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Biomedical subjects

S N Reske

Publications and source records attributed to S N Reske.

At least 37 records · Page 2Linked to original sources
PubMed2001

Fluorine-18 2-deoxy-2-fluoro-D-glucose PET in the preoperative staging of breast cancer: comparison with the standard staging procedures.

The present study compared the diagnostic accuracy of fluorine-18 2-deoxy-2-fluoro-D-glucose positron emission tomography (FDG-PET) with conventional staging techniques. The differentiation between malignant and benign lesions and the detection of multifocal disease, axillary and internal lymph node involvement, and distant metastases were evaluated. One hundred and seventeen female patients were prospectively examined using FDG-PET and conventional staging methods such as chest X-ray, ultrasonography of the breast and liver, mammography and bone scintigraphy. All patients were examined on a modern full-ring PET scanner. Histopathological analysis of resected specimens was employed as the reference method. The readers of FDG-PET were blinded to the results of the other imaging methods and to the site of the breast tumour. The sensitivity and specificity of FDG-PET in detecting malignant breast lesions were 93% and 75% respectively. FDG-PET was twofold more sensitive (sensitivity 63%, specificity 95%) in detecting multifocal lesions than the combination of mammography and ultrasonography (sensitivity 32%, specificity 93%). Sensitivity and specificity of FDG-PET in detecting axillary lymph node metastases were 79% and 92% (41% and 96% for clinical evaluation). FDG-PET correctly indicated distant metastases in seven patients. False-positive or false-negative findings were not encountered with FDG-PET. Chest X-ray was false-negative in three of five patients with lung metastases. Bone scintigraphy was false-positive in four patients. Three patients were upstaged since FDG-PET detected distant metastases missed with the standard staging procedure. It is concluded that, compared with the imaging methods currently employed for initial staging, FDG-PET is as accurate in interpreting the primary tumour and more accurate in screening for lymph node metastases and distant metastases. Due to a false-negative rate of 20% in detecting axillary lymph node metastases, FDG-PET cannot replace histological evaluation of axillary status.

Adult↗
PubMed2001

Validation of myocardial blood flow estimation with nitrogen-13 ammonia PET by the argon inert gas technique in humans.

We simultaneously determined global myocardial blood flow (MBF) by the argon inert gas technique and by nitrogen-13 ammonia positron emission tomography (PET) to validate PET-derived MBF values in humans. A total of 19 patients were investigated at rest (n = 19) and during adenosine-induced hyperaemia (n = 16). Regional coronary artery stenoses were ruled out by angiography. The argon inert gas method uses the difference of arterial and coronary sinus argon concentrations during inhalation of a mixture of 75% argon and 25% oxygen to estimate global MBF. It can be considered as valid as the microspheres technique, which, however, cannot be applied in humans. Dynamic PET was performed after injection of 0.8 +/- 0.2 GBq 13N-ammonia and MBF was calculated applying a two-tissue compartment model. MBF values derived from the argon method at rest and during the hyperaemic state were 1.03 +/- 0.24 ml min-1 g-1 and 2.64 +/- 1.02 ml min-1 g-1, respectively. MBF values derived from ammonia PET at rest and during hyperaemia were 0.95 +/- 0.23 ml min-1 g-1 and 2.44 +/- 0.81 ml min-1 g-1, respectively. The correlation between the two methods was close (y = 0.92x + 0.14, r = 0.96; P < 0.0001). No indication was found for limited extraction of ammonia in the myocardium. The high concordance of global MBF values derived with argon and ammonia indicates that the implicit correction of spillover and recovery effects, incorporated in the model by including an effective blood volume parameter, works correctly quantitatively. Our data provide the previously missing human validation of MBF measurements from 13N-ammonia PET.

Adenosine↗
PubMed2001

Targeted bone marrow irradiation in the conditioning of high-risk leukaemia prior to stem cell transplantation.

Disease recurrence following stem cell transplantation (SCT) remains a major problem. Despite the sensitivity of leukaemias to chemotherapy and irradiation, conventional conditioning before SCT is limited by significant organ toxicity. Targeted irradiation of bone marrow and spleen by radioimmunotherapy may provide considerable dose escalation, with limited toxicity to non-target organs. In this study, 27 patients with high-risk or relapsing leukaemia were treated with rhenium-188-labelled CD66a,b,c,e radioimmunoconjugates (188Re-mAb) specific for normal bone marrow in addition to conventional conditioning with high-dose chemotherapy and 12 Gy total body irradiation prior to SCT. A mean activity of 10.2+/-2.1 (range 6.9-15.8) GBq 188Re-mAb was administered intravenously. Acute side-effects were assessed according to the CTC classification and patient outcome was determined. Mean radiation doses (Gy; range in parentheses) to relevant organs and whole body were as follows: 13.1 (6.5-22) to bone marrow, 11.6 (1.7-31.1) to spleen, 5.0 (2.0-11.7) to liver, 7.0 (2.3-11.6) to kidneys, 0.7 (0.3-1.3) to lungs and 1.4 (0.8-2.1) to the whole body. Stem cells engrafted in all patients within 9-18 days post SCT. Acute organ toxicity of grade II or less was observed. During follow-up for 25.4+/-5.3 (range 18-34) months, 4/27 (15%) patients died from relapse, and 9/27 (33%) from transplantation-related complications. Fourteen patients (52%) are still alive and in ongoing complete clinical remission. Radioimmunotherapy with the bone marrow-seeking 188Re-labelled CD66 mAb can double the dose to bone marrow and spleen without undue extramedullary acute organ toxicity, when given in addition to high-dose chemotherapy and 12 Gy TBI before allogeneic SCT. This intensified conditioning regimen may reduce the relapse rate of high-risk leukaemia.

Adolescent↗
PubMed2001

FDG-PET for clinical use. Results of the 3rd German Interdisciplinary Consensus Conference, "Onko-PET III", 21 July and 19 September 2000.

Positron emission tomography (PET) is the most powerful molecular imaging technique currently available for clinical use. Because deranged tumour metabolism is a common finding in many malignancies, PET is frequently used for tissue characterisation, staging and therapy control. Four previous consensus studies in Germany, performed up to 1997, have established indications for fluorine-18 fluoro-2-deoxy-D-glucose (FDG) PET in oncology, neurology and cardiology. More than 10,000 references on FDG-PET have been published in the meantime, mostly on oncological issues. Therefore, it was the aim of the present paper to provide an update on the clinical use of FDG-PET in oncology. For this purpose a systematic literature search was performed in all common medical literature databases. All hits were manually checked and abstracts, case reports, technically oriented papers and reviews were excluded from analysis. A questionnaire comprising 24 items was developed for standardised quality assessment according to evidence-based medicine (EBM) criteria. We selected 533 papers for further review by an interdisciplinary panel of 58 experts from oncology, radiology and nuclear medicine. Clinical use was judged according to the following grading scheme: 1a, established clinical use; 1b, clinical use probable; 2, useful in individual cases; 3, not yet assessable owing to missing or incomplete data; 4, clinical use rare (either as inferred from theoretical considerations or as demonstrated by published studies). Of the 533 papers selected, 122 references with 7,092 documented patients fulfilled the EBM criteria for detailed review. The results of these studies were tabulated and are available at www.nucmed-ulm.de. Clinical indications (grade 1a or 1b) were established for differentiating benign from malignant lesions in pulmonary nodules, pancreatic masses and residual masses after chemotherapy in malignant lymphoma. Staging was improved by FDG-PET in oesophageal cancer, breast cancer, head and neck cancer, lung cancer, malignant lymphoma and malignant melanoma. Effectiveness of radio- and/or chemotherapy could be better controlled in Hodgkin's disease and high-grade non-Hodgkin's lymphoma. Restaging was improved in relapsing thyroid cancer, colorectal cancer, head and neck cancer, lung cancer and malignant melanoma. In summary, the efficiency of FDG-PET was studied in several thousand patients with malignant tumours and was found to be well documented in the international high-quality peer-reviewed literature. There are clear-cut clinical indications for FDG-PET in diagnosis, staging and therapy control, and the technique can help to improve the management of many patients with cancer.

Fluorodeoxyglucose F18↗
PubMed2001

Disturbed neural circuits in a subtype of chronic catatonic schizophrenia demonstrated by F-18-FDG-PET and F-18-DOPA-PET.

Permanent verbal, visual scenic and coenaestetic hallucinations are the most prominent psychopathological symptoms aside from psychomotor disorders in speech-sluggish catatonia, a subtype of chronic catatonic schizophrenia according to Karl Leonhard. These continuous hallucinations serve as an excellent paradigm for the investigation of the assumed functional disturbances of cortical circuits in schizophrenia. Data from positron emission tomography (F-18-FDG-PET and F-18-DOPA-PET) from three patients with this rare phenotype were available (two cases of simple speech-sluggish catatonia, one case of a combined speech-prompt/speech-sluggish subtype) and were compared with a control collective. During their permanent hallucinations, all catatonic patients showed a clear bitemporal hypometabolism in the F-18-FDG-PET. Both patients with the simple speech-sluggish catatonia showed an additional bilateral thalamic hypermetabolism and an additional bilateral hypometabolism of the frontal cortex, especially on the left side. In contrast, the patient with the combined speech-prompt/speech-sluggish catatonia showed a bilateral thalamic hypometabolism combined with a bifrontal cortical hypermetabolism. However, the left/right ratio of the frontal cortex also showed a lateralisation effect with a clear relative hypometabolism of the left frontal cortex. The F-18-DOPA-PET of both schizophrenic patients with simple speech-sluggish catatonia showed a normal F-18-DOPA storage in the striatum, whereas in the right putamen of the patient with the combined form a higher right/left ratio in F-DOPA storage was discernible, indicating an additional lateralized influence of the dopaminergic system in this subtype of chronic catatonic schizophrenia. Most likely, the prominent bitemporal F-18-FDG- hypometabolism in these chronic schizophrenic patients with speech-sluggish catatonia suffering from permanent continuous hallucinations, reflects a deficit in sensoric gating following prenatal cortical neurodevelopmental disturbances. However, the functional disturbances underlying hallucinations in "the schizophrenias" seem to be more complex; in different subtypes of the schizophrenic spectrum disorder hallucinations seem to be based on alterations in additional cortical and subcortical brain regions.

Adult↗
PubMed2001

Is a preoperative multidiagnostic approach to predict surgical resectability of periampullary tumors still effective?

BACKGROUND: Multimodality staging is recommended in patients with periampullary tumors to optimize preoperative determination of resectability. We investigated the potency of currently used diagnostic procedures in order to determine resectability. METHODS: Ninety-five consecutive patients with periampullary tumors prehospitally staged resectable underwent preoperative diagnostic tests: helical-computed tomography (CT) with maximum intensity projection of arterial vessels (MIP), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreaticography (MRCP), endoscopic ultrasonography (EUS), endoscopic retrograde cholangiopancreaticography (ERCP), digital subtraction angiography (DSA), and positron emission tomography (PET). Diagnoses were verified by surgery and histopathology. RESULTS: In 45 patients with benign and 50 patients with malignant periampullary tumors sensitivity for tumor diagnosis was 89% to 96% in CT, MRI, EUS, and PET. Small tumors were best diagnosed by EUS (100%). Diagnosis of malignancy was made with 85% (EUS), 83% (CT), 82% (PET), and 72% (MRI) accuracy. Arterial vessel infiltration was best predicted by CT/MIP with an accuracy of 85%. For venous vessel infiltration MRI reached 85% accuracy. Accuracy rates for local nonresectability were 93% (EUS), 92% (MRI), and 90% (CT). Two and 4 of 8 patients with distant metastases were identified by CT and PET, respectively. The correct diagnosis of malignancy and determination of resectability was made by CT in 71% and by MRI in 70%. Biliary stenting reduced accuracy of CT diagnosis of malignancy from 88% to 73%. CONCLUSIONS: CT obtained before stenting was the single most useful test, providing correct diagnosis in 88% and resectability in 71% of patients. If no tumor is depicted in CT, EUS should be added. Uncertain venous vessel infiltration can be verified by MRI or EUS. Angiography should no longer be a routine diagnostic procedure. Equivocal tumors or possible metastasis may be further examined with PET.

Ampulla of Vater↗
PubMed2001

Endovascular irradiation with the liquid beta-emitter Rhenium-188 to reduce restenosis after experimental wall injury.

OBJECTIVE: Postinterventional irradiation is a new therapeutic concept in the prevention of restenosis. The liquid beta-emitter Rhenium-188 allows endovascular brachytherapy using a conventional balloon catheter without the problem of centering the radiation source. In an animal model of restenosis the feasibility and the dose dependent effect of intravascular brachytherapy with a Rhenium-188 filled balloon catheter was investigated. METHODS: In 68 male New Zealand White rabbits after endothelial denudation of the right common carotid artery with a Fogarty catheter, endovascular irradiation was performed with a Rhenium-188 filled 3.0-mm balloon catheter using different dosages (0, 7.5, 15, 30, 45 and 60 Gy at the surface of the vessel). Then 4 weeks after the intervention the vessels were excised and histologically analyzed. RESULTS: Whereas at 7.5 Gy the intimal area (median [first quartile; third quartile]) did not differ significantly from the control (0.46 mm(2) [0.33 mm(2), 0.75 mm(2)] vs. 0.49 mm(2) [0.34 mm(2), 0.66 mm(2)]), neointimal hyperplasia was decreased significantly at 15 Gy (0.15 mm(2) [0.04 mm(2), 0.17 mm(2)]) and 30 Gy (0.07 mm(2) [0.04 mm(2), 0. 10 mm(2)]), and completely inhibited at the highest dosages (45 Gy: 0 mm(2) [0 mm(2), 0.04 mm(2)]; 60 Gy: 0 mm(2) [0 mm(2), 0.01 mm(2)]). CONCLUSIONS: Catheter transmitted endovascular irradiation with the liquid beta-emitter Rhenium-188 after vascular injury is feasible and effectively reduced neointimal hyperplasia in hypercholesterolemic rabbits. A significant reduction of the neointimal formation could be found already at a radiation absorbed dose of 15 Gy at the vessel surface. Following a surface dosage of 45 Gy the proliferative response to the vessel injury is almost completely abolished.

Angioplasty, Balloon↗
PubMed2001

Anatomical distribution and sclerotic activity of bone metastases from thyroid cancer assessed with F-18 sodium fluoride positron emission tomography.

Currently, bone scintigraphy (BS) is considered to lack sensitivity in detecting bone metastases (BM) from thyroid cancer. We evaluated the anatomical distribution and metabolic behavior of BM as well as the accuracy of BS with and without combination of whole-body iodine scintigraphy (WBI) in detecting metastatic bone disease in thyroid carcinoma. F-18 positron emission tomography (PET), x-ray, BS, and WBI were performed in 35 patients with known or suspected bone metastases from papillary (9 patients) or follicular (26 patients) thyroid carcinoma. Twenty-two metastases were previously known in 14 patients. The indication was staging in 21 patients with high risk for BM, elevated thyroglobulin (Tg)-levels or evaluation of exact extent of BM (14 patients). In addition, results of WBI (35 patients), X-ray (35 patients) F-18 PET (35 patients), MRI of the spine (13 patients), and FDG-PET (15 patients) as well as the clinical course (1.5-4 years) were correlated. BM were detected in 18 patients. Solitary, bifocal, or multiple lesions were present in 9, 2, and 7 patients, respectively. The anatomical distribution of BM (n = 43) was as follows: spine, 42%; skull, 2%; thorax, 16%; femur, 9%; pelvis, 26%; humerus and clavicle, 5%. Sensitivity of BS in interpreting patients as positive or negative for having BM was 64%-85% (specificity, 95%-81%). The combination of BS and WBI was 100% sensitive in detecting metastatic bone disease. One patient had a single BM that was positive at BS but negative on WBI. All metastases were osteolytic on x-ray and two-thirds presented a missing or very limited osteosclerotic bone reaction on F-18 PET. Our data confirm the limited sensitivity of planar BS in detecting BM from thyroid cancer. The combination of BS and WBI, however, was highly accurate. Compared to other malignancies, the distribution pattern of BM presented a lower percentage of vertebral metastases and more patients with single metastases. Those findings in combination with a missing or only slight osteosclerotic bone reaction explain the limited sensitivity of planar BS alone.

Adult↗
PubMed2001

Preoperative diagnosis of ovarian tumors with MR imaging: comparison with transvaginal sonography, positron emission tomography, and histologic findings.

OBJECTIVE: Our study evaluated the diagnostic performance of MR imaging compared with that of transvaginal sonography and positron emission tomography (PET) in patients with clinically asymptomatic adnexal findings. An additional goal was to determine whether the combination of the three methods enhanced their diagnostic accuracy. SUBJECTS AND METHODS: Included in the study were 103 women with suspicious adnexal findings on sonography. Patients underwent transvaginal sonography, MR imaging, and PET within 3 weeks of the initial sonography. For MR imaging, axial and sagittal T1-weighted gradient-echo sequences (unenhanced and enhanced) and T2-weighted turbo-spin-echo sequences were acquired. Transvaginal sonography was performed with a 7.5-MHz transducer head. For PET, a modern full-ring scanner was used. The results of diagnostic imaging techniques were first evaluated separately, and reviewers were blinded to the results of other methods. Finally, a second session resulted in a consensus diagnosis based on the findings of all three methods. Results of histology were considered the gold standard. RESULTS: Histology revealed 12 malignant and 91 benign ovarian tumors. The following data were calculated for MR imaging, transvaginal sonography, PET, and consensus diagnosis: sensitivities, 83%, 92%, 58%, 92%; specificities, 84%, 59%, 78%, 84%; diagnostic accuracies, 83%, 63%, 76%, 85%, respectively. MR imaging, particularly with contrast-enhanced fat-saturated T1-weighted sequences, was found to correctly reveal dermoid and endometrial cysts. All three methods had false-negative findings with borderline tumors. CONCLUSION: Transvaginal sonography is the diagnostic method of choice as a screening technique for ovarian processes. Suspicious findings on transvaginal sonography should be confirmed on MR imaging. If MR imaging confirms a dermoid or endometrial cyst, further diagnostic procedures may be unnecessary. In all other cases, a surgical evaluation must be considered.

Adolescent↗
PubMed2001

Ki-67 immunostaining in pancreatic cancer and chronic active pancreatitis: does in vivo FDG uptake correlate with proliferative activity?

UNLABELLED: PET with 18F-FDG has been shown to be useful in the detection and staging of pancreatic cancer. However, whether FDG uptake is dependent on proliferative activity is still unclear. The aim of this prospective study was to evaluate a probable correlation between FDG uptake and proliferative activity in benign and malignant pancreatic tumors. METHODS: Our series consisted of 23 patients with pancreatic cancer and 9 patients with chronic active pancreatitis (CAP). FDG PET was performed within 2 wk before surgery, and standardized uptake values (SUVs) were calculated for benign and malignant pancreatic tumors. Patients were selected when focally increased FDG uptake in previously known pancreatic tumors was present. Proliferation fraction was measured in tissue specimens using the anti-Ki-67 antibody MIB-1. A computer-assisted imaging system was used for quantification of nuclear Ki-67 immunostaining. Immunohistochemical findings were correlated to SUVS: RESULTS: Pancreatic cancer showed both intense nuclear staining of Ki-67 (39% +/- 16%) and high FDG uptake (SUV = 3.6 +/- 1.6). However, no significant correlation was found between in vivo FDG uptake and Ki-67 immunoreactivity (P = 0.65). By contrast, Ki-67 nuclear staining was significantly lower (3.8% +/- 2.7%, P < 0.05) in CAP, whereas FDG uptake was in the same range as for pancreatic cancer (SUV = 3.5 +/- 1.8). CONCLUSION: FDG uptake did not correlate with proliferative activity in pancreatic cancer. Proliferative activity was tenfold higher in malignant pancreatic tumors than in benign tumors associated with CAP, whereas FDG uptake in vivo did not differ significantly. Thus, a PET tracer indicating cellular proliferation should better differentiate between cancer and inflammatory lesions than do metabolic markers such as FDG.

Adenocarcinoma↗
PubMed2001

Prospective evaluation of the clinical value of planar bone scans, SPECT, and (18)F-labeled NaF PET in newly diagnosed lung cancer.

UNLABELLED: Previous studies have shown that vertebral bone metastases (BM) not seen on planar bone scintigraphy (BS) might be present on (18)F-fluoride PET scans or at MRI. Therefore, we evaluated the effect of SPECT or (18)F-labeled NaF PET ((18)F PET) imaging on the management of patients with newly diagnosed lung cancer. METHODS: Fifty-three patients with small cell lung cancer or locally advanced non-small cell lung cancer were prospectively examined with planar BS, SPECT of the vertebral column, and (18)F PET. MRI and all available imaging methods, as well as the clinical course, were used as reference methods. BS with and without SPECT and (18)F PET were compared using a 5-point scale for receiver operating characteristic (ROC) curve analysis. RESULTS: Twelve patients had BM. BS produced 6 false-negatives, SPECT produced 1 false-negative, and (18)F PET produced no false-negatives. The area under the ROC curve was 0.779 for BS, 0.944 for SPECT, and 0.993 for (18)F PET. The areas under the ROC curve of (18)F PET and BS complemented by SPECT were not significantly different, and both tomographic methods were significantly more accurate than planar BS. As a result of SPECT or (18)F PET imaging, clinical management was changed in 5 patients (9%) or 6 patients (11%), respectively. CONCLUSION: As indicated by the area under the ROC curve analysis, (18)F PET is the most accurate whole-body imaging modality for screening for BM. Routinely performed SPECT imaging is practicable, is cost-effective, and improves the accuracy of BS.

Carcinoma, Non-Small-Cell Lung↗
PubMed2000

In vivo imaging of activated microglia using [11C]PK11195 and positron emission tomography in patients after ischemic stroke.

Neuroprotective strategies are currently being developed for stroke patients. Although the focus is on the development of early treatment the importance of late pathogenetic events is increasingly recognized. To investigate the microglial reaction in stroke we used a marker for activated microglia, [11C]PK11195, and PET in five patients with ischemic stroke 5-53 days after infarction. In one patient serial measurements were made. We demonstrated in each individual and at each point in time that a microglial reaction takes place in the area where T1 weighted MRI (magnetic resonance imaging) shows intensity changes. We consider this PET method as a promising tool to study the late pathogenetic consequences of cerebral infarction and to evaluate neuroprotective strategies with respect to the consequences of the microglial activation.

Adult↗
PubMed2000

Intracoronary beta-irradiation with a liquid (188)re-filled balloon: six-month results from a clinical safety and feasibility study.

BACKGROUND: Coronary irradiation is a new concept to reduce restenosis. We evaluated the feasibility and safety of intracoronary irradiation with a balloon catheter filled with (188)Re, a liquid, high-energy beta-emitter. METHODS AND RESULTS: Irradiation with 15 Gy at 0.5-mm tissue depth was performed in 28 lesions after balloon dilation (n=9) or stenting (n=19). Lesions included 19 de novo stenoses, 4 occlusions, and 5 restenoses. Irradiation time was 515+/-199 seconds in 1 to 4 fractions. There were no procedural complications. One patient died of noncardiac causes at day 23. One asymptomatic patient refused 6-month angiography. Quantitative angiography after intervention showed a reference diameter of 2. 77+/-0.35 mm and a minimal lumen diameter of 2.36+/-0.43 mm. At 6-month follow-up, minimal lumen diameter was 1.45+/-0.88 mm (late loss index 0.57). Target lesion restenosis rate (>50% in diameter) was low (12%; 3 of 26). In addition, we observed 9 stenoses at the proximal or distal end of the irradiation zone, potentially caused by the short irradiation segment and the decreasing irradiation dose at its borders ("edge" stenoses). The total restenosis rate was 46% and was significantly lower (29% vs 70%, P=0.042) when the length of the irradiated segment was more than twice the lesion length. CONCLUSIONS: Coronary irradiation with a (188)Re-filled balloon is technically feasible and safe, requiring only standard percutaneous transluminal coronary angioplasty techniques. The target lesion restenosis rate was low. The observed edge stenoses appear to be avoidable by increasing the length of the irradiated segment.

Adolescent↗
PubMed2000

Classification of asymptomatic adnexal masses by ultrasound, magnetic resonance imaging, and positron emission tomography.

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of sonography versus magnetic resonance imaging (MRI) and positron emission tomography (PET) in the characterization of adnexal masses. METHODS: One hundred and one patients with asymptomatic adnexal masses, which were scheduled for laparoscopy, underwent preoperative transvaginal ultrasound, MRI, and 2-[(18)F]fluoro-2-deoxy-d-glucose PET. Two different sonomorphological scoring systems were used to distinguish malignant from benign lesions. In addition, transvaginal Doppler flow velocimetry was performed and the resistance index (RI) of ovarian blood vessels was calculated. RI values below 0.45 were considered to indicate malignancy. MRI was evaluated on the basis of signal intensity and morphologic features such as wall thickness, septations, fluid or solid components, and vascularity. PET imaging was used to determine 2-[(18)F]fluoro-2-deoxy-D-glucose uptake. Malignancy was suspected if radiotracer uptake equaled or exceeded that of the liver. Based on histologic findings, sensitivity, specificity, positive and negative predictive values, and accuracy were first calculated independently for each imaging technique. Finally, a second session resulted in a consensus diagnosis being made based on the findings of all three modalities. RESULTS: Sonographic evaluation of adnexal masses resulted in correct classification of 11 of 12 ovarian malignancies (sensitivity 92%) but with a specificity of only 60%. With MRI and PET, specificities improved to 84 and 80% respectively, but sensitivities decreased. When all imaging modalities were combined, sensitivity and specificity were 92 and 85%, respectively, and accuracy was 86%. CONCLUSION: Combination of ultrasound with MRI and PET may improve accuracy in differentiation of benign from malignant ovarian lesions. However, negative MRI or PET results do not rule out early-stage ovarian cancer or borderline malignancies.

Adnexal Diseases↗
PubMed2000

Positron emission tomography for detection and staging of malignant lymphoma.

FDG-Positron emission tomography (FDG-PET) is an imaging modality using the physiological tracer glucose [modified as 18-fluorine-2-fluorodeoxyglucose (FDG)], whose uptake and metabolism is increased in malignant cells. While exact tumor staging in lymphomatous diseases is the basis for choosing the appropriate treatment strategy, the detection of nodal and extranodal manifestations are a key prerequisite. This study demonstrates that FDG-PET is an efficient, non-invasive method for the staging of primary untreated Hodgkin's lymphoma (HD) and non-Hodgkin's lymphoma (NHL). Clinical PET scanning is very useful in staging lymphoma patients and is more accurate than computed tomography (CT) in detecting lesions.

Female↗
PubMed2000

Experience with carbon-11 choline positron emission tomography in prostate carcinoma.

We investigated the potential of carbon-11 choline positron emission tomography (PET) for the detection of lymph node and bone metastases in prostate cancer. A total of 23 patients were studied (known metastases: 8; suspicion of metastases: 3; primary staging: 12). Whole-body PET imaging was performed 5 min after injection of the tracer and completed within 1 h. Focally increased tracer uptake in bone or abdominal lymph node regions was interpreted as representing tumour involvement. All known bone and lymph node metastases could be recognized by [11C]choline PET. One out of ten negative scans for primary staging was false-negative (lymph node <1 cm) and one out of two positive scans was false-positive with regard to lymph node involvement (focal bowel activity). It is concluded that [11C]choline PET is a promising new tool for the primary staging of prostate cancer, with lymph node and bone metastases demonstrating high tracer uptake. Therapeutic management could be influenced by these results in that the technique may permit avoidance of surgical lymph node exploration.

Aged↗