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Magnetic resonance imaging (MRI) misses a proportion of "clinically significant" prostate cancers (csPC) as defined by histopathology criteria. The aim of this study was to analyze whether long-term oncologic outcomes differ between MRI-detectable and MRI-occult csPC.Retrospective analysis of 1449 patients with pre-prostatectomy MRI and csPC on prostatectomy specimens (ie, Grade group ≥2 or extraprostatic spread) between 2001-2006. T2-weighted MRIs were classified according to the Prostate Imaging Reporting and Data System into MRI-occult (categories 1, 2), MRI-equivocal (category 3), and MRI-detectable (categories 4, 5). Cumulative incidence of biochemical recurrence (BCR), metastatic disease, and cancer-specific mortality, estimated with competing risk models. The median follow-up in survivors was 11.0 years (IQR: 8.9-13.1).In 188 (13%) cases, csPC was MRI-occult, 435 (30%) MRIs were equivocal, and 826 (57%) csPC were MRI-detectable. The 15-year cumulative incidence [95% CI] of BCR was 8.3% [2.2, 19.5] for MRI-occult cases, 17.4% [11.1, 24.8] for MRI-equivocal cases, and 43.3% [38.7, 47.8] for MRI-detectable cases (P.001). The cumulative incidences of metastases were 0.61% [0.06, 3.1], 3.5% [1.5, 6.9], and 19.6% [15.4, 24.2] for MRI-occult, MRI-equivocal, and MRI-detectable cases, respectively (P.001). There were no deaths from prostate cancer observed in patients with MRI-occult csPC, compared to an estimated 1.9% [0.54, 4.9], and 7.1 % [4.5, 10.6] for patients with MRI-equivocal and MRI-detectable cancer, respectively (P.001).Oncologic outcomes after prostatectomy for csPC differ between MRI-occult and MRI-detectable lesions. Judging the clinical significance of a negative prostate MRI based on histopathologic surrogates alone might be misleading.Among 1449 patients with pre-prostatectomy MRI and clinically significant prostate cancer on prostatectomy histopathology, MRI-occult cancers (n = 188, 13%) were less likely to recur biochemically (8% vs. 43%, P.001), metastasize (0.6% vs. 20%, P.001), or lead to prostate cancer mortality (0% vs. 7%, P.001) than MRI-detectable cancers (n = 826, 57%). MRI-occult cancers constitute a prognostically distinct subgroup among higher-grade prostate cancers.

The use of magnetic resonance imaging (MRI) for radiation therapy simulation is growing because of its ability to provide excellent delineation of target tissue and organs at risk. With the use of hypofractionated schemes in prostate cancer, urethral sparing is essential; however, visualization of the prostatic urethra can be challenging because of the presence of benign prostatic hyperplasia as well as respiratory motion artifacts. The goal of this study was to compare the utility of 2 motion-insensitive, T2-weighted MRI pulse sequences for urethra visualization in the setting of MRI-based simulation.Twenty-two patients undergoing MRI simulation without Foley catheters were imaged on a 3 Tesla MRI scanner between October 2018 and January 2019. Sagittal multislice data were acquired using (1) MultiVane XD radial sampling with parallel imaging acceleration (MVXD) and (2) single-shot fast-spin-echo (SSFSE) sequences with acquisition times of 2 to 3 minutes per sequence. For each examination, 2 genitourinary radiologists scored prostatic urethra visibility on a 1-to-5 scale and rated the signal-to-noise ratio and the presence of artifacts in each series.Urethral visibility was scored higher in the MVXD series than in the SSFSE series in 18 of 22 cases (Reader 1) and 17 of 22 cases (Reader 2). The differences in scores between MVXD and SSFSE were statistically significant for both readers (P .0001 for both, paired Student's t-test) and interobserver agreement was high (Cohen's kappa = 0.67). Both readers found the signal-to-noise ratio of the MVXD sequence to be superior in all cases. The MVXD sequence was found to generate more artifacts than the SSFSE sequence, but these tended to appear in the periphery and did not affect the ability to visualize the urethra.A radial T2-weighted multislice pulse sequence was superior to an SSFSE sequence for visualization of the urethra in the setting of magnetic resonance simulation for prostate cancer.

We study the inverse problem in the difference Galois theory of linear differential equations over the difference-differential field $\mathbb{C}(x)$ with derivation $\frac{d}{dx}$ and endomorphism $f(x)\mapsto f(x+1)$. Our main result is that every linear algebraic group, considered as a difference algebraic group, occurs as the difference Galois group of some linear differential equation over $\mathbb{C}(x)$., 29 pages, new Section 6.2

We introduce a class of strongly \'{e}tale difference algebras, whose role in the study of difference equations is analogous to the role of \'{e}tale algebras in the study of algebraic equations. We deduce an improved version of Babbitt's decomposition theorem and we present applications to difference algebraic groups and the compatibility problem., Comment: 22 pages, minor changes, several examples added

Summary The association of brown adipose tissue (BAT) and body fat distribution and their combined effects on metabolic health in humans remains unknown. Here, we retrospectively identify individuals with and without BAT on 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and assemble a propensity score-matched study cohort to compare body fat distribution and determine its role in mediating the benefits of brown fat. We find that BAT is associated with lower amounts of visceral adipose tissue and higher amounts of subcutaneous adipose tissue, resulting in less central obesity. In addition, BAT is independently associated with lower blood glucose and white blood cell count, improved lipids, lower prevalence of type 2 diabetes mellitus, and decreased liver fat accumulation. These observations are most prominent in individuals with central obesity. Our results support a role of BAT in protection from visceral adiposity and improved metabolic health., Graphical abstract, Highlights Brown adipose tissue is associated with more subcutaneous and less visceral fat Brown adipose tissue is associated with health independent of fat distribution Brown adipose tissue is associated with less liver fat and type 2 diabetes Brown adipose tissue is most beneficial in individuals with central obesity, Wibmer et al. report that brown adipose tissue is associated with a healthier body fat distribution and less central obesity and also associated independently with surrogate parameters of metabolic health and decreased liver fat accumulation. These observations are most prominent in individuals with central obesity.

Background Open conversions (OC) due to failed endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) are technically demanding because of preexisting prostheses and advanced aortic disease. This study evaluates the feasibility and outcomes of aorto-uniiliac endografting (AUI) as an alternative treatment option in acute failed EVAR. Methods From March 1995 through February 2012, 26 patients underwent acute conversion of failed EVAR at our tertiary care university center. All data were prospectively entered in our institutional database. Outcomes included 30-day or in-hospital mortality, postoperative complications, and mid-term survival. Results During the investigation period, a total of 692 patients received EVAR at our institution, while five of the 26 patients with acute conversion (19.2%) had an initial EVAR at an outlying institution and were referred for treatment. Therefore, our estimated institutional rate of acute conversions was 3% (21 of 692 EVAR). OC were performed in 14 patients (53.8%), while 12 patients underwent AUI (46.2%). An average time of 20.3 months (median: 18.6; interquartile range Q1–Q3: 0.0–38.6) elapsed between the initial EVAR and the acute conversion. All acute AUI conversion procedures were completed successfully. The 30-day mortality following acute conversions was 42.3% and since the use of AUI, it could be reduced to 33.3%. Kaplan–Meier estimates revealed a survival advantage for AUI at one year (p = 0.046), but the benefit was lost by mid-term follow-up (p = 0.103). Conclusions AUI for the treatment of acute failed EVAR represents a feasible and less invasive alternative to OC, and is associated with better one-year survival rates.

We present a characterization of differential Picard–Vessiot extensions which is analogous to the field theoretic characterization of Galois extensions in classical Galois theory.

Aim To evaluate the value of gadoxetic acid-enhanced T1-weighted (T1W) magnetic resonance cholangiography (MRC) versus conventional T2-weighted (T2W) MRC compared to endoscopic retrograde cholangiopancreatography (ERCP) in patients with primary sclerosing cholangitis (PSC). Materials and methods Based on T1W MRC, PSC patients were classified into a regular (RG) and a delayed (DG) excreting group, with an absence of gadoxetic acid in the common bile duct at 20 min. Beading, pruning, and gradation of central bile duct stenosis, evaluated by T1W and T2W MRC, were compared to ERCP. Liver parenchymal enhancement was measured in both study groups and compared to a reference group ( n = 20) without a history of liver disease. Two readers performed all measurements. Results Based on beading and pruning of the peripheral bile ducts, sensitivities, specificities, and accuracies for reader 1 were 0.17/0.43, 0/0.17, and 0.15/0.31 for T1W MRC, and 0.83/0.86, 1/0.83, and 0.85/0.85 for T2W MRC ( p = 0.004). For reader 2 sensitivities, specificities, and accuracies were 0.25/0.57, 0/0.33, and 0.23/0.46 for T1W MRC, and 0.92/1, 1/0.83, and 0.92/0.92 for T2W MRC ( p = 0.012). Compared to ERCP, central bile duct stenoses were significantly overestimated ( p 0.001) by T2W MRC. A significantly lower parenchymal enhancement was found in the DG ( n = 7) compared to the RG ( n = 13), and compared to the reference group ( p 0.001). Conclusion The combined performance of T2W and T1W MRC may provide a comprehensive imaging workup of PSC, including morphological and functional information resulting in optimal management.

Objectives To present long-term results of endoleak/endograft migration treatment by aortomonoiliac (AMI) endografting after failed endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms. Design Post hoc analysis of a prospectively gathered database at a tertiary care university hospital. Materials and methods From March 1995 to November 2010, 23 patients were identified who underwent modification into AMI configuration after failed elective EVAR. Major causes for modification were type I (with/without endograft migration) or type III endoleaks with aneurysm expansion. An average increase in aneurysm size of 1.6 cm (range: −1.5 to 10.5 cm) since initial aneurysm treatment was observed. Interventional outcomes and long-term results were recorded for analysis. Results Technical success rate of AMI endografting was 95.65% ( n = 22). All except two endoleaks could be successfully sealed with this manoeuvre (94.44%). Median time to modification was 5.3 years (interquartile range Q1–Q3: 1.3–9.3 years). No intra-operative conversion to open surgery was necessary and mortality was 0%. Median follow-up was 44 months (interquartile range Q1–Q3: 17–69 months). Conclusions Treatment of graft-related endoleaks/endograft migration by AMI endografting after failed EVAR represents a safe and feasible procedure. This approach broadens the minimal invasive opportunities of aneurysm treatment, and open surgical conversion may be avoided except in selected patients.

The purpose of this short note is to establish the existence of ∂-parameterized Picard–Vessiot extensions for systems of linear difference-differential equations over difference-differential fields with an algebraically closed field of constants.

Purpose To compare perioperative and follow-up outcomes of symptomatic versus asymptomatic patients following endovascular repair of anastomotic pseudoaneurysms (APAs) of the abdominal aorta and iliac arteries. Methods We retrospectively evaluated 17 patients (two women), with a mean age of 66.2 years (range 30–83 years). Endovascular treatment was performed in ten symptomatic, and seven asymptomatic patients electively. Data included technical success, perioperative (within 30 days) mortality and morbidity, as well as stent graft-related complications, reinterventions, and survival in follow-up. Results Bifurcated ( n = 13), aortomonoiliac ( n = 3) endoprosthesis and one aortic cuff were implanted with a primary technical success rate of 100%. The overall in-hospital mortality and morbidity rate was 11.8% and 35.3%. The mean survival was 36.5 (range 0–111) months. There was a clear trend toward a lower overall survival within hospital and at one and three years for symptomatic patients compared to asymptomatic patients. (47.7 (CI: 0–138.8) versus 52.6 (CI: 28.5–76.8) months ( p = 0.274)). During follow-up, late stent graft related complications were observed in six patients (35.3%) necessitating eight endovascular reinterventions. Additional three patients with primary fistulas between the APA and the intestine were treated by late surgical revision. Conclusion Endovascular therapy of APAs represents a considerable alternative to open surgical repair. Short proximal anchoring zones still pose a risk for endoleaks and unintentional overstenting of side branches with commercially available devices, but this might be overcome by use of fenestrated and branched stent grafts in elective cases.

Purpose To analyze the hazard and causes of death after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms during a complete ten year follow-up. Methods This is a retrospective clinical study of 130 consecutive patients undergoing EVAR between 1995 and 1998. One-hundred twenty-one patients (93.1%) were treated with first-generation stentgrafts and nine patients (6.9%) received second-generation devices. All patients completed a follow-up of at least 10 years, unless death occurred before then. Time and causes of death were provided by the Austrian central register of deaths. Results The median follow-up was 7.6 years, and the 130 patients had 968.5 person-years of follow-up. The ten-year mortality rate was 62.3%. Cardiovascular events were the most frequent causes of death, with a 3.9 incidence rate per 100 person-years. Cancer death and death due to other causes occurred in 2.1 and 1.8 cases per 100 person-years, respectively. Lethal late aneurysm rupture happened in 4.6% (n = 6), which corresponds to an annual incidence rate of 0.6 per 100 person-years. All of those patients had been treated with first-generation devices. Conclusions Cardiovascular events were the most frequent cause of death after EVAR, followed by malignancy and other diseases. The risk of dying from secondary rupture was clearly lower than that of death due to other reasons during ten years after EVAR, even in patients with first-generation stentgrafts.

Purpose To compare 64-multi-slice-CT angiography (64-MSCTA) to color-coded duplex sonography (CCDS) in the follow-up after carotid artery stenting (CAS). Methods Thirty patients who had an MSCTA and CCDS examination prior and after CAS were included. Twelve closed-cell and 24 open-cell stents were implanted. Neointimal surface, in-stent-restenosis (ISR), stent expansion, and fracture were evaluated. In addition, the occurrence of atherosclerotic lesions leading to a > 50% stenosis in supraaortic vessels was assessed. Results With MSCTA, >50% ISR was found in 5.6% of cases during a mean follow-up of 41.7 months. Comparing MSCTA and CCDS, grading of ISR and absolute diameters of neointimal surface correlated moderately (Spearman = 0.402, p = 0.015; Pearson = 0.404, p = 0.03). Assessment of the neointimal surface was significantly better with MSCTA (100% vs. 80.6%; p = 0.011). Stent expansion was significant, compared to the basic value, with both modalities and stent types (p 50% stenosis was detected in 38 (16.0%) vessel segments. Findings were stable in 25 (10.5%) and progressed in 11 (4.6%) vessel segments. Five small intracranial aneurysms were detected in four (13.3%) patients. Of 21 incidental findings in 16 (51.6%) patients there was one with malignancy (4.8%). Conclusion With regard to ISR and stent expansion, no significant difference was found, when MSCTA and CCDS were compared. CTA is quite applicable as a complementary imaging method for the follow-up of patients with carotid artery stents. Additional advantages are the detection of supraaortic vessel pathologies and incidental findings.

Possible effects of comorbidities and of different wound etiologies on the success of extracorporeal shock wave therapy (ESWT) of chronic soft tissue wounds were investigated. From September 2003 until February 2007, 282 patients, being previously treated unsuccessfully were enrolled. Treatment consisted of ESWT occurring at defined intervals. At each treatment session a wound bed score was recorded, also at initial presentation a detailed patient history and wound etiology. Observed comorbidities were pooled according to the chapters of the ICD-10 system. Two hunderd fifty-eight patients were analyzed (91.49%) and underwent follow-up for a median of 31.8 months. Wound closure occurred in 191 patients (74.03%) by a median of two treatment sessions. No wound reappeared at the same location. A multivariate logistic regression model showed that pooled comorbidities and wound etiologies did not have a significant influence on success. Comorbidities and wound etiologies have surprisingly no significant influence on the success of ESWT.

Gröbner bases are the computational method par excellence for studying polynomial systems. In the case of parametric polynomial systems one has to determine the reduced Gröbner basis in dependence of the values of the parameters. In this article, we present the algorithm GröbnerCover which has as inputs a finite set of parametric polynomials, and outputs a finite partition of the parameter space into locally closed subsets together with polynomial data, from which the reduced Gröbner basis for a given parameter point can immediately be determined. The partition of the parameter space is intrinsic and particularly simple if the system is homogeneous.

ObjectiveForceps biopsy is the standard method to obtain specimens in endoscopically visible lesions. It is common to combine forceps biopsy with cytology methods to increase the diagnostic yield. Although the flexible cryoprobe has been established for bronchoscopic interventions in malignant stenosis, the obtained biopsies, called “cryobiopsies,” have not been investigated in a large cohort of patients. The aim of this feasibility study was to prospectively evaluate the diagnostic yield and safety of cryobiopsy and forceps biopsy.MethodsDuring a 6-year period, 296 patients with visible endoluminal tumor lesions were included in the study at the bronchoscopy unit of a university hospital. In the first consecutively conducted 55 cases, both techniques, forceps biopsy and cryobiopsy, were applied simultaneously. Pathologic and quantitative image analyses were performed to evaluate the size and quality of the obtained specimens. We evaluated the safety and diagnostic yield to describe the feasibility of cryobiopsy.ResultsComparative analysis of the first conducted and randomly assigned 55 cases revealed a significantly higher diagnostic yield for cryobiopsy compared with forceps biopsy (89.1% vs 65.5%, P < .05). In this cohort, quantitative image analysis showed significantly larger biopsies regarding size and artifact-free tissue sections for cryobiopsy compared with forceps biopsy (P < .0001). The overall diagnostic yield of cryobiopsy was 89.5%. Mild bleeding occurred in 11 cases (3.7%), moderate bleeding occurred in 3 cases (1.0%), and severe bleeding occurred in 1 case (0.3%).ConclusionCryobiopsy is safe and increases the diagnostic yield in endobronchial tumor lesions. The method also is feasible under routine conditions.

Objective In addition to use of a laser, argon plasma coagulation, electrocautery, or coring with a rigid bronchoscope, tumor debulking with a flexible cryoprobe is used for therapeutic bronchoscopy with an immediate effect for endobronchial pathologies. We performed this analysis to determine the usefulness, efficacy, and safety of the flexible cryorecanalization in a large population under routine conditions. Methods We identified 225 bronchoscopic interventions that were done as cryorecanalization with a flexible cryoprobe. All patients had symptomatic airway stenosis. We determined the endoscopic success rate and safety (bleeding and perforation) of the procedure. Results Successful cryorecanalization was achieved in 205 (91.1%) of 225 patients. The flexible cryoprobe was used with all patients, in most patients in combination with flexible bronchoscopy and only in a minority (n = 31, 13.8%) in combination with a rigid bronchoscope. Additional interventional techniques used were endobronchial stents (n = 11, 4.9%) and argon plasma coagulation (n = 37, 16.4%). Mild bleeding (if ice-cold NaCl or epinephrine solution was necessary) occurred in 9 (4.0%) patients, moderate bleeding (if argon plasma coagulation or a bronchus blocker was required) occurred in 18 (8.0%) patients, and severe bleeding (events with hemodynamic instability) never occurred. Conclusions Cryorecanalization with the flexible cryoprobe for treatment of symptomatic endobronchial tumor stenosis is a safe technique with a high success rate and immediate treatment effect.

Summary Background Aim of this study was to evaluate efficacy, toxicity and tolerability of chemotherapy with a combination of mitomycin and vinorelbine (M/V) in patients with advanced non-small cell lung cancer (NSCLC). Methods We enrolled 110 patients (median age 67 years) with locally advanced or metastatic NSCLC, who had no prior chemotherapy or progressive disease after at least one prior chemotherapy regimen. 45 patients (41%) were ≥70 years old. All patients received vinorelbine 25mg/m 2 (d1,8) and mitomycin 8mg/m 2 (d1) every 3–4 weeks. Restaging was performed by CT-scan after every two courses M/V according to RECIST criteria. Results M/V was well tolerated, even in patients with a poor performance status or ≥70 years Median progression free survival was 4.4 months. Median overall survival was 9.0 months with a 1-year survival rate of 39%. Partial response was observed in 15% and stable disease in 51% of patients. Both hematological and non-hematological toxicities were generally mild. CTC grade 3 toxicities observed included neutropenia in 3%, anemia in 3%, thrombocytopenia in 1% and suspected pneumonitis in 2% of patients. Except neutropenia in 2% and acute dyspnea in 1%, there were no other grade 4 toxicities and no treatment associated casualties. There was no relevant difference in outcome or toxicity between patients ≥70 and Conclusions M/V seems to be a well-tolerated and effective chemotherapy regimen with low toxicity in patients with advanced NSCLC. It seems to be an interesting option even for patients ≥70 years or with a reduced performance status.

Let I be an ideal of the polynomial ring A[x]=A[x"1,...,x"n] over the commutative, Noetherian ring A. Geometrically, I defines a family of affine schemes, parameterized by Spec(A): For [email protected]?Spec(A), the fibre over p is the closed subscheme of the affine space over the residue field k(p), which is determined by the extension of I under the canonical map @s"p:A[x]->k(p)[x]. If I is homogeneous, there is an analogous projective setting, but again the ideal defining the fibre is . For a chosen term order, this ideal has a unique reduced Grobner basis which is known to contain considerable geometric information about the fibre. We study the behavior of this basis for varying p and prove the existence of a canonical decomposition of the base space Spec(A) into finitely many, locally closed subsets over which the reduced Grobner bases of the fibres can be parametrized in a suitable way.

Purpose Accurate identification of the source of a detectable serum prostate-specific antigen (PSA) in the postprostatectomy setting is a major challenge among the urologic community. The aim of this study was to assess positivity rates of imaging examinations performed in patients with early PSA rise after prostatectomy and to summarize the management strategies adopted in this clinical scenario. Methods Institutional Review Board-approved retrospective study of 142 postprostatectomy patients with PSA rise up to 1 ng/ml who underwent evaluation with combination of multiparametric pelvic magnetic resonance imaging (MRI)±whole-body or bone MRI, bone scintigraphy, computed tomography (CT) chest-abdomen-pelvis, 18 F-fludeoxyglucose-positron emission tomography (PET)/CT or 18 F-sodium fluoride-PET/CT at a single tertiary cancer center. Imaging results were summarized per modality and compared with pathology findings. Results Pelvic MRI was positive in 15/142 (11%) patients (14 patients with local recurrence in the surgical bed and 1 patient with pelvic osseous metastases). Of these 15, 10 patients underwent additional imaging examinations; none revealed positive findings. Of the 127 patients with negative pelvic MRI, 54 (43%) underwent additional imaging examinations; only 1/54 had positive findings (false-positive T8 lesion on bone scintigraphy and FDG-PET/CT; biopsy was negative for cancer). Overall, 12/16 patients with positive imaging findings and 75/126 (60%) patients with negative imaging received treatment (radiation, hormones or chemotherapy). Conclusion The conventional imaging identified sites of disease, almost always in the form of local recurrence, in a minority of patients with early PSA rise postprostatectomy.

Start-up firms typically produce negative cash flows in the first years after their foundation. As a consequence, standard discounted cash flow methods are not applicable, often forcing practioneers into using theoretically dissatisfying devices like multiples. In this paper, we develop a comprehensive and theoretically more convincing valuation framework for start-up firms. Our analysis is based on a contingent claims approach in an arbitrage-free setting which - due to an alternative process assumption - explicitly allows for the negative earnings typically produced by start-up businesses in early stages of their development. The model allows for the derivation of optimal conditions for exercising the waiting option to invest in a start-up as well as its optimal capital structure upon establishment. Finally, we show how unexercised additional options to invest (growth options) - even if producing negative cash flows at the time of investment - may significantly contribute to the start-up firm's value. The explicit incorporation of additional investment options may serve as an explanation for observable high market values of start-up firms with low or negative current cash flows.