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K Scheidhauer

Publications and source records attributed to K Scheidhauer.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Quality criteria for cost-benefit analysis in oncologic nuclear medicine and state of its realization].

Additional or expensive diagnostic imaging had to prove prospectively their diagnostic efficacy, their therapeutic efficacy, or their patient-outcome efficacy. The adherence to methodologic standards in the cost-effectiveness literature is required. Based on the bone scintigraphy in oncologic patients with a low prevalence of bone metastases, the cost-effectiveness is questionable. The economic role of 99m-Tc MIBI mammoscintigraphy and of the imaging for carcinomas of unknown origin is discussed controversially. Based on the reimbursement of the positron emission tomography (PET) in the USA and in Switzerland, cost-effectiveness literature and decision trees for cost-utility analyses are reviewed. PET imaging was cost-effective in non-small-cell lung cancer, in solitary pulmonary nodules, in recurrent colorectal cancer, in metastatic melanoma and in recurrent head and neck cancer with reduced costs of management. The German health insurance calls for PET-data based on the national reimbursement.

Breast Neoplasms↗
PubMed1998

Somatostatin receptor imaging in intracranial tumours.

The somatostatin analogue [111In-DTPA-d-Phe1]-octreotide (111In-octreotide) allows scintigraphic visualization of somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express somatostatin receptors and 111In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of 111In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63 meningiomas, 24 pituitary adenomas, 10 gliomas WHO class I and II, 12 gliomas WHO class III and IV, 11 neurinomas and 2 neurofibromas, 7 metastases and 12 other varieties: three non-Hodgkin B-cell lymphomas, two epidermoids, one abscess, one angioleiomyoma, one chordoma, one haemangiopericytoma, one osteosarcoma, one plasmacytoma and one pseudocyst), 111In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq 111In-octreotide. Planar images of the head in four views with a 128x128 matrix and single-photon emission tomographic images (64x64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63 meningiomas showed moderate to intense tracer uptake. Nine of 24 pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV gliomas showed 111In-octreotide uptake. None of the neurinomas or neurofibromas were positive. Five of seven metastases were classified as positive, as were the osteosarcoma, two of three non-Hodgkin B-cell lymphomas, one abscess, one angioleiomyoma, one chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin B-cell lymphoma, two epidermoids, one plasmacytoma and one pseudocyst) did not show 111In-octreotide uptake. The results demonstrate that a large variety of intracranial lesions express somatostatin receptors and therefore can be visualized by [111In-DTPA-d-Phe1]-octreotide scintigraphy. This technique can be valuable in the differentiation between meningiomas and pituitary adenomas, based on qualitative tracer uptake. [111In-DTPA-d-Phe1]-octreotide scintigraphy allows differentiation between meningiomas and neurinomas or neurofibromas and therefore provides complementary information to computed tomography or magnetic resonance imaging. Furthermore, this technique allows differentiation between scar tissue and recurrent meningiomas postoperatively and can help in non-invasive tumour differentiation of multiple intracranial lesions, which can be of value in defining the most adequate therapeutic strategy.

Adolescent↗
PubMed1998

Decreased trabecular bone mineral density in patients with phenylketonuria measured by peripheral quantitative computed tomography.

The bone mineral density (BMD) of 14 children, adolescents, and adults with phenylketonuria (PKU) on dietary treatment (age 5-28 y; 6F, 8M) was investigated using peripheral quantitative computed tomography (pQCT) of the distal radius. BMD of total (TBMD) and spongy bone (SBMD) were compared to those of healthy gender-, age-, weight- and height-matched controls. We found a significant decrease of SBMD in patients with PKU while TBMD was only slightly decreased, reaching no statistical significance. These results indicate minor changes of BMD in patients with PKU under treatment, which are more accentuated in the trabecular bone compartment. One additional patient who was untreated until the pQCT investigation at the age of 10 y also showed markedly decreased SBMD and TBMD.

Adolescent↗
PubMed1998

Follow-up of differentiated thyroid cancer: what is the value of FDG and sestamibi in the diagnostic algorithm?

AIM: FDG-PET and MIBI-scintigraphy with SPECT were compared to [131I]-whole-body scintigraphy (WBS) and morphologic imaging in the follow-up of differentiated thyroid cancer. Their influence of therapy-planning was analysed. METHODS: In 50 consecutive patients (papillary/ follicular/variants of a follicular carcinoma: 33/13/4; primary status: pT1/2/3/4: 3/16/9/22) FDG-PET of neck/chest and MIBI-whole-body scan including SPECT were performed during hypothyreosis and before WBS. Morphologic imaging was done by MRI in all and by CT of the lung without contrast media in 21 patients. RESULTS: The complete extent of metastases was detected by FDG-PET in 11 and by MIBI-scintigraphy also in 11 of 22 patients with evidence of disease. The combined evaluation of WBS and FDG-PET as well as of WBS and MIBI-scintigraphy held true in 18 of 22 patients. Limiting FDG-PET or MIBI-scintigraphy to patients with elevated thyroglobulin (Tg)-levels and negative WBS only, would not, therefore, alter the sensitivity of this algorithm. The diagnostic benefit of FDG-PET and MIBI-scintigraphy was confined to lymph node metastases. The 1 cm limit for lymph node size in morphologically based imaging did not apply to FDG-PET and MIBI-scintigraphy. None of the 6 patients with small (< 1 cm) pulmonary metastases showed either FDG- or MIBI-uptake, but could be diagnosed by spiral-CT. CONCLUSION: WBS cannot be replaced by FDG-PET or MIBI-scintigraphy; neither of the latter was better than the other. Rising Tg-levels, negative WBS and the exclusion of pulmonary metastases by spiral-CT define the constellation in which FDG-PET and MIBI-scintigraphy can provide data of therapeutic relevance.

Adult↗
PubMed1998

Estrogen receptor scintigraphy.

Radio-labeled estrogen receptor ligands are tracers that can be used for functional receptor diagnosis. Their specificity towards receptors, together with the fact that only 50-70% of mammary carcinomas are receptor positive, renders them unsuitable for detection of primary tumors or metastases, and this means that estrogen receptor scintigraphy can be used neither for tumor screening nor for staging. However, both 18F-labeled and 123I-labeled estradiol derivatives are suitable for in vivo imaging of estrogen receptors. Their high specificity, established in animal experiments and in vitro studies has been reproduced in in vivo applications in humans. Tracers with positron radiation emitters are, however, hardly suitable for broad application owing to the short half-life of 18F, which would mean that users would need to be situated close to a cyclotron and a correspondingly equipped radiochemical laboratory. The number of available PET scanners, on the other hand, has increased over the last few years, especially in Germany, so that this, at least, does not present a limiting factor. All the same, 123I-labeled estradiol derivatives will find more widespread application, since the number of gamma-cameras incorporating modern multi-head systems is several times greater. The results of studies with 123I-E2-scintigraphy published to date are very promising, even given the initial technical problems mentioned above. As a method of examination, it could be optimised by using improved tracers with a higher tumor contrast and less disturbance from overlapping in diagnostically relevant locations, for instance, by selecting tracers with higher activities whose excretion is more renal than hepatobiliary. The use of modern multi-head camera systems can also be expected to improve the photon yield.

Animals↗
PubMed1998

[Kinetics of receptor-mediated radiotoxicity of 16alpha-[125I]-iodostradiol-3,17beta].

AIM: The radiocytotoxic effects in estrogen receptor (ER) containing MCF-7 cells of a mamma carcinoma were investigated following incubation with [125I]E ranging from 1 h to 24 h. METHODS: The receptor status of the cells was confirmed by immunohistochemical staining. The accumulation of [125I]E in MCF-7 cells was tested in the presence and absence of radioinert E and [127I]E and in ER-negative cells in comparison to ER-positive cells. The subcellular distribution was investigated in 0.25 M Saccharose by ultra centrifugation. The radiocytotoxicity was assessed in ER-positive and negative cells by a standard colony forming assay after incubating with [125I]E (1.85 kBq/ml-55.5 kBq/ml) for 1, 2, 4, 8, 12, and 24 h. RESULTS: A significant cytotoxicity was observed only when ER-rich MCF-7-cells were incubated with [125I]E alone. The maximal cytotoxic effect was a reduction of survival fraction to 20-25%. This was achieved at radioactivity concentrations > 37 kBq/ml. Maximal effect was seen after 8 h incubation, extension of incubation time did not further increase toxicity. CONCLUSION: The results suggest that the radioactivity was bound to ER. Through their nuclear localization radioestrogens tagged with radionuclides emitting very low energy electrons (Auger electrons) bear potential for therapy by ER-mediated deposition of lethal doses of ionizing radiation to single cells without affecting neighbouring cells. But, instead of 125I the shorter-living 123I shall be used for labelling because the deciding radiation effectes occur within the first 8 h.

Biological Transport↗
PubMed1997

[99mTc-MDP-SPECT for detection of subclinical mandibular infiltration of squamous epithelial carcinoma].

UNLABELLED: A prospective study was performed to compare the sensitivity and accuracy of ultrasound (US), computed tomography (CT), and single photon emission computed tomography (SPECT) as a bone scan to detect subclinical invasion of the mandible by squamous cell carcinoma of the oral cavity and floor of mouth. METHODS: The present study reports data on 35 patients with squamous cell carcinoma of the oral cavity. SPECT, mandibular orthopantomography (OPG), US, CT and magnetic resonance imaging (MRI) were performed as well as histologic examination of resected mandibles. Transverse slices of 12 mm thickness were reconstructed for SPECT and semi-quantitative assessment of radionuclide uptake was performed with a scoring system based on comparisons of tracer uptake in the mandible to that in an unaffected part of the mandible. Lesion to non-lesion count ratios in the mandible in 3 h SPECT images were calculated. OPG, US and CT were evaluated for comparison. RESULTS: In 12/35 patients, histologic examination showed carcinoma infiltrating mandibular bone. SPECT correctly predicted mandibular invasion in 11/12 cases, with no false-positive results. CT detected correctly 3/12 lesions, while OPG and ultrasound each demonstrated 2/12 tumors. CONCLUSION: Bone SPECT was found to provide an accurate means for assessing tumor invasion to the mandible by intraoral squamous cell carcinoma. As a complementary study to one of the other imaging modalities it was shown to have a high specificity, indicating that it should be performed routinely in patients with suspect mandibular bone involvement by causes.

Adult↗
PubMed1997

Fluorine-18 fluorodeoxyglucose positron emission tomography and iodine-131 whole-body scintigraphy in the follow-up of differentiated thyroid cancer.

Metastases of differentiated thyroid cancer may show different uptake patterns for fluorine-18 fluorodeoxyglucose and [131I]NaI. FDG positron emission tomography (PET), iodine-131 whole-body scintigraphy (131I WBS) and magnetic resonance imaging were performed in 58 unselected patients, and spiral computed tomography (CT) of the lung in 25 patients. Thirty-eight patients presented with papillary carcinomas, 15 patients with follicular carcinomas and five patients with variants of follicular carcinoma. Primary tumour stage (pT) was pT1 in 3, pT2 in 19, pT3 in 11 and pT4 in 25 cases. For the detection of metastases, FDG PET was found to have a sensitivity of 50%, 131I WBS a sensitivity of 61%, and the two methods combined a sensitivity of 86%. When FDG PET was limited to patients with elevated thyroglobulin (Tg) levels and negative 131I WBS, the sensitivity of this algorithm was 82%. Of the 21 patients with lymph node metastases, seven presented with FDG uptake but no iodine uptake. In four of them, a second FDG hot spot appeared in a lymph node metastasis of normal size. Five of the seven patients underwent surgery. None of the eight patients with pulmonary metastases smaller than 1 cm exhibited FDG uptake, while five of them had iodine uptake. All had positive results on spiral CT. In conclusion, FDG PET cannot be substituted for 131I WBS. If the Tg level is elevated and 131I WBS is negative, FDG PET can be used to detect lymph node metastases and complements anatomical imaging. A spiral CT of the lung is useful to exclude pulmonary metastases before planning a dissection of iodine-negative lymph node metastases.

Adult↗
PubMed1997

Nuclear medical assessment of penile hemodynamics following revascularization surgery.

Variations of Hauri's penile revascularization have been in clinical use since 1983. The hemodynamics of the so-called three-vessel anastomosis remain uncertain despite successful, clinically reproducible results. The goal of this study was to depict the increased perfusion of the erectile system of the penis following revascularization by means of the inferior epigastric artery. Ten milliliters of heparinized peripheral venous blood was drawn from 10 patients prior to surgery. The radioactively tagged erythrocytes (1 mCi 99mTc) were reinjected via an additional incision in the donor vessel proximal to the anastomosis following completion of the three-vessel anastomosis and intracavernous injection of 20 micrograms PGE1. Once again, blood was drawn during the tumescence phase from both a peripheral vein and the corpora cavernosa within the normal circulatory duration and compared to the original specimen. Eight of ten patients displayed evidence of primary reperfusion of the corpora cavernosa via the inferior epigastric artery as the donor vessel. Using strict indications, revascularization of the penis is an effective mode of therapy for arterial erectile dysfunction.

Anastomosis, Surgical↗
PubMed1997

[Influence on extratumoral organ activities of tumor-affinity samarium-153 preparations].

AIM: Possibilities to exercise an influence on the biodistribution of a tumor-affine 153Sm-preparation, samarium-153-nitrilotriacetate (NTA), were tested. METHODS: Animals experiments on tumor-bearing mice after additional application of EDTMP (ethylenediamine tetramethylene phosphonate) for the reduction of extratumorale liver-radioactivity and yttrium chloride for the reduction of unwanted underground radioactivity in bone were carried out. Furthermore, the combination of both measurements was tested. RESULTS: The biodistribution of 153Sm-NTA showed a rather low tumor-radioactivity of app. 0.72%/g. The additional EDTMP-application caused a dose-dependent decrease of the underground-radioactivity in liver especially if given 2 h in advance or simultaneously. The additional application of the stable yttrium salt reduced the bone radioactivity on simultaneous increase of liver- and spleen-radioactivity and practically unchanged tumor-radioactivity. The combined use of EDTMP together with the bone-affine metal salt led to a reduction of liver radioactivity on simultaneous reduction of bone radioactivity. CONCLUSIONS: The background radioactivity can be reduced on unchanged tumor-radioactivity by combined Na-EDTMP/YCl3-application. The present results do not allow a therapeutic exploitation because of the low tumor accumulation.

Animals↗
PubMed1996

Clinical relevance of somatostatin receptor scintigraphy in patients with skull base tumours.

The differential diagnosis of tumours in the skull base is often difficult. With the experience that various intracranial tumours differ in their expression of somatostatin binding sites (SBS) somatostatin receptor scintigraphy (SRS) with the somatostatin analogue octreotide can give additional information of the tumour entity. Seventy patients with various tumours of the skull base were examined with 111Indium-labelled DTPA-octreotide injected i.v.. Planar and tomographic images were obtained with a gamma camera 4-6 and 24 hours after injection. All of the meningiomas (unifocal and multifocal tumours in various locations) showed a high density of SBS whereas in none of the examined neurinomas SR were found. Pituitary adenomas revealed in only 50% SR in different concentrations and independent of the endocrine activity. SRS can help in the differential diagnosis between meningiomas and other tumours, postoperative scar or radionecrosis at the skull base. A dural infiltration with meningioma tissue ("meningeal sign") may be discriminated from a reactive hypervascularisation in lesions with a diameter > 0.5 cm. We conclude that SRS can offer additional diagnostic aspects in the pre- and postoperative management of patients with skull base tumours.

Adenoma↗
PubMed1996

Qualitative [18F]FDG positron emission tomography in primary breast cancer: clinical relevance and practicability.

Positron emission tomography (PET) using fluorine-18 2-deoxy-2-fluoro-d-glucose (FDG) is of potential value for the diagnosis of malignant tumours. The aim of this study was to evaluate the use of FDG PET in patients with breast tumours, appraising its applicability in visualising primary carcinomas and regional metastases in a clinical setting. Results of FDG PET were compared with those of mammography, breast ultrasonography and histology in 30 patients with inconclusive breast findings. For PET, transmission and emission images were taken in one or two scan positions, depending on the available time and the clinical status of patients. PET showed focal FDG uptake with high contrast in 21 of 23 primary carcinomas. In one patient, only PET correctly visualized multifocal disease (three foci, O 0.4-1 cm). The accuracy of PET in the detection of primary breast cancer was 90%, and in the detection of involved axillary lymph nodes, 94%. All metastases (lymph nodes, lungs, bones, soft tissues) covered by the field of view and demonstrated by other methods (X-ray, computed tomography, magnetic resonance imaging, bone scan) showed FDG uptake. In three patients, only PET initiated further diagnostic procedures. The results indicate that FDG PET can provide a rapid diagnostic study (45-60 min) and allows accurate tumour staging of several organ systems for primary tumour and metastases with a single imaging study in a routine clinical setting.

Breast Neoplasms↗
PubMed1996

[Detection of multi-focal breast carcinoma using 2[18F] fluoro-deoxy-D-glucose positron emission tomography (FDG-PET)].

The elevated rate of glycolysis in malignomas compared to normal tissues can be visualised by positron-emission-tomography (PET) using 2[18F]fluoro-deoxy-D-Glucose (FDG). Based on the case of a 38-year old woman with multifocal carcinoma of the right breast (pT1 c pN0 M0, G2) as a vehicle, we describe a FDG-PET procedure which is comparable to established methods of nuclear medicine (e.g. bone scan) with regard to patient's burden and time consumption and could be used on a routine basis. This technique allowed correct assessment of suspicious breast findings and visualised multifocal growth of a tumour which was judged to be a unifocal breast cancer by conventional methods of clinical examination, mammography and ultrasound.

Adult↗
PubMed1996

Influence of muscle strength on bone strength during childhood and adolescence.

In connection with the prevention of osteoporosis, paediatrics is challenged with ensuring the optimal formation of the skeletal system with maximal bone strength during childhood and youth. Biomechanical use represents the most important stimulus for activating the skeletal system. The measurement of muscle strength (grip strength) in 97 females aged 3-62 years and 71 males aged 3-61 years showed an age-dependent course. On the whole, males have greater strength with a more pronounced increase after puberty, reaching a peak maximum at 25-30 years. Females show a more moderate increase after puberty. In a pilot study, bone strength (as bone strength index-BSI) was analysed at the distal radius using peripheral quantitative computerized tomography (pQCT). BSI was calculated on the basis of the geometric data of the polar moment of resistance in combination with the cortical bone density. BSI values increase with age and reach a peak maximum at 25-30 years. There was a highly significant correlation between BSI and grip strength (r = 0.87). These relationships are especially interesting for therapeutic concepts differentiating between direct and indirect (via the muscle system) influences on the skeletal system. The non-invasive bone strength analysis in combination with muscle strength offer new perspectives for the evaluation of the functional muscle-bone unit.

Adolescent↗
PubMed1996

[Relationship between properties of 131I therapy and radioiodine kinetics].

AIM: The reason of unreproducible data under diagnosis and therapy with radioiodine should be elucidated. METHODS: The iodine content of the capsules was tested by a colorimetric method and by activation analysis. Radiochemical purity was determined by HPLC and by electrophoresis. Solubility of the capsules was investigated under different conditions. RESULTS: The iodine content of the capsules varied between 0.8 and appr. 100 micrograms/capsule. The radiochemical purity of the capsule iodine varied between 75% and 99.5% (main contamination: iodate). The solubility of the capsules differed. CONCLUSION: Additional non-radioactive iodine in the therapy capsules could be one reason of the reduced radioiodine-uptake under therapy.

Capsules↗
PubMed1995

The role of nuclear medicine in diagnosis of catheter-related infections.

Infections represent a complication after transient or permanent implantation of medical devices (e.g. catheters or pacemaker systems), leading in many cases to therapeutic consequences such as the removal of the implanted system. Diagnosis of foreign body infections is difficult and mainly based on clinical findings rather than laboratory methods or modern morphological imaging tools. Two-dimensional echocardiography by transthoracic and transesophageal approach may be helpful in the detection of vegetations, but is not very sensitive for infections. Most methods in nuclear medicine, however, are based on function and not on form: some methods for the detection of an infection are unspecific like the use of labelled nanocolloids or Ga-67-citrate, or they need time-consuming and susceptible techniques for the labelling of autologous leukocytes. Monoclonal antibodies against epitopes on granulocytes, however, offer a fast and reliable in-vivo labelling technique. It has been demonstrated in a group of four patients that scintigraphic detection of pacemaker infections by immunoscintigraphy may represent a valuable diagnostic tool.

Animals↗
PubMed1995

[Biokinetics of tumor-affinity yttrium preparations--2].

After demonstrating that the application form 87Y-NTA-EDTMP-Ca is superior to the so far used citrate form of yttrium especially regarding the tumour/liver and tumour/bone ratios, the relationships between the concentrations of the components in the 87Y-NTA-EDTMP-Ca mixture and the 87Y biokinetics were investigated in tumour-bearing mice. The increase of the EDTMP and Ca2+ concentrations by several orders of magnitude caused no significant changes of tumour radioactivity but a clear radioactivity decrease in the liver, spleen and bone, respectively. The increase of the NTA concentration led also to a radioactivity decrease in all organs and tissues investigated. A significant radioactivity reduction in the tumour could be observed only after administration of rather high NTA amounts. Considerations of the tumour/background ratios depending on different compositions of the injection mixture showed the possibility of optimizing radionuclide biodistribution.

Animals↗