG SPECT in follow-up after therapy is primarily a problem of limited fluoro-deoxy-glucose uptake, not spatial resolution. Thallium-201 chloride SPECT is a promising imaging modality in neuro-oncology.
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PMID:Comparative value of thallium and glucose SPECT imaging in childhood brain tumors. 988 Jan 39

The capabilities and limitations of two-(2D) and three-dimensional (3D) fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting small tumors and lymph nodes were studied in a phantom modeling the human chest and axilla. Multiple dual-radionuclide phantom studies were performed. Five hollow spheres ranging in diameter from 3 mm to 15 mm were filled with carbon-11 and placed in the axillary and mediastinal regions of an anthropomorphic phantom containing hollow organs filled with 18F to simulate FDG uptake 1 h after injection. Dynamic imaging was performed to acquire PET images with varying target-to-background ratios. Imaging was performed in 2D and 3D acquisition modes, with and without attenuation correction, on a modern PET scanner. Lesion detectability was visually and quantitatively assessed. For objects larger than 9 mm in diameter, target-to-background ratios ranging from approximately 3:1 to approximately 10:1 were detectable. Objects < 9 mm in diameter required a target-to-background ratio of >/=18:1. Target-to-background ratios required for lesion detectability were equivalent for 2D and 3D PET images with and without attenuation correction. In conclusion, 2D and 3D PET with attenuation correction consistently detected "tumors" >/= 9 mm. Lesions < 9 mm could be detected if there was high enough tumor uptake. No statistically significant differences in lesion detection were found for 2D versus 3D PET, or for attenuation-corrected versus non-attenuation-corrected images.
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PMID:Capabilities of two- and three-dimensional FDG-PET for detecting small lesions and lymph nodes in the upper torso: a dynamic phantom study. 1042 8

Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) has proven useful in the differentiation of various tumour entities, including breast cancer. In patients with primary breast cancer we performed a 3-h imaging protocol to examine possible improvements in tumour detectability and image contrast. Twenty-nine patients with primary breast cancer with a diameter of >/=2 cm that was demonstrated to be malignant by biopsy or surgery were injected with 370-740 MBq 18F-FDG and scanned in the prone position. Data were acquired 0-40 min, 1.5 h and 3.0 h after injection. After correction for measured attenuation, decay and scatter and iterative reconstruction, standardised uptake values (SUVs) and tumour-to-non-tumour and tumour-to-organ ratios were calculated. Visual analysis was performed using transverse, sagittal and coronal slices as well as 3D reprojection images. Tumour-to-non-tumour and tumour-to-organ ratios were significantly higher for the 3-h images than for the 1.5-h images. SUVs did not increase to the same extent. Lesion detectability was 83% in 1.5-h images compared to 93% in 3-h images. We conclude that tumour contrast in breast cancer is improved by starting the PET acquisition at 3 h p.i. rather than at 1.5 h p.i.
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PMID:Optimal scan time for fluorine-18 fluorodeoxyglucose positron emission tomography in breast cancer. 1007 12


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