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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scanning has been useful in the management of various cancers. The normal glucose use of gray matter often limits the detection of metastatic lesions to the brain and skull with FDG PET. The authors report two cases of calvarial metastases: one with pheochromocytoma and the other with non-small-cell lung carcinoma. These cases illustrate the crucial role that FDG PET can play when patients are examined for metastases. The important concept of contrast resolution that is achieved with PET imaging is discussed as an advantage that significantly overcomes its limited spatial resolution in detecting small lesions that may not be detected by anatomic imaging techniques with high spatial resolution.
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PMID:Detection of cranial metastases by F-18 FDG positron emission tomography. 1131 19

Many isotopes are available for imaging patients with suspected thyroid cancer recurrence and metastases. TSH-stimulated low-dose 131I whole-body scanning with serum thyroglobulin either by standard LT4 withdrawal or rhTSH stimulation is the preferred test for monitoring patients without palpable disease or elevated serum thyroglobulin on LT4 therapy (Fig. 5). This approach has the advantage of finding disease that may be amenable to 131I therapy, although low-dose 131I scans are less sensitive than are scans with other imaging agents. 123I has better imaging characteristics than 131I and has been shown to be equivalent or superior to low-dose 131I in recent studies. As the availability of 123I increases and the cost decreases, this agent may replace 131I in imaging for recurrent or metastatic thyroid cancer. Patients who have an elevated serum thyroglobulin on LT4 therapy or after TSH stimulation but have a negative low-dose 131I scan require other imaging procedures to find the suspected disease. The authors currently perform a sensitive neck ultrasound to look for surgically remediable disease and consider a noncontrast CT scan of the chest to look for small pulmonary metastases that poorly concentrate low doses of 131I (Fig. 5). Fluoro-18-deoxyglucose PET, 99mTc MIBI, 201Tl, and 99mTc tetrofosmin are primarily useful in the setting of a negative whole-body 131I scan and elevated serum thyroglobulin. 18FDG-PET seems to have the highest sensitivity in this setting and would be the preferred imaging agent, but availability and cost are major issues (Fig. 5). Although some researchers have advocated these radiopharmaceuticals as first-line agents replacing 131I, there is little support for this position. This approach to imaging is not cost-effective because positive scans in these patients would most likely require 131I scintigraphy to determine whether the lesions are amenable to radioiodine therapy. 99mTc pertechnetate, 99mTc furifosmin, and somatostatin receptor scintigraphy have a limited role in imaging for recurrent or metastatic differentiated thyroid carcinoma. In choosing among 99mTc MIBI, 201Tl, and 99mTc tetrofosmin, the technetium label of sestamibi and tetrofosmin results in better image quality and faster imaging than 201Tl. Although 99mTc sestamibi and 99mTc tetrofosmin have not been compared in a large series, the higher tumor-to-background ratio and consistently high sensitivities of 99mTc tetrofosmin suggest that it could potentially have additional value over 99mTc sestamibi, but there is still limited experience with 99mTc tetrofosmin.
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PMID:Isotope imaging for metastatic thyroid cancer. 1144 71

Fluorine-18 fluorodeoxyglucose (F-18 FDG) has been used to evaluate early-stage larynx cancer and metastases of thyroid cancer. However, elevated F-18 FDG uptake in laryngeal muscles may lead to misinterpretation. In this report, three patients with thyroid cancer are described who had thyroid surgery 2 months to 1 year before F-18 FDG positron emission tomographic imaging. Various degrees of moderate to intense uptake were observed in their laryngeal regions. In one patient, this was caused by laryngeal muscle uptake. To determine the origin of the increased muscle uptake in the other two patients, the authors analyzed the position and shape of the foci of high uptake in light of the patients' clinical histories and other imaging results.
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PMID:Elevated F-18 FDG uptake in laryngeal muscles mimicking thyroid cancer metastases. 1145 75

A 64-year-old man with a history of large-cell lung carcinoma and recent resection of a brain metastasis was examined because of a general decline in his ability to function. Whole-body positron emission tomography with fluorine-18 fluorodeoxyglucose (FDG PET) showed metastases along the spinal cord that were confirmed with MRI. Intramedullary spinal cord metastasis occurs rarely, and the prognosis is extremely poor. Whole-body FDG PET allows the entire spinal cord to be examined noninvasively compared with magnetic resonance imaging, computed tomography, and myelography.
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PMID:Leptomeningeal carcinomatosis and intramedullary spinal cord metastases from lung cancer: detection with FDG positron emission tomography. 1159 39

A rapidly emerging clinical application of positron emission tomography (PET) is the detection of tumor tissue at whole-body studies performed with the glucose analogue 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). High rates of recurrence after partial hepatic resection in patients with colorectal cancer liver metastases indicate that current presurgical imaging strategies are failing to show extrahepatic tumor deposits. Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the lungs, it is particularly useful for identification and characterization of extrahepatic disease. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Several sources of benign and physiologic increased activity at FDG PET emphasize the need for careful correlation with findings of other imaging studies and clinical findings. FDG PET can improve the selection of patients for partial hepatic resection and thereby reduce the morbidity and mortality associated with inappropriate surgery.
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PMID:Selection of patients for resection of hepatic metastases: improved detection of extrahepatic disease with FDG pet. 1159 48

We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma ( n=1) and high-grade dysplasia ( n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6+/-3.5, CHOL 5.5+/-2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data.
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PMID:Carbon-11 choline or FDG-PET for staging of oesophageal cancer? 1173 25

The basis of tumour imaging with PET is a specific uptake mechanism of positron emitting radiopharmaceuticals. Among the potential tracers for breast cancer (fluorodeoxyglucose, methionine, tyrosine, fluoro-estradiol, nor-progesterone), 2-deoxy-2-fluoro-D-glucose labelled with fluorine (FDG) is the most widely used radiopharmaceutical because breast cancer is particularly avid of FDG and 18F has the advantages of a relatively long physical half-life. Mammography is the first choice examination in studying breast masses, due to its very good performances, an excellent compliance and the best value regarding the cost/effectiveness aspects. However FDG-PET revealed to be effective in the study of patients with ambiguous mammographies. The FDG uptake in tissue correlates with the histological grade and potential aggressiveness of breast cancer and this may have prognostic consequences. Besides the evaluation of breast lesions, FDG-PET shows a great efficacy in staging lymph node involvement prior surgery and this could have a great value in loco-regional staging. Whole body PET provides also information with regard to metastasis localizations both in soft tissue and bone, and plays an important clinical role mainly in detecting recurrent metastatic disease. In fact for its metabolic characteristics PET visualizes regions of enhanced metabolic activity and can complements other imaging modalities based on structural anatomic changes. Even though CT and MRI show superior resolution characteristics, it has been demonstrated that PET provides more accurate information in discriminating between viable tumour, fibrotic scar or necrosis. Several clinical evidences demonstrated that FDG-PET is also able to predict wether cancer will respond to the therapy, or, when applied at the end of the treatment, it can assess the response to the therapy. These statements are coming from the examination of more than 2000 breast cancer patients included in 88 articles or abstracts on studies in which FDG-PET was used for breast cancer detection.
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PMID:PET imaging in breast cancer. 1178 17

Cases of recurrence of breast cancer can pose considerable diagnostic and therapeutic challenges for the oncologic team. The prognosis and management decisions are based on knowledge of the true extent of disease. Conventional staging methods, including physical examination, assessment of levels of tumor markers, cross-sectional imaging, and bone scintigraphy, may not reliably demonstrate the extent of disease in all cases. Physical examination and cross-sectional imaging (computed tomography [CT] or magnetic resonance imaging) can be problematic because (a) the sequelae of previous surgery and radiation therapy can be difficult to distinguish from recurrent neoplasms and (b) early metastatic disease (small lesions) can be difficult to distinguish from benign lesions that are too small to characterize. Positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) can help clarify inconclusive findings from physical examination and cross-sectional imaging. FDG PET is more sensitive than CT in detection of lymphatic spread of disease to locoregional and mediastinal nodes. Metastases at distant sites including the lung, bone, and the liver are also readily detected at FDG PET. FDG PET has been proved accurate in restaging cases of recurrent breast cancer and will likely aid in directing therapy in these cases.
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PMID:Detection of locoregional and distant recurrences in breast cancer patients by using FDG PET. 1179 93

Thallium-201 (Tl-201) single photon emission computed tomography (SPECT) is funded for evaluation of malignancy in Australia and may have utility for staging of non-small cell lung cancer (NSCLC) if CT results are equivocal. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) is superior to CT for staging NSCLC but is more expensive and less widely available than Tl-201 SPECT. Therefore, these techniques were prospectively compared in 27 radical radiation therapy candidates. Patients were allocated a conventional, PET and Tl-201 stage. Tumour to background ratios (TBR) were recorded for the primary on both techniques. Metastatic disease was confirmed by surgical pathology, serial imaging or clinical follow up. Tumour to background ratios were consistently higher for FDG PET than Tl-201 SPECT (P < 0.0001). Positron emission tomography detected all known primary tumours but Tl-201 failed to image four primary tumours (15%). In 10 of 18 cases of discordance between PET and Tl-201 SPECT regarding stage, corroboration was available from pathology or disease progression. Positron emission tomography was shown to have a 100% positive predictive value, including all three patients with PET-detected distant metastases (P=0.002). Results indicate that PET is superior to Tl-201 SPECT scanning in the staging of NSCLC for radical radiation therapy, and that the low sensitivity for detection of local and metastatic disease is likely to limit the clinical impact and cost-effectiveness of this technique despite its lower cost.
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PMID:Imaging with F-18 FDG PET is superior to Tl-201 SPECT in the staging of non-small cell lung cancer for radical radiation therapy. 1190 82

This retrospective study was designed to assess the accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in diagnosing recurrence of gastric cancer. Thirty-three patients who had received surgical treatment for gastric cancer with curative intent and who had subsequently undergone FDG-PET for suspected recurrence were retrieved from the PET database. All patients were reviewed with full knowledge of prior conventional diagnostic work-up. Results were compared with a gold standard, consisting of histological confirmation or radiological and clinical follow-up. The gold standard established disease recurrence in 20/33 patients (prevalence 61%). Sensitivity and specificity of FDG-PET for the diagnosis of recurrence were 70% (14/20) and 69% (9/13), respectively. Positive and negative predictive values were 78% (14/18) and 60% (9/15), respectively. Of the six false-negative cases, all had intra-abdominal lesions (three had generalised abdominal metastases, one liver metastasis, one local recurrence and one ovarian metastasis). In the subgroup with previous signet cell differentiation of the primary tumour ( n=13, disease prevalence 62%), sensitivity was 62% (5/8) and specificity, 60% (3/5). Survival analysis for the entire patient group using Kaplan-Meier statistics yielded a longer survival in the PET-negative group (mean+/-SD, 21.9+/-19.0 months) than in the PET-positive group (mean+/-SD, 9.2+/-8.2 months) ( P=0.01). In the patient group with proven recurrence ( n=20), the mean survival for the PET-negative group was 18.5 (+/-12.5) months, as compared with 6.9 (+/-6.5) months for the PET-positive group ( P=0.05). Because of its poor sensitivity and low negative predictive value, FDG-PET is not suited for screening purposes in the follow-up of treated gastric cancer. However, FDG-PET appears to provide important additional information concerning the prognosis of recurrent gastric cancer.
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PMID:Whole-body PET with FDG for the diagnosis of recurrent gastric cancer. 1191 91


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