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C Franzius

Publications and source records attributed to C Franzius.

At least 19 recordsLinked to original sources
PubMed2006

Tumor staging using whole-body high-resolution 16-channel PET-CT: does additional low-dose chest CT in inspiration improve the detection of solitary pulmonary nodules?

For optimal image fusion between CT and F-18-FDG-PET, the acquisition of CT images is performed in mild expiratory suspension, which might compromise the detection of lung metastases. This study aimed at evaluating the influence of expiration on the detection of solitary pulmonary nodules (SPN) and at assessing if additional inspiratory low-dose CT (I-LDCT) of the chest can improve the detection of potential lung metastases performing whole-body 16-channel PET-CT. Sixty-six patients with malignant tumors underwent PET-CT: contrast-enhanced CT was acquired during mild expiration and was used for fusion with PET images; additionally, chest I-LDCT was performed at deep inspiration. Two radiologists reported all SPN detected at I-LDCT and the expiratory CT scan independently. Overall, 53% of 128 SPN (mean: 3.8+/-0.2 mm) were detected at both respiratory states: 51 SPN only at I-LDCT, and 9 nodules only at expiratory CT. Of the SPN, 117/128 were classified as certain; 45 of those were additionally detected at I-LDCT, and 6 nodules at expiratory CT. A 100% detection rate was reached in SPN >4 mm at I-LDCT versus >8 mm at expiratory CT (all P<0.001). Additional I-LDCT of the chest significantly improves the detection of SPN at whole-body F-18-FDG-PET-CT and thus is recommended as part of the standard protocol for oncological patients.

Adult↗
PubMed2006

Mucinous cystadenocarcinoma--an extremely rare tumor in a young patient.

We report on an extremely rare case of pulmonary mucinous cystadenocarcinoma. A 29-year-old male patient was admitted because of progressive enlargement of a right lower lobe mass over a period of 10 years. Right lower lobectomy was performed after a malignant mucinous cystadenocarcinoma was diagnosed by intraoperative frozen section. PET and CT scans did not detect metastatic disease. This case is the youngest patient reported so far with a malignant pulmonary mucinous cystadenocarcinoma and highlights the importance of close follow-up of indeterminate pulmonary nodules in patients with unremarkable history.

Adult↗
PubMed2006

High diagnostic value of 18F-FDG-PET in pediatric patients with chronic inflammatory bowel disease.

Diagnosis of chronic inflammatory bowel disease (IBD) in children requires noninvasive, atraumatic diagnostic tools that depict localization and acuity of inflammation and yield only a low radiation dose. This retrospective analysis evaluates the diagnostic potential of FDG-PET. Twenty-six consecutive FDG-PET scans of 23 patients (age: 2-16, years, 14 M, 9 F) with suspected IBD were analyzed in this retrospective study. Results were compared to endoscopic, histologic, and abdominal ultrasound (US) finding. In these examinations, presence of inflammation was evaluated in each patient in 8 bowel segments (score 1-4). Standardized uptake values (SUVs) for FDG-PET were measured for all segments. Sensitivity, specificity, and accuracy were calculated using histology as the standard of reference on a segment-based analysis (pathologic if inflammation score > or = 3 or SUV(max)/SUV(liver)>1.2). With histology as the standard of reference, FDG-PET showed a sensitivity/specificity/accuracy of 98%/68%/8%/3 as compared to endoscopy (90%/75%/82%) and US (56%/92%/75%). For the small bowel, FDG-PET was even more reliable (100%/86%/90%). Because of its high sensitivity and accuracy,FDG-PET is an excellent, noninvasive diagnostic tool for IBD. Depicting inflammation in the whole bowel, while being not traumatic, it is attractive for use especially in children. FDG-PET is especially reliable for the small bowel and can inform application of topical therapy.

Adolescent↗
PubMed2005

Staging in childhood lymphoma: differences between FDG-PET and CT.

AIM: The clinical value of positron emission tomography using fluorine-18 fluoro-deoxy-glucose (FDG-PET) in the staging of adult lymphoma has been shown in many studies. However, there are only few data regarding childhood lymphoma. The purpose of this retrospective study was to compare the staging of childhood lymphoma using FDG-PET and the established computed tomography (CT). METHOD: Whole-body FDG-PET was performed in 25 children with histologically proven Hodgkin's disease (n = 18) and non-Hodgkin's lymphoma (n = 7) using a dedicated PET. The findings were compared with the CT results. Both examinations, FDG-PET and CT, were assessed by two experienced physicians. In each patient, 30 regions were analysed (22 nodal, 8 extranodal). Each region was assessed using a five value scale (definitely/probably positive, equivocal, probably/definitely negative). RESULTS: 662 regions (470 nodal, 192 extranodal) were compared. 91 regions (81 nodal, 10 extranodal; 14%) were concordant positive and 517 regions (347 nodal, 170 extranodal; 78%) were concordant negative. In 47 regions, 48 discordant findings (7%) were described: 27 findings (22 nodal, 5 extranodal) were positive using FDG-PET and negative using CT whereas 21 findings (17 nodal, 4 extranodal) were positive using CT and negative using PET. A total of 7 regions (1%) were judged equivocal in one imaging modality (1 FDG-PET, 6 CT). Using FDG-PET as compared to CT, resulted in a higher staging in 4 of 25 patients and in a lower staging in 2 of 25 patients. CONCLUSION: Staging of childhood lymphoma using FDGPET shows differences compared with CT resulting in a different staging in 6 of 25 patients. Prospective studies are required to evaluate the impact of these discrepancies on the clinical management of pediatric patients.

Adolescent↗
PubMed2003

Assessment of therapy response by FDG PET in pediatric patients.

Little is known about the clinical value of FDG PET for assessing treatment response in pediatric oncology. After systematic review of literature, the very few publications concerning response control in pediatric oncology using FDG PET are summarized. There were only 4 studies concerning FDG PET in the assessment of therapy response in pediatric patients. None of the publications fulfilled the requirements for high quality studies because of the small number of patients studied. The clinical value of FDG PET in the assessment of therapy response in pediatric oncology is likely in osseous sarcomas and possibly in high-grade brain tumors. In other pediatric tumor entities such as lymphomas, soft-tissue sarcomas, germ cell tumors, or neuroblastomas, the clinical usefulness of FDG PET can either be assumed analogous to adults, or can be assumed from staging studies, or is still unknown. There is a need for large, systematic studies evaluating FDG PET in therapy monitoring, but also in grading, staging, and in the diagnosis of recurrences in pediatric malignancies.

Adolescent↗
PubMed2003

Iodine excretion during stimulation with rhTSH in differentiated thyroid carcinoma.

AIM: Elevated iodine intake is a serious problem in the diagnostic and therapeutic application of (131)iodine in patients with differentiated thyroid cancer. Therefore, iodine avoidance is necessary 3 months in advance. Additionally, endogenous stimulation requires withdrawal of thyroid hormone substitution for 4 weeks. Exogenous stimulation using recombinant human TSH (rhTSH) enables the continuous substitution of levothyroxine, which contains 65.4% of its molecular weight in iodine. Thus, a substantial source of iodine intake is maintained during exogenous stimulation. Although this amount of stable iodine is comparable to the iodine intake in regions of normal iodine supply, it may reduce the accumulation of radioiodine in thyroid carcinoma tissue. The aim of this study was to assess the iodine excretion depending on different ways of stimulation. METHODS: Iodine excretion was measured in 146 patients in the long term follow up after differentiated thyroid carcinoma. Patients were separated into 2 groups, those on hormone withdrawal (G I) and rhTSH-stimulated patients on hormone substitution (G II). RESULTS: Iodine excretion was significantly lower in hypothyroid patients (G I, median 50 micro g/l, range: 25-600 micro g/l) than in those under levothyroxine medication (G II, median 75 micro g/l, 25-600 micro g/l, p <0.027). TSH in G I (median 57.0 micro U/ml, range: 14.4-183 micro U/ml) was significantly lower (p <0.001) than in G II (117 micro U/ml, 32.2-281 micro U/ml). CONCLUSION: Iodine excretion was higher in patients under rhTSH-stimulation than after hormone withdrawal. This may indicate an increased iodine pool in rhTSH-stimulated patients (deiodination of levothyroxine), thus limiting the sensitivity of radioiodine scanning to the level of endogenous stimulation despite significantly higher TSH levels during rhTSH-stimulation.

Adenocarcinoma, Follicular↗
PubMed2002

[Valence of F-18-FDG-PET in the diagnosis of malignant lymphoma].

PET enables tomographic imaging and quantification of molecular metabolism with high temporal and spatial resolution. For routine clinical questions in oncology F-18-labeled fluorodeoxyglucose is the tracer of choice. In malignant lymphoma staging, response control and follow-up studies are valid indications. The initial glucose-uptake and especially the response of metabolism to therapy are in correlation with the outcome of the disease. Complementary to conventional staging PET is able to detect further lymphnode manifestation or extranodal involvement that can result in up-staging. Down-staging is less frequent. In follow-up studies PET is valuable, to assess therapy response, to differentiate viability of lymphoma from fibrous remnants at end of therapy and to detect relapse at an early stadium. In this context it proves to be superior to conventional tomographic imaging. In individual cases relevant therapeutic consequences arise from the metabolic PET-informations. Whether in future PET will be able to partially replace conventional imaging and whether it withstands to cost/effectiveness analysis requires additional prospective studies.

Blood Glucose↗
PubMed2002

FDG-PET for detection of recurrences from malignant primary bone tumors: comparison with conventional imaging.

BACKGROUND: The aim of this study was to assess the diagnostic ability of positron emission tomography using 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG-PET) in the detection of recurrences from malignant primary bone tumors compared with conventional imaging. PATIENTS AND METHODS: In 27 patients (6 osteosarcomas, 21 Ewing's sarcomas), 41 FDG-PET examinations performed for diagnosis or exclusion of recurrent disease were evaluated. Conventional imaging techniques consisted of magnetic resonance imaging of the primary tumor site, thoracic computed tomography, and Tc-99m methylene diphosphonate bone scintigraphy. The reference methods were the histopathological analysis and/or the clinical and imaging follow-up. RESULTS: In 25 examinations reference methods revealed 52 sites of recurrent disease (local n = 7; distant: osseous n = 22, pulmonary n = 13, soft tissue n = 10). On an examination-based analysis FDG-PET had a sensitivity of 0.96, a specificity of 0.81 and an accuracy of 0.90. Corresponding values for conventional imaging were 1.0, 0.56 and 0.82. CONCLUSIONS: The sensitivity, specificity and accuracy of FDG-PET in the detection of recurrences from osseous sarcomas are high. On an examination-based analysis, FDG-PET had a not significantly lower sensitivity in comparison with conventional imaging. However, FDG-PET showed a small advantage in the detection of osseous and soft-tissue recurrences compared with conventional imaging.

Adolescent↗
PubMed2002

Follow-up of perfusion defects in pulmonary perfusion scanning after pulmonary embolism: are we too careless?

Persisting perfusion defects may still be found in pulmonary perfusion scintigraphy months or years after pulmonary embolism. The aim of this study was to investigate the rate of persisting perfusion defects and the pattern of scintigraphic follow-up of patients after pulmonary embolism. Only those patients were included into our study who received pulmonary perfusion scintigraphy between 1991 and 1999, and who had perfusion defects including at least one whole segment. These perfusion defects were considered as persisting perfusion defects if unchanged over at least 1 year. From 3640 patients examined, 451 (12.4%) had perfusion defects meeting the criteria of this study. Of those, 129 (28.6%) received a scintigraphic follow-up. In 62 patients (48.1%), a reperfusion of the defects was found. In 38 patients (29.5%), the defects persisted within a follow-up period of up to 12 weeks. However, no pulmonary perfusion scintigraphy was performed thereafter. Out of the 129 patients receiving a scintigraphic follow-up, only 29 (22.5%) had a follow-up over more than 1 year, 19 of those had persisting perfusion defects. It is concluded that our data show an inadequate scintigraphic follow-up of patients with pulmonary embolism which may lead to unnecessary anticoagulant treatment if persisting perfusion defects are misinterpreted as fresh pulmonary embolism. In many cases, there was no further follow-up even if reperfusion of the defects was lacking in early follow-up.

Adult↗
PubMed2001

[Role of FDG-PET in oncological surgery].

Fluorine-18 fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) allows in vivo analysis of tissue metabolic activity. Based on the observation that most malignant tumors display a higher metabolic activity than benign tissues, [18F]FDG-PET offers an interesting option for the diagnosis of primary and recurrent malignant tumors. For the oncological surgeon [18F]FDG-PET is particularly helpful for the diagnosis of tumors of the pancreas, colorectum, lung and esophagus. This short review describes the biological basis of [18F]FDG-PET and gives a critical discussion of its role in oncological surgery.

Blood Glucose↗
PubMed2001

[Clinical value of positron emission tomography (PET) in the diagnosis of bone and soft tissue tumors. 3rd Interdisciplinary Consensus Conference "PET in Oncology": results of the Bone and Soft Tissue Study Group].

PURPOSE: In the framework of the 3rd Consensus Conference "PET in Oncology" the bone and soft-tissue tumors study group evaluated the present position of PET for these tumor entities on the basis of international publications. METHODS: After a systematic review of the literature, publications were evaluated according to previously defined quality criteria. For various indications the clinical usefulness of PET was assessed using a classification system. RESULTS: Most studies had been performed with a small number of patients (n < 35). Therefore, only 8 of 46 publications were judged relevant. On the basis of these literature data, use of FDG-PET for grading was classified 1b (literature results predominantly show clinical usefulness). As before (1995/97), all other indications were categorized with 3 (assessment not yet possible, literature data inadequate). OUTLOOK: According to the opinion of experts, the detection of osseous metastases of Ewing's sarcoma, therapy monitoring and the diagnosis of recurrences are potentially useful clinical indications for FDG-PET. Therefore, prospective studies with large patient groups are essential to further evaluate the benefit of FDG-PET in these indications.

Age Factors↗
PubMed2001

Characterization of 3-[123I]iodo-L-alpha-methyl tyrosine ([123I]IMT) transport into human Ewing's sarcoma cells in vitro.

3-[(123)I]Iodo-L-alpha-methyl tyrosine ([(123)I]IMT) scintigraphy of extracranial malignant tumors has been described, but little is known about the transport systems involved in [(123)I]IMT uptake into extracranial tumor cells. Here, the precise kinetics of [(123)I]IMT transport into human Ewing's sarcoma cells (VH-64) was determined. The apparent Michaelis constant was of high affinity value (K(m)=41.7+/-3.9 microM) and maximum transport velocitiy amounted to V(max)=20.7+/-0.6 nmol x mg protein(-1) x 10 min(-1). Inhibition experiments revealed the predominance of [(123)I]IMT uptake via sodium-independent system L.

Biological Transport↗
PubMed2001

Kinetic parameters of 3-[(123)I]iodo-L-alpha-methyl tyrosine ([(123)I]IMT) transport in human GOS3 glioma cells.

The radiolabelled amino acid 3-[(123)I]iodo-L-alpha-methyl tyrosine ([(123)I]IMT) is a promising tool for the diagnosis and monitoring of brain tumors using single-photon emission tomography (SPECT). However, little is known about the precise kinetics of [(123)I]IMT uptake in human glioma cells. The kinetic analysis of [(123)I]IMT transport in human GOS3 glioma cells yielded a high-affinity apparent Michaelis constant (K(m) = 20.1 +/- 1.5 microM). The maximum transport velocity (V(max)) amounted to 34.8 +/- 1.9 nmol/mg protein/10 min. Competitive inhibition experiments revealed that [(123)I]IMT transport is mediated principally by the sodium-independent system L.

Biological Transport↗
PubMed2001

FDG-PET for detection of pulmonary metastases from malignant primary bone tumors: comparison with spiral CT.

BACKGROUND: The purpose was the comparison of positron emission tomography using F-18-fluorodeoxy-glucose (FDG-PET) and spiral thoracic CT to detect pulmonary metastases from malignant primary osseous tumors. PATIENTS AND METHODS: In 71 patients with histologically confirmed malignant primary bone tumors (32 osteosarcomas, 39 Ewing's sarcomas) 111 FDG-PET examinations were evaluated with regard to pulmonary/pleural metastases in comparison with spiral thoracic CT. Reference methods were the clinical follow-ups for 6-64 months (median 20 months) or a histopathologic analysis. RESULTS: In 16 patients (23%) reference methods revealed a pulmonary/pleural metastatic disease. FDG-PET had a sensitivity of 0.50, a specificity of 0.98, and an accuracy of 0.87 on a patient based analysis. Comparable values for spiral CT were 0.75, 1.00, and 0.94. It was shown that no patient who had a true positive FDG-PET had a false negative CT scan, nor was a pulmonary metastases detected earlier by FDG-PET than by spiral CT. CONCLUSIONS: There seems to be a superiority of spiral CT in the detection of pulmonary metastases from malignant primary bone tumors as compared with FDG-PET. Therefore, at present a negative FDG-PET cannot be recommended to exclude lung metastases. However, as specificity of FDG-PET is high, a positive FDG-PET result can be used to confirm abnormalities seen on thoracic CT scans as metastatic.

Adolescent↗
PubMed2001

Whole-body MR imaging for detection of bone metastases in children and young adults: comparison with skeletal scintigraphy and FDG PET.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of whole-body MR imaging, skeletal scintigraphy, and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for the detection of bone metastases in children. SUBJECTS AND METHODS: Thirty-nine children and young adults who were 2--19 years old and who had Ewing's sarcoma, osteosarcoma, lymphoma, rhabdomyosarcoma, melanoma, and Langerhans' cell histiocytosis underwent whole-body spin-echo MR imaging, skeletal scintigraphy, and FDG PET for the initial staging of bone marrow metastases. The number and location of bone and bone marrow lesions diagnosed with each imaging modality were correlated with biopsy and clinical follow-up as the standard of reference. RESULTS: Twenty-one patients exhibited 51 bone metastases. Sensitivities for the detection of bone metastases were 90% for FDG PET, 82% for whole-body MR imaging, and 71% for skeletal scintigraphy; these data were significantly different (p < 0.05). False-negative lesions were different for the three imaging modalities, mainly depending on lesion location. Most false-positive lesions were diagnosed using FDG PET. CONCLUSION: Whole-body MR imaging has a higher sensitivity than skeletal scintigraphy for the detection of bone marrow metastases but a lower sensitivity than FDG PET.

Adolescent↗