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Markus Schwaiger

Publications and source records attributed to Markus Schwaiger.

At least 127 records · Page 7Linked to original sources
PubMed2002

O-(2-[(18)F]Fluoroethyl)- L-tyrosine (FET): a tracer for differentiation of tumour from inflammation in murine lymph nodes.

High uptake of [(18)F]fluoro-2-deoxy- D-glucose (FDG) by inflammatory cells is a frequent cause of false positive results in lymph node (LN) staging by positron emission tomography. Previous studies suggest that radiolabelled amino acids may be more specific markers for viable tumour tissue than FDG. The aim of this study was to investigate quantitatively the uptake of FDG, [(3)H]methyl- L-methionine (MET) and O-2-([(18)F]fluoroethyl)- L-tyrosine (FET) in tumour-infiltrated and immunologically stimulated LNs. Popliteal LNs of Balb/c and DBA/2 mice were stimulated by injection into the right posterior foot pad of mice of either streptozotocin (STZ), causing chronic lymphadenitis, or concanavalin A (Con A), resulting in acute lymphadenitis. Tumour-infiltrated popliteal LNs were induced by inoculation of 2x10(5) lacZ-tagged T cell mouse lymphoma cells into the right posterior foot pad of syngeneic mice. Twenty-one days post inoculation of tumour cells or at various time points after STZ or Con A injection, mice were simultaneously injected intravenously with MET and FDG or MET and FET. After 30 min, mice were sacrificed and tracer uptake was determined in popliteal LNs. Contralateral LNs and LNs of untreated mice served as controls. Histopathological and immunohistochemical analysis demonstrated typical signs of chronic inflammation (non-specific sinus hyperplasia with macrophages) in STZ-treated animals and acute inflammatory changes (accumulation of neutrophilic granulocytes, vascular dilation, follicular hyperplasia) in Con A-treated animals. X-Gal staining confirmed the presence of tumour cells in the LNs of the injected side of tumour-inoculated mice. In the chronic lymphadenitis model, FDG uptake increased 3.0+/-0.1 fold [from 2.7+/-0.2 to 8.2+/-1.2 percent of injected dose per gram tissue (%ID/g)] and MET uptake 2.0+/-0.01 fold (from 4.5+/-0.6 to 9.2+/-1.1 %ID/g). In the acute lymphadenitis model, FDG uptake increased 3.9+/-0.3 fold (from 2.7+/-0.2 to 10.6+/-2.4 %ID/g) and MET uptake 1.9+/-0.1 fold (from 4.5+/-0.6 to 8.5+/-1.4 %ID/g). In contrast, FET uptake in both lymphadenitis models (1.0+/-0.03 and 1.2+/-0.04 fold) was not significantly different from that in controls (from 4.2+/-0.3 to 4.7+/-0.7 and to 5.1+/-0.4 %ID/g, respectively). Uptake of all three tracers in tumour-infiltrated LNs was significantly higher than that in control LNs. FDG uptake increased 2.8+/-0.15 fold (from 2.7+/-0.2 to 7.6+/-1.3%ID/g), MET uptake 1.7+/-0.11 fold (from 4.5+/-0.6 to 7.5+/-1.3 %ID/g) and FET uptake 2.4+/-0.15 fold (from 4.2+/-0.3 to 10.0+/-1.8 %ID/g). MET and FDG uptake was similar or higher in inflammatory than in tumour-infiltrated LNs ( P=0.01 and P<0.01, respectively). In contrast, uptake of FET showed no overlap between tumour-infiltrated and inflammatory LNs ( P<0.00001). In conclusion, tumour-infiltrated and inflammatory LNs could not be differentiated by means of FDG and MET uptake. FET, in contrast, proved to be a specific tracer for differentiating between tumour-infiltrated and inflammatory LNs in the murine models studied.

Animals↗
PubMed2002

Deferoxamine improves coronary vascular responses to sympathetic stimulation in patients with type 1 diabetes mellitus.

Effects of oxygen-derived free radicals are suggested to be a potential pathogenic factor for endothelial dysfunction. In this study we sought to evaluate the effect of hydroxyl radicals on the human coronary vascular bed in type I diabetes mellitus using positron emission tomography (PET). Thirteen patients with type 1 diabetes underwent PET using nitrogen-13 ammonia at rest and during sympathetic stimulation with the cold pressor test (CPT). The rest-stress study protocol was repeated twice (on different days) using pre-stress infusion of either saline as placebo or deferoxamine, an iron chelator which inhibits generation of hydroxyl radicals. At rest, global MBF was higher in diabetics than in normal controls (78.1+/-17.5 vs 63.2+/-14.9 mg 100 g(-1) min(-1), P<0.05) and myocardial vascular resistance (MVR) showed a trend towards lower values (patients, 1.28+/-0.35; controls, 1.55+/-0.32, P=NS). CPT increased MBF in all controls while 7/13 diabetics responded normally. CPT decreased MVR in 10/13 controls but in only 4/13 diabetics. There was no significant difference in the duration of diabetes, HbA1c, daily insulin dose, body mass index, or lipid profiles between patients with and patients without abnormal MBF or MVR responses. Pre-stress infusion of deferoxamine normalized MBF response in all six patients, and MVR response in six of the nine patients. Another group consisting of seven patients underwent a rest-rest protocol after infusion of deferoxamine and saline to investigate the effect of deferoxamine on resting MBF. Deferoxamine did not change the resting MBF (deferoxamine, 81+/-17 ml 100 g(-1) min(-1); saline, 75+/-19 ml 100 g(-1) min(-1), P=NS) or MVR (deferoxamine, 1.0+/-0.5 mmHg ml(-1) 100 g(-1) min(-1); saline, 1.2+/-0.6 mmHg ml(-1) 100 g(-1) min(-1), P=NS). In conclusion, inhibition of hydroxyl radical formation using deferoxamine significantly improved the responses of coronary microvasculature to sympathetic stimulation. Hydroxyl radicals may play a role in the pathogenesis of flow abnormalities in type 1 diabetes.

Ammonia↗
PubMed2002

Long-term consequences of switching handedness: a positron emission tomography study on handwriting in "converted" left-handers.

Until some decades ago, left-handed children who attended German schools were forced to learn to write with their right hand. To explore the long-term consequences of switching handedness, we studied the functional neuroanatomy of handwriting in 11 adult "converted" left-handers and 11 age-matched right-handers. All participants had used exclusively their right hand for writing since early childhood. Using [15O]H2O positron emission tomography, changes in normalized regional cerebral blood flow (rCBF) were assessed while participants repetitively wrote a stereotyped word with their right hand. The kinematics of handwriting did not differ between converted left-handers and right-handers. In innate right-handers, handwriting caused a preponderant left-hemispheric activation of parietal and premotor association areas. In contrast, converted left-handers demonstrated a more bilateral activation pattern with distinct activation foci in the right lateral premotor, parietal, and temporal cortex. Moreover, foci in the right rostral supplementary motor area and the right inferior parietal lobule demonstrated a positive linear relationship between the degree of "left-handedness" and normalized rCBF during right-hand writing. Functional activity in the primary sensorimotor cortex was not affected by handedness. Our findings provide evidence for persisting differences in the functional neuroanatomy of handwriting between right-handers and converted left-handers, despite decades of right-hand writing. Right-hemispheric activation in converted left-handers may reflect suppression of unwanted left-hand movements. Alternatively, this activity may represent persistent left-handedness and, as such, demonstrate a hemispheric asymmetry of hand movement representations in cortical motor association areas in relation to the direction and degree of handedness.

Acoustic Stimulation↗
PubMed2002

Myocardial salvage after coronary stenting plus abciximab versus fibrinolysis plus abciximab in patients with acute myocardial infarction: a randomised trial.

BACKGROUND: Patients with acute myocardial infarction might benefit from the addition of glycoprotein IIb/IIIa inhibitors to fibrinolytic or mechanical reperfusion strategies. We compared two strategies, stenting and fibrinolysis, both combined with abciximab, in terms of their ability to salvage myocardium in patients with acute myocardial infarction. METHODS: We enrolled 162 patients with acute myocardial infarction within 12 h of onset of symptoms, assigning 81 stenting plus abciximab and 81 alteplase plus abciximab. Technetium-99m sestamibi scintigraphy was done at admission and after a median of 11 days to calculate initial perfusion defect, final infarct size, and degree of myocardial salvage. The primary endpoint was the salvage index (the ratio of the degree of myocardial salvage to the initial perfusion defect). Major adverse clinical events within 6 months from randomisation were also compared between the two treatments. FINDINGS: Paired scintigraphic measurements were available for 70 patients in the stent group and 71 in the alteplase group. Stenting was associated with greater myocardial salvage than alteplase (median 13.6% [IQR 5.9-23.9] vs 8.0% [2.5-16.0] of the left ventricle; p=0.007). Salvage index was greater in the stent group than in the alteplase group (median 0.60 [0.37-0.82] vs 0.41 [0.13-0.58]; p=0.001). The 6-month mortality rate was 5% (four deaths) in the stent group and 9% (seven deaths) in the alteplase group (relative risk 0.56 [95% CI 0.17-1.88]; p=0.35). INTERPRETATION: In patients with acute myocardial infarction, a reperfusion strategy based on stenting with abciximab produced more myocardial salvage than the combination of fibrinolysis plus abciximab. Larger studies are needed to assess whether these effects translate into clinical benefit.

Abciximab↗
PubMed2002

PET imaging with [11C]methyl- L-methionine for therapy monitoring in patients with rectal cancer.

In this study we evaluated whether positron emission tomography (PET) using the amino acid [11C]methyl- L-methionine (MET) may be used for therapy monitoring in patients with rectal cancer who are undergoing preoperative chemoradiotherapy. A total of 41 MET-PET scans were performed in 26 patients with locally advanced rectal cancers. All patients were examined prior to chemoradiotherapy. In 15 patients, MET-PET was repeated after preoperative chemoradiotherapy (45 Gy radiation dose, 250 mg 5-fluorouracil as continuous infusion). MET uptake prior to and after the completion of chemoradiotherapy was correlated with changes in T stage and histopathological regression. All tumours were visualised with high contrast and had a significantly higher SUV (5.7+/-2.2) than normal rectum (2.7+/-0.9) and all other organs in the field of view except the small intestine (3.9+/-1.7). In all tumours studied prior to and after chemoradiotherapy, MET uptake decreased during therapy (SUV before therapy, 6.2+/-2.3; SUV after therapy, 2.6+/-1.2; P=0.0007). However, the degree of change in MET uptake was not correlated with histopathological tumour response. In conclusion, primary rectal cancer can be imaged with MET-PET. However, for the studied chemoradiotherapy regimen, MET-PET did not allow an assessment of the response to therapy.

Adult↗
PubMed2002

Assessment of coronary flow reserve: comparison between contrast-enhanced magnetic resonance imaging and positron emission tomography.

OBJECTIVES: The study compared flow reserve indices by magnetic resonance imaging (MRI) with quantitative measures of coronary angiography and positron emission tomography (PET). BACKGROUND: The noninvasive evaluation of myocardial flow by MRI has recently been introduced. However, a comparison to quantitative flow measurement as assessed by PET has not been reported in patients with coronary artery disease (CAD). METHODS: Two groups of healthy volunteers and 25 patients with angiographically documented CAD were examined by MRI and PET at rest and during adenosine stress. Dynamic MRI was performed using a multi-slice ultra-fast hybrid sequence and a rapid gadolinium-diethylenetriaminepenta-acetic acid bolus injection (0.05 mmol/l). Upslope and peak-intensity indices were regionally determined from first-pass signal intensity curves and compared to N-13 ammonia PET flow reserve measurements. RESULTS: In healthy volunteers, the upslope analysis showed a stress/rest index of 2.1 plus minus 0.6, which was higher than peak intensity (1.5 plus minus 0.3), but lower than flow reserve by PET (3.9 plus minus 1.1). Localization of coronary artery stenoses (> 75%, MRI < 1.2), based on the upslope index, yielded sensitivity, specificity and diagnostic accuracy of 69%, 89% and 79%, respectively. Upslope index correlated with PET flow reserve (r = 0.70). A reduced coronary flow reserve (PET < 2.0, MRI < 1.3) was detected by the upslope index with sensitivity, specificity and diagnostic accuracy of 86%, 84% and 85%, respectively. CONCLUSIONS: Magnetic resonance imaging first-pass perfusion measurements underestimate flow reserve values, but may represent a promising semi-quantitative technique for detection and severity assessment of regional CAD.

Adult↗
PubMed2002

Assessment of myocardial viability with contrast-enhanced magnetic resonance imaging: comparison with positron emission tomography.

BACKGROUND: Recent studies indicate that MRI, after administration of gadolinium-diethylenetriamine pentaacetic acid, can identify nonviable areas in dysfunctional myocardium. We compared MRI hyperenhancement with PET as a gold standard for detection and quantification of myocardial scar tissue. METHODS AND RESULTS: Thirty-one patients with ischemic heart failure (ejection fraction, 28+/-9%) were imaged with PET and MRI. Scar was defined as regionally increased MRI signal intensity 20 minutes after injection of 0.2 mmol/kg gadolinium-diethylenetriamine pentaacetic acid and as concordantly reduced perfusion and glucose metabolism as defined by PET. Sensitivity and specificity of MRI in identifying patients and segments (n=1023) with matched flow/metabolism defects was 0.96 of 1.0 and 0.86 of 0.94, respectively. Eleven percent of segments defined as viable by PET showed some degree of MRI hyperenhancement. Defect severity score based on visual analysis was 44.3+/-9.1 for PET and 47.6+/-11.1 for MRI (r=0.91, P<0.0001). Quantitatively assessed relative MRI infarct mass correlated well with PET infarct size (r=0.81, P<0.0001). Furthermore, MRI hyperenhancement was a better predictor of scar tissue than end-diastolic and end-systolic wall thickness or thickening. CONCLUSIONS: In severe ischemic heart failure, MRI hyperenhancement as a marker of myocardial scar closely agrees with PET data. Although hyperenhancement correlated with areas of decreased flow and metabolism, it seems to identify scar tissue more frequently than PET, reflecting the higher spatial resolution. Additional functional studies after revascularization are required to define the significance of small islands of scar detected by MRI.

Cell Survival↗
PubMed2002

Sensory system interactions during simultaneous vestibular and visual stimulation in PET.

The patterns of regional cerebral blood flow (rCBF) increases and decreases in PET were compared for unimodal vestibular, unimodal visual, and for simultaneous vestibular and visual stimulation. Thirteen healthy volunteers were exposed to a) caloric vestibular stimulation, b) small-field visual motion stimulation in roll, c) simultaneous caloric vestibular and visual pattern stimulation. Unimodal vestibular stimulation led to activations of vestibular cortex areas, in particular the parieto-insular vestibular cortex (PIVC), and concurrent deactivations of visual cortical areas [Brodmann area (BA) 17-19]. Unimodal visual motion stimulation led to activations of the striate visual cortex and the motion-sensitive area in the middle temporal/middle occipital gyri (BA 19/37) with concurrent deactivations in the PIVC. Simultaneous bimodal stimulation resulted in activations of the cortical representation of both sensory modalities. In the latter condition activations and deactivations were significantly smaller compared to unimodal stimulation. The findings are consistent with the concept of an inhibitory reciprocal vestibulo-visual interaction in all three stimulus conditions.

Adult↗
PubMed2002

Alterations of the sympathetic nervous system and metabolic performance of the cardiomyopathic heart.

Little is known about the effects of altered sympathetic innervation on the efficiency of the cardiomyopathic heart. Thus, it was the aim of this study to determine non-invasively the relationship between the metabolic cost of cardiac work and alterations of the sympathetic nervous system. In ten patients with chronic idiopathic dilated cardiomyopathy, left ventricular function and geometry were assessed by tomographic radionuclide angiography. Myocardial oxidative metabolism was quantified by the clearance constant k(mono) for carbon-11 acetate, determined by positron emission tomography (PET). Cardiac efficiency was then estimated by the work-metabolic index [WMI = stroke volume index x heart rate x systolic pressure/k(mono)]. Additionally, myocardial presynaptic sympathetic innervation was investigated in the same PET session using 11C-hydroxyephedrine, and plasma norepinephrine levels were determined by high-performance liquid chromatography. The WMI was 3.0+/-1.3 mmHg x ml x 10(6)/m2 and correlated significantly with left ventricular ejection fraction (19%+/-10%; r=0.66, P<0.04) and peripheral vascular resistance (3,638+/-1,085 dynes x s/cm5; r=-0.75, P<0.01). Cardiac hydroxyephedrine retention, reflecting integrity of presynaptic innervation, was abnormally low in 58%+/-38% of the left ventricle. Cardiac hydroxyephedrine retention (r=0.65, P<0.05) and plasma norepinephrine concentration (r=-0.80, P<0.01) both correlated significantly with the WMI. At multivariate stepwise linear regression, only plasma norepinephrine and peripheral vascular resistance were independent determinants of the WMI. In conclusion, metabolic performance of the cardiomyopathic heart decreases with increasing alterations of the sympathetic nervous system. Increasing afterload and effects of systemic sympathetic activation, however, seem to play a dominant role while direct alterations of cardiac presynaptic sympathetic innervation are not independently associated.

Acetic Acid↗
PubMed2002

Prominent hypometabolism of the right temporoparietal and frontal cortex in two left-handed patients with primary progressive aphasia.

Primary progressive aphasia (PPA) is characterized by progressive deterioration of language function with relative preservation of other cognitive functions. Previous studies based on neuroimaging and histology point to predominantly left temporal pathology in PPA patients. Here we report two left-handed subjects with typical symptoms of the nonfluent form of PPA in whom 18F-FDG PET revealed an asymmetric right-hemispheric pattern of reduced glucose metabolism in the frontal and temporoparietal cortex. These findings support the hypothesis that PPA can be considered as a symptom complex rather than a disease entity.

Aged↗
PubMed2002

The role of lateral premotor-cerebellar-parietal circuits in motor sequence control: a parametric fMRI study.

Functional characterisation of higher order motor systems can be obtained by modulating the processing demands imposed onto relevant motor circuitries. Here we performed whole-brain functional magnetic resonance imaging (fMRI) and parametric statistical analyses in eight healthy volunteers to study task-related recruitment of motor circuits associated with unilateral finger movement sequences of increasing length and complexity, but with equal basic motor parameters. Statistical parametric mapping software was applied for analysis. Categorical analysis of the main effect of motor action showed cerebral activation in the established cortical and subcortical motor network. Parametric analyses of the blood-oxygen-level-dependent (BOLD) contrast revealed significant signal increases correlating to sequence length and complexity in a subset of activated areas, notably contralateral ventral and dorsal premotor cortex, bilateral superior parietal cortex, left inferior frontal gyrus/Broca's area, right dentate nucleus, and left visual association cortex. These data underscore the importance of ventral premotor-cerebellar-parietal circuits in processing length and complexity of sequential finger movements.

Adult↗
PubMed2002

From thallium scan to molecular imaging.

The diagnostic and prognostic evaluation of cardiovascular diseases has been improved considerably by the application of imaging procedures. Among many, scintigraphic procedures have emerged as important diagnostic tools to assess extent, severity, and prognosis in patients with coronary artery disease (CAD). For more than the last 30 years, however, the application of perfusion imaging has been extended to allow the combined evaluation of perfusion, perfusion reserve, and ventricular function. With positron emission tomography (PET), quantitative assessment of perfusion has become possible. In combination with pharmacological stress agents, the coronary flow reserve (CFR) can be quantitatively assessed as an early marker of endothelial dysfunction. PET in combination with metabolic tracers has added the evaluation of cardiac substrate metabolism, which has become an important clinical marker for ischemically jeopardized myocardium. The PET information is widely considered as the gold standard for tissue viability in the management of patients with advanced CAD and impaired left ventricular function (LVF). New tracer approaches include the assessment of cardiac innervation, which plays an increasingly recognized role in the pathophysiology of cardiac diseases. Radiolabeled catecholamine analogues provide visualization of sympathetic nerve terminals that are functionally altered in patients with diabetes mellitus and cardiomyopathy. In addition, this scintigraphic information allows the monitoring of physiological processes such as reinnervation of the transplanted heart. New methods, such as imaging of apoptosis and gene expression, are of interest in cardiology. Combining the therapeutic gene with a reporter gene, the transfection of cardiac tissue can be monitored noninvasively. First results employing the herpes simplex virus thymidine kinase reporter gene (HSV1-tk) are encouraging and represent an attractive approach for the use of PET imaging in the control of cardiac gene therapy.

Journal Article↗
PubMed2002

Long-term prevention of premature coronary atherosclerosis in homozygous familial hypercholesterolemia.

Homozygous familial hypercholesterolemia (FHH) leads to severe premature atherosclerosis. A 22-year-old woman with FHH has been treated with a combination of H.E.L.P. apheresis (heparin-mediated extracorporeal LDL precipitation) and statins for 15 years. The combined treatment maintained a plasma LDL-cholesterol reduction from baseline of 840 to 122 mg/dL (85% reduction). In addition, H.E.L.P. apheresis reduced the elevated lipoprotein(a) and fibrinogen levels by 60% to 70%. All xanthomata disappeared. There is no evidence of premature atherosclerosis studied by means of electron beam computed tomography and (13)N-ammonia positron emission tomography: The entire coronary vasculature is free of calcifications. Her myocardial blood flow at rest (87 mL/100 g/min) and during stress (308 mL/100 g/min) and the coronary flow reserve (3.5) are normal after H.E.L.P. treatment. This case demonstrates the efficacy and safety of the combined treatment of H.E.L.P. apheresis and statins even in serious cases of FHH.

Adult↗
PubMed2001

Comparison of radioiodinated TOC, TOCA and Mtr-TOCA: the effect of carbohydration on the pharmacokinetics.

Although somatostatin-based peptide receptor imaging (sst-PRI) and peptide receptor radiotherapy (sst-PRRT) of human endocrine tumours and their metastases has become a valuable method, the experience with radiohalogenated sst-directed peptides has so far been disappointing. To extend the broad spectrum of radiohalogens with suitable radionuclide properties for sst-PRI and PRRT, new strategies in ligand development are required. The major drawbacks to be overcome include fast hepatic uptake, high abdominal background activity and low tumour uptake. Recently we introduced radiolabelled glycated octreotides as a new series of sst-binding radiotracers with excellent physicochemical characteristics. In this study we compared [(125)I]Tyr(3)-octreotide ([(125)I]TOC, ( 1)), [(125)I]Tyr(3)-octreotate ([(125)I]TOCA, ( 2)) and a carbohydrated octreotide derivative, maltotriose-[(125)I]Tyr(3)-octreotate ([(125)I]Mtr-TOCA, ( 3)) to evaluate the effect of single C-terminal oxidation and simultaneous N-terminal carbohydration. The biodistribution was compared in nude mice bearing AR42J tumour xenografts. Compared with ( 1), activity uptake of ( 2) and ( 3) at 1 h was decreased in intestine [36% ( 2), 72% ( 3)], liver [62% ( 2), 79% ( 3)] and kidney [34% ( 2), 41% ( 3)], respectively. Blood clearance was fast for all compounds investigated. Using ( 1) as reference, tumour uptake of ( 2) and ( 3) was 3.8- and 4.3-fold higher at 1 h p.i. At 1 h the tumour-to-blood ratio of ( 3) was 28.2+/-7.3, and the tumour-to-muscle ratio, 147+/-48. Specificity of tumour uptake was demonstrated in AR42J tumour-bearing mice by pretreatment with 0.8 mg TOC/kg 5 min prior to injection of ( 3). In cells transfected with sst1-sst5, the binding profile of I-Mtr-TOCA revealed a very high affinity and selectivity for sst2. In a first scintigraphic [(123)I]Mtr-TOCA study of a patient with a carcinoid of the small intestine with known peritoneal carcinomatosis and a solitary liver metastasis, all tumour tissues, including the liver metastasis, were well defined and clearly visible as soon as 30 min p.i. Based on these encouraging findings we conclude that carbohydration is a powerful strategy for the development of new radiolabelled sst-binding peptides and may represent a general method to improve pharmacokinetics of other peptide radioligands. [(123)I]Mtr-TOCA is a very promising new candidate for sst-directed PRI.

Aged↗
PubMed1999

Utility of PET in Breast Cancer.

Breast cancer represents the most frequent malignant disease in women and the second leading cause of cancer death in western countries. Current available treatment includes surgery, radiation therapy, chemotherapy, and hormonal therapy. The disease is often curable when detected in early stages. Mammography is the most important screening modality; however, limitations of available procedures for the diagnosis and accurate staging of breast cancer has increased the application of metabolic imaging by positron emission tomography (PET). PET using the radiolabeled glucose analogue, F-18 fluorodeoxyglucose (FDG), enables visualization of increased glucose metabolism of malignant tissue. PET has been used successfully in an increasing number of oncological applications. It is an excellent clinical method to detect breast cancer over 1 cm in diameter and to accurately identify the extent of axillary lymph node metastases in patients with locally advanced disease. Recent reports have shown the high accuracy of FDG-PET imaging for staging of breast cancer patient by using whole-body PET imaging. The metabolic signal of tumor tissue allows for monitoring the effect of chemotherapy. FDG-PET can differentiate between responder and nonresponder early in the course of therapy. By identifying nonresponding patients, PET can help to avoid ineffective therapy and therefore, reduce toxic side effects in these patients.

Journal Article↗
PubMed1998

Positron Emission Tomography in Diagnosis and Therapy Monitoring of Patients with Lymphoma.

In contrast to conventional imaging modalities, positron emission tomography using fluorodeoxyglucose detects malignant tumors by their increased glucose metabolism. In patients with Hodgkin's disease or non-Hodgkin's lymphoma, FDG-PET imaging has been shown to sensitively identify enhanced tracer uptake in involved lymph nodes and infiltrated tissue. This brief review will summarize the currently available information on staging of lymphoma patients in comparison with other imaging modalities. In addition, FDG PET imaging has been suggested for differentiation of viable residual or recurrent tumor and scar after tumor therapy. One of the most promising applications of PET in the future will be the metabolic evaluation of early response to tumor therapy. It is hypothesized that changes in tumor metabolism occur before significant decrease of tumor mass. Early assessment of chemotherapy might help to avoid the toxicity of an ineffective therapy. In summary, the results concerning various clinical applications of PET imaging are encouraging for further prospective trials to document the advantage of PET in diagnosis and therapy of lymphoma patients as compared to conventional strategies.

Journal Article↗