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H Bender

Publications and source records attributed to H Bender.

At least 19 recordsLinked to original sources
PubMed2006

Effects of surface relaxation on convergent-beam electron diffraction analysis of stress in silicon.

Convergent-beam electron diffraction on cross-sectional transmission electron microscopy specimens can map strains in the silicon substrate of microelectronics devices with high spatial resolution. However, at shallow depths below the interface, most of the diffraction lines within a convergent-beam electron diffraction pattern are split, rendering pattern interpretation impossible in the classic way. The splitting effect was systematically analysed for a variety of materials, and the same qualitative behaviour that can be explained by stress relaxation at the surfaces of the thin transmission electron microscopy specimen was observed. The effects of surface relaxation are modelled by finite elements simulations. The results predict well the experimental magnitude of the splitting for a variety of diffraction lines at different positions below the interface, but fail to simulate the intensity of the secondary lines. Possible reasons for such discrepancies are discussed and assessed.

Journal Article↗
PubMed2005

FDG-PET in immunocompetent patients with primary central nervous system lymphoma: correlation with MRI and clinical follow-up.

PURPOSE: The role of FDG-PET in primary central nervous system lymphoma (PCNSL) is unclear. It was the aim of this study to investigate the role of FDG-PET in detecting PCNSL and in predicting response to chemotherapy. METHODS: An FDG-PET scan of the brain was performed in 15 patients with histologically proven PCNSL (16 PET examinations, Siemens ECAT EXACT). PET was planned to investigate patients at the time of primary diagnosis, after chemotherapy and at the time of suspected relapse in seven, five and three cases, respectively. All except two patients simultaneously underwent MRI of the brain. FDG-PET results were correlated with histological results after stereotactic biopsy (primary diagnosis group) and with clinical data and MRI during follow-up. RESULTS: Six of the seven patients in the primary diagnosis group demonstrated a true positive finding (86%). In one of the true positive PET patients, there were two tumour lesions, one of which was only detectable on the FLAIR MRI sequence. In five patients, FDG-PET showed no sign of PCNSL during ongoing chemotherapy. These results were confirmed by the clinical follow-up (mean 26.6 months). MRI demonstrated minimal residual disease which had disappeared on further follow-up MRI in three of these five patients at the time of PET scanning. Recurrence of disease was confirmed concordantly by FDG-PET and MRI in three different patients. The standardised uptake value of all tumours was 10.2 (4.3-13.7). CONCLUSION: PCNSLs demonstrate high FDG uptake and can be diagnosed by FDG-PET with high sensitivity. It seems that FDG-PET is suitable for early therapeutic monitoring after chemotherapy.

Aged↗
PubMed2005

[Therapy with radioisotopes in oncology. Palliative and curative approaches].

For more than 50 years now, nuclear medicine has offered therapeutic procedures in oncology. These comprise bone pain palliation in bone metastases of prostate and breast cancer. For more than 20 years now, metaiodobenzylguanidine (mIBG) has been used to treat neuroendocrine tumors. Ten years ago, somatostatin analogues such as Y-90 Dotatoc became available for the treatment of somatostatin receptor-positive tumors. The intracavitary injection of radiocolloids has been well known for 5 decades now and can be used in malignant effusions. Invasive procedures such as intra-arterial injection of I-131 lipiodol may be applied in multifocal, nonresectable hepatocellular carcinoma. Beyond that, intratumoral injection of radioisotopes may be used in cutaneous metastases. Radioimmunotherapy using labeled tumor antibodies is now also available, especially in patients with non-Hodgkin's lymphoma.

Humans↗
PubMed2004

FDG-PET in monitoring therapy of breast cancer.

Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been used successfully for the staging and re-staging of breast cancer. Another significant indication is the evaluation of therapy response. Only limited data are available on the use of FDG-PET in breast cancer after radiation therapy. The same holds true for chemotherapy. Only the therapy response in locally advanced breast cancer after chemotherapy has been investigated thoroughly. Histopathological response could be predicted with an accuracy of 88-91% after the first and second courses of therapy. A quantitative evaluation is, of course, a prerequisite when FDG-PET is used for therapy monitoring. Only a small number of studies have focussed on hormone therapy. In this context, a flare phenomenon with increasing standardised uptake values after initiation of tamoxifen therapy has been observed. More prospective multicentre trials will be needed to make FDG-PET a powerful tool in monitoring chemotherapy in breast cancer.

Antineoplastic Agents↗
PubMed2002

Comparison of [18F]FDG-PET and L-3[123I]-iodo-alpha-methyl tyrosine (I-123 IMT)-SPECT in primary lung cancer.

OBJECTIVE: The aim of this study was to evaluate L-3[123I]-iodo-alpha-methyl tyrosine (IMT)-SPECT and FDG-PET in pulmonary lesions suspected to be lung cancer. METHODS: Whole body PET (measured transmission corrected emission scans) was performed 45 minutes after i.v. injection of 222-370 MBq (6-10 mCi) 18F-FDG on a Siemens PET scanner (ECAT EXACT 47) including 5-6 bed positions. 123I-IMT-SPECT (chest) was performed after injection of 370 MBq (10 mCi) with a dual head camera (Picker Prism 2000) and commercially available reconstruction algorithms. Ten patients (6 male and 4 female) with suspected lung cancer were investigated. The results were compared to histological findings after surgery or bronchoscopic biopsies and CT. RESULTS: 123I-IMT-SPECT and FDG-PET were able to detect all 9 cases of lung cancer (1-8 cm in diameter). One case was true negative. Both imaging methods were true positive with respect to mediastinal lymph node metastases in one patient. The tumor/background ratio was higher with PET (8.20 vs. 2.84). CONCLUSION: Despite the limited number of patients it may be concluded that IMT-SPECT as well as FDG-PET are suited to correctly diagnose lung cancer. Nevertheless, FDG-PET, if available, seems to be better suited because of the higher tumor/background ratio and better resolution.

Carcinoma, Non-Small-Cell Lung↗
PubMed2002

Value of tumour marker S-100B in melanoma patients: a comparison to 18F-FDG PET and clinical data.

AIM: The S-100B protein is commonly used in the immunohistochemical diagnosis of malignant melanoma and its metastases and has recently been introduced as a tumor marker in peripheral blood, whereas 18F-FDG PET is currently the most sensitive in-vivo imaging method for melanoma staging. Thus, the efficiency of serum S-100B and 18F-FDG PET in the detection of metastatic disease in melanoma patients are compared. METHODS: Serum S-100B was measured with a commercially available immunoradiometric assay. As part of primary tumour staging whole-body positron emission tomography (PET) with 18F labeled fluorodeoxy-D-glucose (18F-FDG) was performed in 67 patients suffering from cutaneous melanoma with a tumour thickness > 0.75 mm and a Clark-level III-V. Final diagnosis based on histology, morphologic imaging results and/or clinical follow-up after at least six months. RESULTS: No evidence of disease was seen in 43 of 67 patients (64.2%), 11 patients (16.4%) presented with lymph node metastases, 13 patients (19.4%) had one or more distant metastases. Alltogether, 18 of 67 patients showed S-100B values > 0.2 microgram/l, including two patients without metastatic disease, 3 of 11 patients with lymph node metastases, and the 13 patients with distant metastases. One patient showed false-positive FDG-uptake in the mediastinum, but presented with S-100B values off curve. CONCLUSION: Our data indicate that serum S-100B determination might be helpful in identifying melanoma patients with distant metastases. In comparison to 18F-FDG PET, the value of serum S-100B for lymph-node staging is limited.

Adult↗
PubMed2000

[Diagnostic value of pentavalent 99mTc-dimercaptosuccinicacid ([V]-DMSA) in head and neck tumors].

The purpose of this investigation was to assess the biodistribution of 99mTc-[V]-DMSA in human being, and its diagnostic value in patients with head and neck tumours. 20 patients with histologically confirmed head and neck tumours were examined with planar as well as SPECT scintigraphy. Whole body scintigraphy in different time after injection of 99mTc-[V]-DMSA was performed to assess the major sequential organ biodistribution. Our results showed that the blood clearance of 99mTc-[V]-DMSA was bi-exponential. All organs except kidneys showed a relatively rapid elimination of 99mTc-[V]-DMSA. The kidneys showed a increasing accumulation in the first 2 h, which is probably due to the tubular reabsorption of 99mTc-[V]-DMSA. In 15 of 20 patients, 19 lesions could be proven by means of planar scintigraphy (corresponding sensitivity of 75%). 29 lesions in 18 patients could however be detected by the application of SPECT (corresponding sensitivity of 90%). Except primary tumours and local lymphadenmetastases in 5 patients distant metastases (3 thorax wall, 1 liver and 1 inguinal/paravesicle) were found. Altogether a sensitivity of 76.9% and a specificity of 71.4% were calculated for the detection of primary tumour. The sensitivity and specificity for the exploration of lymphadenmetastases were 75% and 100%. In conclusion, this study show that 99m Tc-[V]-DMSA, particularly with SPECT imaging, is useful in localising the primary tumours and lymphadenmetastases as well as distant metastases of head and neck tumours. The possible therapeutic application of 188/186Re-[V]-DMSA is also evaluated.

Adult↗
PubMed2000

Dose escalation study with rhenium-188 hydroxyethylidene diphosphonate in prostate cancer patients with osseous metastases.

The aim of this study was to determine the maximum tolerated dose of rhenium-188 hydroxyethylidene diphosphonate (HEDP) in prostate cancer patients with osseous metastases who are suffering from bone pain. Twenty-two patients received a single injection of escalating doses of carrier-added 188Re-HEDP [1.3 GBq (35 mCi), 2.6 GBq (70 mCi), 3.3 GBq (90 mCi) and 4.4 GBq (120 mCi)]. Blood counts and biochemical parameters were measured weekly over a period of 8 weeks. Haematological toxicity (WHO grading) of grade 3 or 4 was considered unacceptable. Clinical follow-up studies including methods of pain documentation (medication, pain diary) were performed for 6 months after treatment. In the 1.3-GBq group, no haematological toxicity was observed. First haematotoxic results were noted in those patients with a dose of 2.6 GBq 188Re-HEDP. In the 3.3-GBq group, one patient showed a reversible thrombopenia of grade 1, one a reversible thrombopenia of grade 2 and three a reversible leukopenia of grade 1. In the 4.4-GBq group, thrombopenia of grades 3 and 4 was observed in one and two patients (baseline thrombocyte count <200x10(9)/l), respectively, and leukopenia of grade 3 was documented in one patient. The overall nadir of thrombopenia was at week 4. The individual, maximum percentage decrease in thrombocytes in the 1.3-, 2.6-, 3.3- and 4.4-GBq groups was 17%, 40%, 60% and 86%, respectively. In two patients, a transient increase in serum creatinine was observed (max. 1.6 mg/dl). Pain palliation was reported by 64% of patients, with a mean duration of 7.5 weeks. The response rate seemed to increase with higher doses, reaching 75% in the 4.4-GBq group. It is concluded that in prostate cancer patients, the maximum tolerated dose of 188Re-HEDP is 3.3 GBq if the baseline thrombocyte count is below 200x10(9)/l. In patients with thrombocyte counts significantly above 200x10(9)/l, a dose of 4.4 GBq might be tolerable. Thrombo- and leukopenia are the most important side-effects. Pain palliation can be achieved in 60%-75% of patients receiving a dose of 2.6 GBq or more of 188Re-HEDP. Studies in a larger patient population are warranted to evaluate further the palliative effect of 188Re-HEDP.

Bone Neoplasms↗
PubMed2000

Detection of somatostatin receptor-positive tumours using the new 99mTc-tricine-HYNIC-D-Phe1-Tyr3-octreotide: first results in patients and comparison with 111In-DTPA-D-Phe1-octreotide.

Indium- 111 labelled DTPA-D-Phe1-octreotide (DTPA-OC, OctreoScan) has been introduced into clinical routine for the detection of somatostatin receptor (SSTR)-positive tumours, which are predominantly of neuroendocrine origin. Potential further applications in other SSTR-positive cancers (e.g. small cell lung cancer, breast cancer, melanoma) have been limited mainly by the restricted availability and the high radionuclide costs. Previous attempts to introduce technetium-99m labelled analogues of octreotide have not been very successful in terms of the labelling procedure, in vivo biodistribution and/or tumour detection capabilities. The aim of this study was to assess the performance of the new 99mTc-labelled analogue HYNIC-D-Phe1-Tyr3-octreotide (HYNIC-TOC), using tricine as co-ligand, for the detection of SSTR-positive tumours in patients in comparison with 111In-DTPA-OC. Overall, 13 patients were examined using 99mTc-tricine-HYNIC-TOC. Twelve patients had proven SSTR-positive tumours, while one patient presented with an SSTR-negative tumour. In 9 of the 13 patients both tracers (99mTc-tricine-HYNIC-TOC and 111In-DTPA-OC) were used. Serial whole-body scans, spot views and/or single-photon emission tomography studies were performed. Images were qualitatively and semi-quantitatively (ROI analyses) evaluated. The biodistribution of 99mTc-tricine-HYNIC-TOC in patients showed high physiological uptake in kidneys, moderate uptake in liver and spleen and little uptake in the gut. The tracer showed predominantly renal and negligible hepatobiliary excretion. Known SSTR-positive tumour sites showed rapid and intense tracer accumulation. 99mTc-tricine-HYNIC-TOC demonstrated rapid tissue uptake within the first hour after injection and had basically no significant clearance (<20%) from normal or tumour tissue thereafter. In contrast, 111In-DTPA-OC showed continuous clearance from normal tissues as well as renal and very little hepatobiliary excretion. Nevertheless, the patterns of accumulation of 99mTc-tricine-HYNIC-TOC in tumours and normal organs were comparable to those of 111In-DTPA-OC. A lesion-by-lesion comparison showed comparable tumour detection capabilities in intrahepatic tumour sites and superior capabilities of 99mTc-tricine-HYNIC-TOC in respect of extrahepatic lesions. In conclusion, 99mTc-tricine-HYNIC-TOC shows promise as a tracer for SSTR imaging, given its favourable clinical characteristics (specific and high receptor affinity, good biodistribution, renal excretion, low radiation exposure, high imaging quality, on-demand availability) and cost-effectiveness. 99mTc-tricine-HYNIC-TOC allows earlier diagnosis (10 min-4 h) compared with 111In-DTPA-OC (4-24 h).

Adult↗
PubMed2000

Membranes for endotoxin removal from dialysate: considerations on feasibility of commercial ceramic membranes.

As the quality of water in dialysis fluid varies considerably, dialysate is often contaminated by large amounts of bacteria and endotoxins. Membrane properties and operating pressures are acknowledged to give high-flux dialysis with bicarbonate the bacteriological potential to favor passage of endotoxin fragments from the dialysate into the blood stream. Therefore, a sterile dialysate will have to become a standard. Ultrafiltration across hydrophobic synthetic membranes was shown to remove endotoxins (and their fragments) from dialysis water by the combined effect of filtration and adsorption. However, each module can be used for a limited time only. Ceramic membranes may represent an alternative to polymeric membranes for endotoxin removal. In this article, we tested the capacity of different commercial ceramic membranes with nominal molecular weight cut-off down to 1,000 to retain endotoxins from Ps. aeruginosa. The tested membranes did not generally produce dialysate meeting the Association for the Advancement of Medical Instrumentation standard. When using aluminum-containing membranes, we detected aluminum leaking into the dialysate that could possibly be transported into the blood stream.

Ceramics↗
PubMed2000

Intraarterial HCC therapy with I-131-Lipiodol.

We report on our 2-year experience with intraarterial liver therapy with I-131-Lipiodol in patients with hepatocellular carcinoma in Germany. 30 therapies with intraarterial delivery of I-131-labeled Lipiodol were performed in 14 patients with hepatocellular carcinoma (HCC) with or without portal vein thrombosis during hepatic angiography. The patients were monitored for 1) distribution of Lipiodol by CT, 2) distribution of applied activity by planar scintigraphy and SPECT, and 3) tumor response by CT, MRT and 18-FDG-PET. In 5 patients the tumor size was reduced after the first treatment (responder). Eight patients, primarily with big tumors (> 7 cm), had stable (4) or progressive disease (4), and 1 patient died because of renal failure. CT and SPECT showed pronounced I-131-lipiodol accumulation in the tumor tissue in all patients with variable distribution patterns. One patient had an acute pancreatitis like syndrome together with elevation of liver enzymes, probably due to arterial spasm. 9 patients had transient and mild symptoms in the upper abdomen, fever to 40 degrees C, and a leukocytosis. Two patients had a transient mild elevation of pancreatic enzymes. All patients had a transient rise in liver enzymes. In conclusion, therapeutic efficacy was dependent on the tumor mass. Side effects due to the radiopharmaceutical were tolerable, and other side effects may result from the angiography procedure related manipulations. These results are encouraging for tumors up to a moderate mass.

Aged↗
PubMed2000

FDG PET and immunoscintigraphy with 99mTc-labeled antibody fragments for detection of the recurrence of colorectal carcinoma.

UNLABELLED: The aim of this study was to compare FDG PET with a new monoclonal antibody-based imaging agent that comprises an anti-carcinoembryonic antigen (CEA) monoclonal antibody Fab' fragment directly labeled with 99mTc. METHODS: Twenty-eight patients who were previously treated for colorectal carcinoma and in whom recurrence was suspected were examined with FDG PET and immunoscintigraphy. The most common indications were an elevation of serum CEA (13 patients), suggestive lesions documented by CT (9 patients), sonography (4 patients), and severe constipation (2 patients). Planar imaging and SPECT were performed 4-6 h after intravenous injection of the new imaging agent. Whole-body PET was performed 45-60 min after intravenous injection of FDG. The findings were confirmed by conventional diagnostic modalities, surgery, and histology. RESULTS: Histology confirmed local tumor recurrence in 9 of 28 patients. Clinical follow-up or CT confirmed the presence of liver metastases in 9 patients and lymph node involvement, lung metastases, and bone metastases in 2 patients each. The new agent correctly detected 8 of 9 local recurrences, whereas FDG PET was able to detect all 9 cases and in 1 case was false-positive. Liver metastases were confirmed in 9 patients by FDG PET but in only 1 patient by the new agent. Two cases with lymph node metastases and 2 cases with lung metastases were correctly identified by FDG PET, but none were detected by the new agent. Finally, bone metastases were identified in 1 patient by FDG PET but not with the new agent, whereas bone marrow infiltration (n = 1) was diagnosed by both imaging modalities. CONCLUSION: These results indicate that FDG PET and 99mTc-labeled anti-CEA Fab' are suitable for the diagnosis of local recurrence of colorectal carcinoma but that FDG PET is clearly superior in the detection of distant metastases (liver, bone, and lung) and lymph node involvement.

Antibodies, Monoclonal↗
PubMed1999

Positron emission tomography in the clinical staging of patients with Stage I and II testicular germ cell tumors.

OBJECTIVES: To evaluate the accuracy of fluorodeoxyglucose positron emission tomography (PET) compared with computed tomography (CT) staging in patients with Stage I and II testicular germ cell tumors (GCTs). METHODS: From January 1995 to July 1997, in 37 patients with clinical Stage (CS) I (n = 25) and CS II (n = 12) GCT (24 nonseminomas, 13 seminomas), PET and CT were compared in the initial staging. After PET, the patients with nonseminomatous GCT were staged surgically by retroperitoneal lymph node dissection and the patients with seminomatous GCT were followed up clinically. RESULTS: Correct staging by PET was achieved in 34 of 37 patients compared with correct CT staging in 29 of 37 patients. Of 10 metastatic lesions, 7 and 4 were detected by PET and CT, respectively. PET did not show false-positive signals. PET was unable to detect vital cancer with a maximal diameter less than 0.5 cm or teratoma at any size. CONCLUSIONS: PET was useful for detecting viable tumor in lesions that are visible on CT scan and, thus, it may omit false-positive CS II lesions. However, PET was not able to identify mature teratoma. In this study, PET did not improve the staging in patients with CS I tumor.

Germinoma↗
PubMed1999

I-131-Lipiodol therapy in liver neoplasms.

Twelve patients with liver neoplasms [10 HCC, 1 CCC, 1 multiple breast cancer metastases (BCM)] were treated by transarterial I-131-Lipiodol. Computed tomography (CT) and single photon emission CT (SPECT) showed pronounced I-131-Lipiodol accumulation in the tumor tissue in all cases. In three patients with HCC a reduction of tumor size was achieved after the first treatment. The remaining patients had big tumor masses; 5 of these (4 HCC, 1 CCC) had stable disease after the first treatment, and 2 HCC were progressive. One patient died immediately after therapy due to other reasons. The BCM proved significant reduction in number and size. Eighteen-FDG-PET (positron emission tomography with fluor-18-deoxy-glucose) and CT controls showed in part different results with pretherapeutic PET proving high interindividual variability in tumor activity. Side effects were tolerable. In summary, the therapy procedure with transarterial I-131-Lipiodol is safe and effective in tumors with moderate tumor mass.

Aged↗