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W Eschner

Publications and source records attributed to W Eschner.

At least 19 recordsLinked to original sources
PubMed2006

Is there a benefit of 131 I-MIBG therapy in the treatment of children with stage 4 neuroblastoma? A retrospective evaluation of The German Neuroblastoma Trial NB97 and implications for The German Neuroblastoma Trial NB2004.

AIM: (131)I-meta-iodobenzylguanidine ((131)I-MIBG) therapy has been used in neuroblastoma treatment for many years but its value in high intensive first line treatment protocols is not exactly known. PATIENTS, METHODS: Stage 4 neuroblastoma patients >1 year with (123)I-MIBG positive residual disease (primary tumour and/or metastasis) after complete induction chemotherapy according to the German neuroblastoma trial NB97 were retrospectively analyzed. RESULTS: One-hundred-eleven patients had (123)I-MIBG positive residual disease after complete induction chemotherapy. Forty patients received (131)I-MIBG therapy using a median activity of 0.44 GBq/kg body weight. By univariate analysis, patients who underwent (131)I-MIBG therapy had a better 3-year event free survival (3-y-EFS 46 +/- 8%) and 3-year overall survival (3-y-OS 58 +/- 9%) than 71 patients without (131)I-MIBG therapy (3-y-EFS 19 +/- 5%, p = 0.003; 3-y-OS 43 +/- 6%, p = 0.037). However, subgroup analysis of 66 patients who underwent high dose chemotherapy with autologous stem cell transplantation (ASCT) during treatment found a very similar outcome with (131)I-MIBG therapy (3-y-EFS 49 +/- 9%, 3-y-OS 59 +/- 10%) and without (131)I-MIBG therapy (3-y-EFS 33 +/- 9%, p = 0.171; 3-y-OS 59 +/- 9%, p = 0.285) due to the dominating effect of ASCT. By multivariate analysis, (131)I-MIBG therapy had no impact on EFS (p = 0.494) and OS (p = 0.891). Only ASCT, external beam radiation therapy and MYCN amplification were important for EFS and OS. CONCLUSIONS: An independent advantage of I-131-MIBG therapy could not be proven in this retrospective analysis. The ongoing German Neuroblastoma Trial NB2004 will address the influence of (131)I-MIBG therapy with emphasis on tumour dosimetry.

3-Iodobenzylguanidine↗
PubMed2006

[Dosimetry for therapeutic treatment of neuroblastoma by 131I-mIBG].

AIM: Targeted radiotherapies using iodine-131 meta-iodobenzylguanidin have long been in use for treatment of stage IV neuroblastoma but reliable dosimetric data are scarce. METHOD: This work presents an approach to determine the whole body exposure and tumour doses delivered during therapy. Dosimetric data are reported and discussed for six treatments carried out according to the trial protocol NB2004 as it is in use in our study in the last two years. RESULTS: Whole body exposures are found to be in the range of 1.75 to 2.5 Gy whereas tumour doses vary between 15 and 55 Gy. CONCLUSION: The course of action prescribed by the trial protocol allows whole body exposure as well as tumour doses to be determined routinely.

3-Iodobenzylguanidine↗
PubMed2005

[Established nuclear medicine techniques for tumour diagnosis (tumour SPECT): can they still compete with (18)F-FDG-PET?].

This overview presents the indications of tumour SPECT in contrast to tumour PET using (18)F-FDG. A number of diagnostic SPECT radiopharmaceuticals have been used for years in oncology and are widely available in nuclear medicine departments. Today, tumour SPECT has to compete with tumour PET using (18)F-FDG. Other PET radiopharmaceuticals are common only in specialised centers. In comparison to SPECT, PET images with their higher resolution are technically superior. Therefore, PET is better than SPECT in localising a tumour, if the special tumour entity accumulates (18)F-FDG. Thus, (18)F-FDG-PET has largely replaced SPECT examinations using (201)Tl chloride, (67)Ga citrate or (99m)Tc anti-CEA. It is questionable whether mammascintigraphy using (99m)Tc-MIBI or (99m)Tctetrofosmine will be broadly accepted in clinical routine. SPECT radiopharmaceuticals are still up to date for examination of tumour entities which do not accumulate (18)F-FDG (e. g. neuroendocrine tumours) and in clinical problem solving if (18)F-FDG-PET is not regarded as superior (e. g. search for recurrent medullary thyroid carcinoma) or in the management of tumours with overlapping diagnosis and therapy as it is the case for differentiated thyroid carcinomas ((123)I/(131)I-NaI), phaeochromozytomas, and neuroblastomas ((123)I/(131)I-MIBG), carcinoids, gastroenteropancreatic tumours, paragangliomas, and Merkel-cell tumours (somatostatin receptor scintigraphy). Future developments concerning new SPECT radiopharmaceuticals and image fusion such as SPECT/CT are expected.

Fluorodeoxyglucose F18↗
PubMed2005

[Radioimmunotherapy with yttrium-90 ibritumomab tiuxetan. Clinical considerations, radiopharmacy, radiation protection, perspectives].

90Y-ibritumomab tiuxetan (Zevalin) is currently approved for radioimmunotherapy of patients with relapsed or refractory follicular non-Hodgkin's lymphoma pretreated with rituximab. Future directions are the combined use of 90Y-ibritumomab tiuxetan as part of the initial treatment and as first-line multi-agent therapy of relapsed disease. Current studies investigate patients with other than follicular indolent histologies, e. g. diffuse large cell lymphoma. Labelling of 90Y ibritumomab tiuxetan is a safe procedure, the radiochemical purity is not disturbed by a higher room temperature or by metallic impurity. Quality control is recommended by thin layer chromatography (TLC), strips >15 cm are favourable. TLC cannot distinguish between the correctly radiolabelled antibodies and radiocolloid impurity. If necessary, additional HPLC should be performed. Radiocolloid impurities are absorbed to the solid phase and do not reach the eluate. If the radiochemical purity test is insufficient (<95%), the additional cleaning using EconoPac 10 DG columns (Biorad, Hercules, CA, USA) is a reliable procedure to reduce the percentage of free radionuclide. However, this procedure is not part of the approval.

Anemia↗
PubMed2004

18F-FDG PET for detecting recurrent head and neck cancer, local lymph node involvement and distant metastases. Comparison of qualitative visual and semiquantitative analysis.

AIM: Assessment of the clinical value of (18)F-FDG-PET for detection of recurrent head and neck cancer, local lymph node involvement and distant metastases comparing a qualitative visual with a semiquantitative analysis (SUV values). PATIENTS, METHODS: Retrospective evaluation of 73 (18)F-FDG PET studies in 55 patients by use of a four-step qualitative visual grading system and calculation of standard uptake values in pathological lesions. Calculation of SUV values in normal regions for generating a map of physiological (18)F-FDG distribution. Correlation to histopathological findings and clinical follow-up. RESULTS: 1. Qualitative visual analysis of (18)F-FDG PET studies: a) local recurrence sensitivity 79%, specificity 97%, positive predictive value 95%, negative predictive value 85%, and diagnostic accuracy 89%; b) local metastatic lymph nodes 100%, 95%, 85%, 100%, 96%; c) distant metastases 100%, 98%, 86%, 100%, 98%, respectively. 2. Semiquantitative analysis had only little incremental, non-significant value in comparison to qualitative visual analysis for the detection of a local recurrence in two patients: a) local recurrence: sensitivity 83%, specificity 100%, positive predictive value 100%, negative predictive value 88%, and diagnostic accuracy 93%; b) local metastatic lymph nodes or c) distant metastases did not change in comparison to qualitative visual analysis. CONCLUSION: (18)F-FDG PET is an effective tool for re-staging of patients with suspected recurrence after therapy for head and neck cancer.

Carcinoma, Squamous Cell↗
PubMed2003

[Hodgkin's lymphoma in nuclear medicine: diagnostic and therapeutic aspects].

Today, diagnostic and therapeutic strategies of Hodgkin lymphoma (HL) with positron emission tomography and radioimmunotherapy include state-of-the-art nuclear medicine which require the cooperation between oncology and nuclear medicine. The benefit of FDG-PET in HL patients with residual tumor masses consists of its high negative predictive value in the therapy control of the disease. The concept of waitful watching in patients with PET-negative residual masses after BEACOPP-chemotherapy will be evaluated in a large multicenter trial of the GHSG (German Hodgkin Study Group). Radioimmunotherapy has been performed in patients with CD20-positive Non-Hodgkin lymphoma for 10 years with promising results. HL is also an excellent target for immunotherapy due to the expression of antigens such as CD25 and CD30. Thus, a new radioimmunoconstruct consisting of the murine anti-CD30 antibody Ki-4 labeled with iodine-131 was developed for patients with relapsed or refractory HL.

Fluorodeoxyglucose F18↗
PubMed2003

[Procedure guideline for radioiodine test (version 2)].

The version 2 of the procedure guideline for radioiodine test is an update of the guideline published in 1999. The following statements were added or modified: The procedure guideline discusses the pros and cons of a single measurement or of repeated measurements of the iodine-131 uptake and their optimal timing. Different formulas are described when one, two or three values of the radioiodine kinetic are available. The probe with a sodium iodide crystal, alternative or additionally the gamma-camera using the ROI-technique are instrumentations for the measurement of iodine-131 uptake. A possible source of error is an inappropriate measurement (sonography) of the target volume. The patients' preparation includes the withdrawal of antithyroid drugs 2-3 days before radioiodine administration. The patient has to avoid iodine-containing medication and the possibility of additives of iodide in vitamin- or electrolyte-supplementation has to be considered.

Documentation↗
PubMed2003

[Procedure guideline for thyroid scintigraphy (version 2)].

The version 2 of the procedure guideline for thyroid scintigraphy is an update of the procedure guideline published in 1999. The procedure guideline considers the current amendment of legislative rules (Richtlinie Strahlenschutz in der Medizin 2002). Indication and use of radiopharmaceuticals have to be confirmed by the specialist in nuclear medicine. Activities of 75 MBq technetium-99m, respectively of 10 MBq iodine-123 should not be exceeded without an individual justification. The interpretation of the scintigraphy requires the knowledge of the patients' history, the palpation of the neck, the laboratory parameters, and of the sonography. The interpretation of the technetium-99m uptake requires the knowledge of TSH concentration.

Humans↗
PubMed2003

[Procedure guideline for iodine-131 whole-body scintigraphy for differentiated thyroid cancer (version 2)].

The version 2 of the procedure guideline for iodine-131 whole-body scintigraphy for differentiated thyroid cancer is an update of the procedure guideline published in 1999. The following statements are added or modified: The two alternatives of an endogenous TSH-stimulation by the withdrawal of the thyroidal hormone medication and of an exogenous TSH-stimulation by the injection of the recombinant human TSH (rhTSH) have an equal sensitivity for the diagnostic use of radioiodine and for the measurement of thyroglobulin. Image acquisition under rhTSH is obtained approximately 48 h after the radioiodine administration, while an interval of about 72 h is preferred under endogenous TSH-stimulation. If iodine-negative metastases are expected, the feasibility of scintigraphy using (99m)Tc sestamibi or preferably positron emission tomography using (18)F-fluorodeoxyglucose should be considered. The sensitivity of FDG-PET is increased by TSH-stimulation. Before planning the iodine-131 scintigraphy the patient has to avoid iodine-containing medication and the possibility of additives of iodine in vitamin- and electrolyte-supplementation has to be considered.

Diagnosis, Differential↗
PubMed2001

[Exhalation of I-131 after radioiodine therapy (RIT): time dependence and chemical form].

AIM: The change of both amount and chemical forms of radioiodine exhaled in the air of rooms with patients on the therapy ward should be investigated depending on radioactivity applied, time after application, and kind of thyroid disease. METHODS: The air of ward-rooms of 62 patients with thyroid carcinoma, Graves' Disease, and autonomy which received different therapy doses, was investigated with an portable constant air flow sampler. Different chemical iodine species (organic, elemental, aerosol bound) were collected during 8 hr in various filters until 3 days after application of the radioiodine capsule, according to their chemical form. The radioactivity in the filters was measured with a well counter on defined time points after application. RESULTS: The radioactivity exhaled was between 0.008 and 0.03% related to activity of radioiodine applied. The percentage of radioiodine exhaled related to the activity applied, differed significantly depending on disease and changed as follows: Grave's Disease > autonomy > carcinoma. The exhalation of radioiodine became stronger with increasing applied activities and showed an exponential decrease with time. The most part of radioiodine was present in organic bound form. This organic portion decreased with time in favour of the other iodine species. CONCLUSION: The degree of accumulation of radioiodine orally applied within thyroid seems to be in direct proportion to the extend of its exhalation. Further measurements directly in the breathing air of RIT-patients are necessary, in order to clarify the relationship between degree of thyroid uptake and quantity as well as chemical form of radioiodine exhaled.

Air Pollutants, Radioactive↗
PubMed2000

Iterative reconstruction: an improvement of technetium-99m MIBI SPET for the detection of parathyroid adenomas?

The purpose of this study was to assess the value of technetium-99m methoxyisobutylisonitrile (MIBI) single-photon emission tomography (SPET) and an iterative reconstruction algorithm for the preoperative localisation of parathyroid adenomas (PTAs). Seventy-two patients (26 male, 46 female, mean age 58+/-16 years) with known primary hyperparathyroidism were examined preoperatively. First, a thyroid examination was performed to detect possible MIBI-accumulating thyroid lesions. Planar scans were then acquired 15 and 120 min and tomographic images 120 min after intravenous injection of 740 MBq 99mTc-MIBI, using a triple-head gamma camera (Picker Prism 3000). Additionally, 99mTc-MIBI/ 99mTc-pertechnetate subtraction scintigraphy of the early planar images was performed. The SPET data were evaluated using an iterative reconstruction (multiplicative iterative SPET reconstruction: MISR) as well as a standard algorithm (FBP: filtered back-projection with application of a 3-D low-pass postfilter). The weight of the resected PTAs ranged from 110 mg to 5 g. Using planar MIBI scans, correct localisation of the side of the PTA was possible in 81% of cases (58% for PTAs weighing less than 500 mg). Sensitivity increased to 94% using SPET and FBP, while with MISR it rose further, to 97%. Patients with PTAs weighing less than 500 mg showed a sensitivity of 88% with MISR and 81% with FBP. Furthermore, there was a clear improvement in image quality using MISR. None of the normal parathyroid glands were visualised. This study indicates that, in comparison with planar scintigraphy, 99mTc-MIBI SPET is a more sensitive and specific tool for topographical localisation of PTAs, especially those that are small. There is a further improvement in sensitivity and image quality when iterative reconstruction is used instead of FBP.

Adenoma↗
PubMed2000

Assessment of intracellular water by whole body bioelectrical impedance and total body potassium in HIV-positive patients.

OBJECTIVE: Bioelectrical impedance analysis (BIA) is widely used as bedside assessment of body composition. Body cell mass (BCM) and intracellular water (ICW) are clinically important body compartments. Estimates of ICW obtained from BIA by different calculation approaches were compared to a reference method in male HIV-infected patients. PATIENTS: Representative subsample of clinically stable HIV-infected outpatients, consisting of 42 men with a body mass index of 22.4 +/- 3.8 kg/m(2)(range, 13-l31 kg/m(2)). METHODS: Total body potassium was assessed in a whole body counter, and compared to 50 kHz monofrequency BIA and multifrequency bioelectrical impedance spectroscopy. Six different prediction equations for ICW from BIA data were applied. Methods were compared by the Bland-Altman method. RESULTS: BIA-derived ICW estimates explained 58% to 73% of the observed variance in ICW (TBK), but limits of confidence were wide (-16.6 to +18.2% for the best method). BIA overestimated low ICW (TBK) and underestimated high ICW (TBK) when normalized for weight or height. Mono- and multifrequency BIA were not different in precision but population-specific equations tended to narrower confidence limits. CONCLUSION: BIA is an unreliable method to estimate ICW in this population, in contrast to the better established estimation of total body water and extracellular water. Potassium depletion in severe malnutrition may contribute to this finding but a major part of the residual between methods remains unexplained.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Follow-up of differentiated thyroid cancer: comparison of multiple diagnostic tests.

The radioablation of thyroid remnants improves the prognosis of differentiated thyroid cancer. In our prospective study an activity of 3.7 GBq 131I failed to completely ablate the remnants in 46 out of 101 patients, but a 3-year follow-up period was uneventful. One other patient had a recurrence early after thyroidectomy. In view of possible stunning effects of 131I it might be advantageous to visualize such remnants by imaging modalities which do not emit beta-particles. Our data have revealed that neither magnetic resonance imaging (MRI), nor ultrasonography (US), nor 99Tcm-sestamibi scintigraphy, nor positron emission tomography could detect or reliably exclude minimal remnants. Such remnants did not produce thyroglobulin (Tg). A 123I and 131I uptake of> 10% after thyroidectomy was associated with about a 90% probability of persistent remnants. On the other hand, MRI was helpful in the patient group (n = 32) with Tg>4ng x ml(-1) at the second whole-body scintigraphy (TSH>30 mU x l(-1)) for planning the management of lymph node metastases (n = 15 patients): 12 patients had subsequent surgery and three patients radioiodine therapy. We recommend that MRI be used early in follow-up care when Tg is elevated. The decision of whether or not to treat persistent thyroid remnants should not be made on the basis of MRI, US or nonspecific scintigraphic methods. Complete ablation did not appear to have any clinical benefit in our study group.

Adolescent↗
PubMed1998

[Exposure of relatives of patients after stationary radioiodine therapy by inhalation of 131I in their homes].

AIM: From a model of iodine metabolism exhalation coefficients shall become derived to calculate 131I exhalation by patients after a radioiodine treatment. The validity of these exhalation coefficients shall be reviewed by whole body activity measurements of relatives of patients, who inhaled the radioiodine exhaled by the patients in their homes. The exposure of relatives to patients of a nuclear medical ward after release by exhalation of iodine-131 is investigated. METHODS: Iodine 131I-activity of 17 relatives to patients who had to undergo a radioiodine therapy became measured in a whole body counter only a few days after release of the patient from the nuclear medical ward. The results of the measurements have been compared with the results of calculations according to the model of iodine metabolism. RESULTS: The calculated values of incorporated radioiodine in the relatives of the patient at time of measurement (Amodel) correlate with the measured whole body activity (AGK) according to the regression: Amodel = AGK -47.3 (r2 = 0.959). This relation holds if 2.1 micrograms of iodine become exhaled per day of the 60 micrograms of iodine which are the daily intake of iodine by food. The exposure of all relatives did never exceed 100 microSveff. Using the same model parameters the effective dose equivalent of the relatives to our patients rises up to 6.5 mSv under ambulant radio therapy condition. CONCLUSION: The daily exhalation of 131I is able to be calculated by a mathematical model of iodine metabolism. After staying of patients at least 3 days in a nuclearmedical ward the exposure of relatives of patients in their home does not exceed the value of 100 microSveff by inhalation of iodine-131. This are 10% of the limit of 1 mSveff according to the Recommendations of the Commission on Radiological Protection (ICRP 60). Radioiodine therapy outside of a hospital and "iodine therapy tourisme" of German patients to other countries cannot be accepted.

Air Pollution, Indoor↗
PubMed1998

[Influence of disease prognosis and age on the radiation risk from diagnostic nuclear medicine (bone scintigraphy as an example)].

AIM: Of the study was to assess the influence of the patient age and the survival of patients undergoing bone scintigraphy on the calculations of the theoretical lifetime loss. PATIENTS AND METHODS: The evaluated data set included 216 patients undergoing a bone scan for the first time in 1980. From 182 patients a study end point (either the date of death, or existing registration in the German resident office on the 31.12.1995) was obtained. The theoretical life time loss was based on the formalism previously presented by Schicha und Wellner (13). RESULTS: In 74% of the examined patients a malignant disease was present. 28% of the patients had died within one year of the examination. At the end of the follow-up period, of at least 15 years, 58% of the patients were deceased. The theoretical lifetime loss due to radiation exposure within this specified patient group was estimated to be 0.152 d/mSv. Assuming an age distribution of the general population and statistically derived life expectancy, this value should be 0.437 d/mSv. CONCLUSION: The estimates regarding the risk of diagnostic procedures using ionizing radiation should take into account the limited life expectancy of patients in hospitals.

Adolescent↗