Use of EORTC Target Definition Guidelines for Dose-Intensified Salvage Radiation Therapy for Recurrent Prostate Cancer: Results of the Quality Assurance Program of the Randomized Trial SAKK 09/10

PURPOSE Different international target volume delineation guidelines exist and different treatment techniques are available for salvage radiation therapy (RT) for recurrent prostate cancer, but less is known regarding their respective applicability in clinical practice. METHODS AND MATERIALS A randomized phase III trial testing 64 Gy vs 70 Gy salvage RT was accompanied by an intense quality assurance program including a site-specific and study-specific questionnaire and a dummy run (DR). Target volume delineation was performed according to the European Organisation for the Research and Treatment of Cancer guidelines, and a DR-based treatment plan was established for 70 Gy. Major and minor protocol deviations were noted, interobserver agreement of delineated target contours was assessed, and dose-volume histogram (DVH) parameters of different treatment techniques were compared. RESULTS Thirty European centers participated, 43% of which were using 3-dimensional conformal RT (3D-CRT), with the remaining centers using intensity modulated RT (IMRT) or volumetric modulated arc technique (VMAT). The first submitted version of the DR contained major deviations in 21 of 30 (70%) centers, mostly caused by inappropriately defined or lack of prostate bed (PB). All but 5 centers completed the DR successfully with their second submitted version. The interobserver agreement of the PB was moderate and was improved by the DR review, as indicated by an increased κ value (0.59 vs 0.55), mean sensitivity (0.64 vs 0.58), volume of total agreement (3.9 vs 3.3 cm(3)), and decrease in the union volume (79.3 vs 84.2 cm(3)). Rectal and bladder wall DVH parameters of IMRT and VMAT vs 3D-CRT plans were not significantly different. CONCLUSIONS The interobserver agreement of PB delineation was moderate but was improved by the DR. Major deviations could be identified for the majority of centers. The DR has improved the acquaintance of the participating centers with the trial protocol.

Impact of definitions of loss to follow-up (LTFU) in antiretroviral therapy program evaluation: variation in the definition can have an appreciable impact on estimated proportions of LTFU

OBJECTIVE To examine the impact of different definitions of loss to follow-up (LTFU) on estimates of program outcomes in cohort studies of patients on antiretroviral therapy (ART). STUDY DESIGN AND SETTING We examined the impact of different definitions of LTFU using data from the International Epidemiological Databases to Evaluate AIDS-Southern Africa. The reference approach, Definition A, was compared with five alternative scenarios that differed in eligibility for analysis and the date assigned to the LTFU outcome. Kaplan-Meier estimates of LTFU were calculated up to 2 years after starting ART. RESULTS Estimated cumulative LTFU were 14% and 22% at 12 and 24 months, respectively, using the reference approach. Differences in the proportion LTFU were reported in the alternative scenarios with 12-month estimates of LTFU varying by up to 39% compared with Definition A. Differences were largest when the date assigned to the LTFU outcome was 6 months after the date of last contact and when the site-specific definition of LTFU was used. CONCLUSION Variation in the definitions of LTFU within cohort analyses can have an appreciable impact on estimated proportions of LTFU over 2 years of follow-up. Use of a standardized definition of LTFU is needed to accurately measure program effectiveness and comparability between programs.

Improving Management of Distributed Services Using Correlations and Predictions in SLA-Driven Cloud Computing Systems

Recent advancements in cloud computing have enabled the proliferation of distributed applications, which require management and control of multiple services. However, without an efficient mechanism for scaling services in response to changing environmental conditions and number of users, application performance might suffer, leading to Service Level Agreement (SLA) violations and inefficient use of hardware resources. We introduce a system for controlling the complexity of scaling applications composed of multiple services using mechanisms based on fulfillment of SLAs. We present how service monitoring information can be used in conjunction with service level objectives, predictions, and correlations between performance indicators for optimizing the allocation of services belonging to distributed applications. We validate our models using experiments and simulations involving a distributed enterprise information system. We show how discovering correlations between application performance indicators can be used as a basis for creating refined service level objectives, which can then be used for scaling the application and improving the overall application's performance under similar conditions.

Definition einer kritischen Situation im Fussball - Ergebnisse einer Experten-Fokusgruppe

Einleitung Bei der Untersuchung von Ausschreitungen bei Fußballspielen sind kritische Situationen (KS) interessant, die sich durch eine erhöhte Spannung auszeichnen, aber nicht immer in Gewalt enden. Es stellt sich die Frage, an welchen Merkmalen eine KS in situ erkannt werden kann, und ob dies mit theoretischen Erklärungen verglichen werden kann, wie z.B. mit dem Aggravation and Mitigation Model (Hylander & Guvå, 2010). Methode Um Kriterien einer KS festzulegen, wurde eine Fokusgruppe (Bohnsack, 2007) mit fünf Experten für Zuschauergewalt durchgeführt: zwei Polizisten mit Leitungsfunktion, zwei Fanarbeiter sowie ein Fanverantwortlicher eines Fussballstadions. In der ersten Phase gestalteten die Teilnehmer die Diskussion nach einer offenen einleitenden Frage möglichst autonom. In der zweiten Phase stellte die Moderatorin Fragen zur Klärung früherer Aussagen und bisher nicht erwähnten Themen. Angesprochen wurden das Fanverhalten, Alkoholkonsum und das Verhalten der Polizei. Die ersten beiden Autoren führten unabhängig eine zusammenfassende qualitative Inhaltsanalyse (Mayring, 2008) des transkribierten Gesprächs durch, um die Aussagen zu strukturieren und zu kategorisieren. Ergebnisse und Diskussion Verschiedene Kriterien zur Identifizierung einer KS wurden gefunden, beispielsweise „fehlende Distanz zwischen Fans und Polizei“, „Vermummung der Fans“, „Zusammenrücken der Fangruppe“ sowie „Aktionen ausserhalb der Fanrituale“. Diese und weitere Kategorien lassen sich vier Überkategorien zuordnen und damit strukturieren. Es gelang, durch die Methode der Fokusgruppe, relevante und beobachtbare Faktoren zu identifizieren, um kritische Situationen im Kontext der Fußballzuschauer auch dann zu erkennen, wenn es nicht zu Ausschreitungen kommt. Dies ist eine wichtige Voraussetzung, um die Dynamik der Gewalteskalation oder Mitigation im Feld untersuchen zu können. Literatur Bohnsack, R. (2007). Gruppendiskussion. In U. Flick, E. von Kardorff & I. Steinke (Hrsg.), Qualitative For-schung: Ein Handbuch (5. Auflage) (S. 369-384). Reinbek bei Hamburg: Rowohlt. Hylander, I., & Guvå, G. (2010). Misunderstanding of out-group behaviour: Different interpretations of the same crowd events among police officers and demonstrators. Nordic Psychology, 62, 25-47. Mayring, P. (2008).Qualitative Inhaltsanalyse: Grundlagen und Techniken (10. Auflage). Weinheim und Basel: Beltz.

ICOMF: Towards a Multi-cloud Ecosystem for Dynamic Resource Composition and Scaling

Modern cloud-based applications and infrastructures may include resources and services (components) from multiple cloud providers, are heterogeneous by nature and require adjustment, composition and integration. The specific application requirements can be met with difficulty by the current static predefined cloud integration architectures and models. In this paper, we propose the Intercloud Operations and Management Framework (ICOMF) as part of the more general Intercloud Architecture Framework (ICAF) that provides a basis for building and operating a dynamically manageable multi-provider cloud ecosystem. The proposed ICOMF enables dynamic resource composition and decomposition, with a main focus on translating business models and objectives to cloud services ensembles. Our model is user-centric and focuses on the specific application execution requirements, by leveraging incubating virtualization techniques. From a cloud provider perspective, the ecosystem provides more insight into how to best customize the offerings of virtualized resources.

SLA-driven predictive orchestration for distributed cloud-based mobile services

We describe a system for performing SLA-driven management and orchestration of distributed infrastructures composed of services supporting mobile computing use cases. In particular, we focus on a Follow-Me Cloud scenario in which we consider mobile users accessing cloud-enable services. We combine a SLA-driven approach to infrastructure optimization, with forecast-based performance degradation preventive actions and pattern detection for supporting mobile cloud infrastructure management. We present our system's information model and architecture including the algorithmic support and the proposed scenarios for system evaluation.

Mobile Cloud Networking: Mobile Network, Compute, and Storage as One Service On-Demand

The Future Communication Architecture for Mobile Cloud Services: Mobile Cloud Networking (MCN) is a EU FP7 Large-scale Integrating Project (IP) funded by the European Commission. MCN project was launched in November 2012 for the period of 36 month. In total top-tier 19 partners from industry and academia commit to jointly establish the vision of Mobile Cloud Networking, to develop a fully cloud-based mobile communication and application platform.