32 research outputs found
When OT meets MoM: Robust estimation of Wasserstein Distance
No full textOriginated from Optimal Transport, the Wasserstein distance has gained importance in Machine Learning due to its appealing geometrical properties and the increasing availability of efficient approximations. It owes its recent ubiquity in generative modelling and variational inference to its ability to cope with distributions having non overlapping support. In this work, we consider the problem of estimating the Wasserstein distance between two probability distributions when observations are polluted by outliers. To that end, we investigate how to leverage a Medians of Means (MoM) approach to provide robust estimates. Exploiting the dual Kantorovitch formulation of the Wasserstein distance, we introduce and discuss novel MoM-based robust estimators whose consistency is studied under a data contamination model and for which convergence rates are provided. Beyond computational issues, the choice of the partition size, i.e., the unique parameter of theses robust estimators, is investigated in numerical experiments. Furthermore, these MoM estimators make Wasserstein Generative Adversarial Network (WGAN) robust to outliers, as witnessed by an empirical study on two benchmarks CIFAR10 and Fashion MNIST
Radical prostatectomy for low-risk prostate cancer following initial active surveillance : results from a prospective observational study
No full textBACKGROUND:
Little is known about the outcome of radical prostatectomy (RP) in men initially followed on active surveillance (AS) for low-risk prostate cancer (PCa).
OBJECTIVE:
Evaluate pathology findings after RP in our prospective AS cohort.
DESIGN, SETTING, AND PARTICIPANTS:
All men participated in the Prostate Cancer Research International: Active Surveillance (PRIAS) study. Eligible men were initially diagnosed with low-risk PCa (clinical stage ≤ T2, prostate-specific antigen [PSA] ≤ 10 ng/ml, PSA density <0.2 ng/ml per ml, one or two positive biopsy cores, and Gleason score ≤ 6) and underwent RP between December 2006 and July 2011. The study protocol recommends RP in case of risk reclassification on repeat biopsy (Gleason score >6 and/or more than two positive cores) or a PSA doubling time ≤ 3 yr.
MEASUREMENTS:
Descriptive statistics were used to report on pathology findings for staging and grading.
RESULTS AND LIMITATIONS:
Pathology results were available in 167 out of 189 RP cases (88.4%). Median time to RP was 1.3 yr (range: 1.1-1.9). Protocol-based recommendations led to deferred RP in 143 men (75.7%); 24 men (12.7%) switched because of anxiety, and 22 (11.6%) had other reasons. Pathology results showed 134 (80.8%) organ-confined cases and 32 (19.2%) cases with extracapsular extension. Gleason scores ≤ 6, 3+4, 4+3, and 8 were found in 79 (47.3%), 64 (38.3%), 21 (12.6%), and 3 (1.8%) cases, respectively. Unfavourable RP results (pT3-4 and/or Gleason score ≥ 4+3) were found in 49 patients (29%), of whom 33 (67%) had a biopsy-related reason for deferred RP.
CONCLUSIONS:
RP results in men initially followed on AS show organ-confined disease and favourable Gleason grading in a majority of cases. Most men in our cohort had a protocol-based reason to switch to deferred RP. A main focus for AS protocols should be to improve the selection of patients at the time of inclusion to minimise reclassification of risk and preserve the chance for curative treatment, if indicated
What is the effect of MRI with targeted biopsies on the rate of patients discontinuing active surveillance? A reflection of the use of MRI in the PRIAS study
Get PDFBackground: The reduction of overtreatment by active surveillance (AS) is limited in patients with low-risk prostate cancer (PCa) due to high rates of patients switching to radical treatment. MRI improves biopsy accuracy and could therewith affect inclusion in or continuation of AS. We aim to assess the effect of MRI with target biopsies on the total rate of patients discontinuing AS, and in particular discontinuation due to Grade Group (GG) reclassification. Methods: Three subpopulations included in the prospective PRIAS study with GG 1 were studied. Group A consists of patients diagnosed before 2009 without MRI before or during AS. Group B consists of patients diagnosed without MRI, but all patients underwent MRI within 6 months after diagnosis. Group C consists of patients who underwent MRI before diagnosis and during follow-up. We used cumulative incidence curves to estimate the rates of discontinuation. Results: In Group A (n = 500), the cumulative probability of discontinuing AS at 2 years is 27.5%; GG reclassification solely accounted for 6.9% of the discontinuation. In Group B (n = 351) these numbers are 30.9 and 22.8%, and for Group C (n = 435) 24.2 and 13.4%. The three groups were not randomized, however, baseline characteristics are highly comparable. Conclusions: Performing an MRI before starting AS reduces the cumulative probability of discontinuing AS at 2 years. Performing an MRI after already being on AS increases the cumulative probability of discontinuing AS in comparison to not performing an MRI, especially because of an increase in GG reclassification. These results suggest that the use of MRI could lead to more patients being considered unsuitable for AS. Considering the excellent long-term cancer-specific survival of AS before the MRI era, the increased diagnostic accuracy of MRI could potentially lead to more overtreatment if definitions and treatment options of significant PCa are not adapted
Acta Antiqua
No full text1958 / 1-2. sz. 1
K. MARÓT: Der Hexameter
I. VENEDIKOV: Sur la date et l'origine du trésor de Panagurišté
J. HARMATTA: Die parthischen Ostraka aus Dura-Europos
G. ALFÖLDY: Collegium-Organisationen in Intercisa
I. Han: K voproszü o szocialnüh osznovah uzurpacii Prokopijá
G. DÉVAI: The musical study of Koukouzeles in a 14th century manuscript
D. KIENAST: Cato der Censor. Seine Persönlichkeit und seine Zeit (E. Maróti)
A. BRIESSMANN: Tacitus und das flavische Geschichtsbild (I. Borzsák)
1958 / 3-4. sz. 253
F. TŐKEI: Les conditions de la propriété fonciere dans la Chine de l'époque Tcheou
P. MUSIOLEK: Themistokles und Athen
I. TRENCSÉNYI-WALDAPFEL: Cicéron et Lucrece
I. K. HORVÁTH: Impius Aeneas
J. FITZ: Herkunft und Ethnikum der Eravisker
T. NAGY: Das Mithras-Relief von Paks
G. ALFÖLDY: Augustalen- und Servirkörperschaften in Pannonien
E. M. STAERMAN: Krizisz rabovlagyelcseszkogo sztorija v zapadüh provincijah rimszkoj imperii (I. Han
MP-06.13: Outcomes and complications of botulinum toxin-A in non-neurogenic detrusor overactivity refractory to anticholinergics
No full textUP-2.34: Impact on quality of life of botulinum toxin-a in non-neurogenic detrusor overactivity refractory to anticholinergics
No full textA Multivariable Approach Using Magnetic Resonance Imaging to Avoid a Protocol-based Prostate Biopsy in Men on Active Surveillance for Prostate Cancer-Data from the International Multicenter Prospective PRIAS Study
Get PDFBackground: There is ongoing discussion whether a multivariable approach including magnetic resonance imaging (MRI) can safely prevent unnecessary protocol-advised repeat biopsy during active surveillance (AS). Objective: To determine predictors for grade group (GG) reclassification in patients undergoing an MRI-informed prostate biopsy (MRI-Bx) during AS and to evaluate whether a confirmatory biopsy can be omitted in patients diagnosed with upfront MRI. Design, setting, and participants: The Prostate cancer Research International: Active Surveillance (PRIAS) study is a multicenter prospective study of patients on AS (www.prias-project.org). We selected all patients undergoing MRI-Bx (targeted ± systematic biopsy) during AS. Outcome measurements and statistical analysis: A time-dependent Cox regression analysis was used to determine the predictors of GG progression/reclassification in patients undergoing MRI-Bx. A sensitivity analysis and a multivariable logistic regression analysis were also performed. Results and limitations: A total of 1185 patients underwent 1488 MRI-Bx sessions. The time-dependent Cox regression analysis showed that age (per 10 yr, hazard ratio [HR] 0.84 [95% confidence interval {CI} 0.71-0.99]), MRI outcome (Prostate Imaging Reporting and Data System [PIRADS] 3 vs negative HR 2.46 [95% CI 1.56-3.88], PIRADS 4 vs negative HR 3.39 [95% CI 2.28-5.05], and PIRADS 5 vs negative HR 4.95 [95% CI 3.25-7.56]), prostate-specific antigen (PSA) density (per 0.1 ng/ml cm3, HR 1.20 [95% CI 1.12-1.30]), and percentage positive cores on the last systematic biopsy (per 10%, HR 1.16 [95% CI 1.10-1.23]) were significant predictors of GG reclassification. Of the patients with negative MRI and a PSA density of <0.15 ng/ml cm3 (n = 315), 3% were reclassified to GG ≥2 and 0.6% to GG ≥3. At the confirmatory biopsy, reclassification to GG ≥2 and ≥3 was observed in 23% and 7% of the patients diagnosed without upfront MRI and in 19% and 6% of the patients diagnosed with upfront MRI, respectively. The multivariable analysis showed no significant difference in upgrading at the confirmatory biopsy between patients diagnosed with or without upfront MRI. Conclusions: Age, MRI outcome, PSA density, and percentage positive cores are significant predictors of reclassification at an MRI-informed biopsy. Patients with negative MRI and a PSA density of <0.15 ng/ml cm3 can safely omit a protocol-based prostate biopsy, whereas in other patients, a multivariable approach is advised. Being diagnosed with upfront MRI appears not to significantly affect reclassification risk; hence, a confirmatory MRI-Bx cannot totally be omitted yet. Patient summary: A protocol-based prostate biopsy while on active surveillance can be omitted in patients with negative magnetic resonance imaging (MRI) and prostate-specific antigen density <0.15 ng/ml cm3. A confirmatory biopsy cannot simply be omitted in all patients diagnosed with upfront MRI
Endothéline-1 et récepteur A : valeur pronostique pour la reprise évolutive biologique dans l’adénocarcinome de prostate localement avancé et métastatique ganglionnaire
No full textTreatment of Primary Vesicoureteric Reflux by Polytetrafluoroethylene Injection: A Middle-Term Follow-Up Study
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