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Oldenburg, Germany

De Wilde R.L.,Pius Hospital | Brosens I.,Catholic University of Leuven
Human Reproduction | Year: 2012

The transvaginal access for exploration of tubo-ovarian function in women with unexplained infertility has been revived since transvaginal hydrolaparoscopy (THL) was introduced in 1998. One prospective double-blind trial and several reviews have validated the diagnostic value of THL in comparison with laparoscopy for the exploration of women with unexplained infertility. A review of the recent literature confirms the efficacy and safety of the technique for first-line endoscopy-based exploration of fertility. The standard policy of 1-year delay for laparoscopic investigation in unexplained infertility is challenged. In older women and particularly in women experienced in fertility awareness methods, THL and minihysteroscopy can be performed after a waiting period of 6-12 months. © The Author 2012. Source


Poppe B.,Carl von Ossietzky University | Looe H.K.,Carl von Ossietzky University | Chofor N.,Carl von Ossietzky University | Ruhmann A.,Carl von Ossietzky University | And 2 more authors.
Radiotherapy and Oncology | Year: 2010

Background and purpose: Clinical evaluation of a novel dosimetric accessory serving the permanent supervision of MLC function. Materials and methods: The DAVID system (PTW-Freiburg, Germany) is a transparent, multi-wire transmission ionization chamber, placed in the accessory holder of the treatment head. Since each of the 37 individual wires is positioned exactly below the associated leaf pair of the MLC, its signal records the opening of this leaf pair during patient treatment. Results: The DAVID system closes a gap in the quality assurance program, permitting the permanent invivo verification of IMRT plans. During dosimetric plan verification with the 2D-ARRAY (PTW-Freiburg Germany), reference values of the 37 DAVID signals are collected, with which the DAVID readings recorded during daily patient treatment are compared. This comparison is visually displayed in the control room, and warning and alarm levels of any discrepancies can be defined. The properties of the DAVID system as a transmission device, its sensitivity to beam delivery and leaflet errors as well as its stability have been analyzed for clinically relevant examples. In a recent version, the DAVID system has been equipped with 80 wires. Conclusions: The DAVID system permits the on-line detection of clinically relevant MLC discrepancies in IMRT deliveries. © 2010 Elsevier Ireland Ltd. All rights reserved. Source


Hohloch K.,University of Gottingen | Bertram N.,University of Gottingen | Trumper L.,University of Gottingen | Beissbarth T.,University of Gottingen | Griesinger F.,Pius Hospital
Journal of Cancer Research and Clinical Oncology | Year: 2014

Purpose: Superior vena cava syndrome (SVCS) results from compression of the superior vena cava. SVCS is an emergency requiring immediate diagnosis and treatment. We hypothesized that the outcome of patients (pts.) admitted during regular work hours may differ from that of pts. admitted on weekends. Methods: From 1992 to 2011, we analyzed all pts. admitted with SVCS due to a malignancy. Clinical outcome was analyzed, focusing on the work-up of pts. hospitalized on a weekend compared with those hospitalized during the week. Results: One hundred and twenty-four pts. with malignant causes of SVCS were analyzed. Causes were as follows: small cell lung cancer (SCLC) 28.2 %, non-small cell lung cancer 25 %, non-Hodgkin’s lymphoma 25 %, metastasis of other malignant tumors 19.4 % and Hodgkin’s disease 2.4 %. Sixty-five percent of pts. were admitted during the week and 35 % on a weekend. Sixty-one percent received chemotherapy, 24 % radiation, 4 % radiochemotherapy, 9 % palliative treatment and 2 % no treatment at all. No difference in choice of treatment between pts. admitted on a weekday versus weekend was seen. Response was as follows: 7 pts. complete remission, 20 pts. partial response, 38 pts. progressive disease, 3 pts. NC and 15 pts. died. Overall response rate was as follows: Hodgkin’s disease 100 %, non-Hodgkin’s lymphoma 29 %, SCLC 22.8 %, non-small cell lung cancer 9.6 % and metastatic cancer 16.6 %. Only 2 of the 34 pts. with relapsing carcinoma responded. None of the pts. died due to SVCS. Conclusion: The outcome of pts. with SVCS is not dependent on the day of admission (weekend or weekday) but is related to underlying disease in the setting of a tertiary care center. © 2014, Springer-Verlag Berlin Heidelberg. Source


Maier G.S.,Justus Liebig University | Maier G.S.,Johannes Gutenberg University Mainz | Maier G.S.,Universitatsklinikum Giessen | Jakobs P.,Johannes Gutenberg University Mainz | And 3 more authors.
Clinical Orthopaedics and Related Research | Year: 2013

Background: Vitamin D plays an essential role in bone health and muscle function. Some studies have shown a widespread rate of vitamin D deficiency in the general population, but few have reported on the vitamin D status of orthopaedic patients. Questions/purposes: We investigated (1) the extent of hypovitaminosis D in orthopaedic patients, (2) seasonal variations in vitamin D levels, and (3) possible risk factors for insufficient vitamin D levels. Methods: Vitamin D levels in 1119 patients consecutively admitted to an orthopaedic surgery department in 2011 were measured. To investigate the correlation between climate factors and vitamin D levels, the sunshine hours for each month in 2011 were collected by Deutscher Wetterdienst (the German weather service) in the region where most tested patients lived. The prevalence of normal (> 30 ng/mL), insufficient (20-30 ng/mL), and deficient (< 20 ng/mL) 25-hydroxyvitamin D levels was determined. Univariate and multivariate analyses were used to assess risk factors for insufficient vitamin D levels. Results: Overall, 84% of patients had insufficient levels of vitamin D and 60% were vitamin D deficient. Only 15% were in the target range of 30 to 60 ng/mL. The prevalence of low vitamin D levels was greater during winter and months with fewer sunshine hours. Vitamin D levels did not vary according to age, sex, and disease. Individuals with obesity, hypertension, and osteoporosis were more likely to have low vitamin D levels compared with their healthy counterparts. Conclusions: There is an alarmingly high rate of hypovitaminosis D and vitamin D deficiency among orthopaedic patients in this region of Germany, whose latitude (50 N) is approximately the same as those of Vancouver (49, 15' N) and Paris (48, 51' N). Given the well-known effects on bone metabolism and muscle health, low vitamin D levels may negatively affect patients. Screening and treating hypovitaminosis D appears to be important in this patient population. Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence. © 2013 The Association of Bone and Joint Surgeons®. Source


Chofor N.,Carl von Ossietzky University | Harder D.,University of Gottingen | Willborn K.,Pius Hospital | Ruhmann A.,Carl von Ossietzky University | Poppe B.,Carl von Ossietzky University
Physics in Medicine and Biology | Year: 2011

A new concept for the design of flattening filters applied in the generation of 6 and 15 MV photon beams by clinical linear accelerators is evaluated by Monte Carlo simulation. The beam head of the Siemens Primus accelerator has been taken as the starting point for the study of the conceived beam head modifications. The direction-selective filter (DSF) system developed in this work is midway between the classical flattening filter (FF) by which homogeneous transversal dose profiles have been established, and the flattening filter-free (FFF) design, by which advantages such as increased dose rate and reduced production of leakage photons and photoneutrons per Gy in the irradiated region have been achieved, whereas dose profile flatness was abandoned. The DSF concept is based on the selective attenuation of bremsstrahlung photons depending on their direction of emission from the bremsstrahlung target, accomplished by means of newly designed small conical filters arranged close to the target. This results in the capture of large-angle scattered Compton photons from the filter in the primary collimator. Beam flatness has been obtained up to any field cross section which does not exceed a circle of 15 cm diameter at 100 cm focal distance, such as 10 × 10 cm2, 4 × 14.5 cm2 or less. This flatness offers simplicity of dosimetric verifications, online controls and plausibility estimates of the dose to the target volume. The concept can be utilized when the application of small- and medium-sized homogeneous fields is sufficient, e.g. in the treatment of prostate, brain, salivary gland, larynx and pharynx as well as pediatric tumors and for cranial or extracranial stereotactic treatments. Significant dose rate enhancement has been achieved compared with the FF system, with enhancement factors 1.67 (DSF) and 2.08 (FFF) for 6 MV, and 2.54 (DSF) and 3.96 (FFF) for 15 MV. Shortening the delivery time per fraction matters with regard to workflow in a radiotherapy department, patient comfort, reduction of errors due to patient movement and a slight, probably just noticable improvement of the treatment outcome due to radiobiological reasons. In comparison with the FF system, the number of head leakage photons per Gy in the irradiated region has been reduced at 15 MV by factors 1/2.54 (DSF) and 1/3.96 (FFF), and the source strength of photoneutrons was reduced by factors 1/2.81 (DSF) and 1/3.49 (FFF). © 2011 Institute of Physics and Engineering in Medicine. Source

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