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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

PRONTOX – proton therapy to reduce acute normal tissue toxicity in locally advanced non-small-cell lung carcinomas (NSCLC): study protocol for a randomised controlled trial

Zschaeck, Sebastian, Simon, Monique, Löck, Steffen, Troost, Esther G. C., Stützer, Kristin, Wohlfahrt, Patrick, Appold, Steffen, Makocki, Sebastian, Bütof, Rebecca, Richter, Christian, Baumann, Michael, Krause, Mechthild 17 March 2017 (has links) (PDF)
Background Primary radiochemotherapy with photons is the standard treatment for locally advanced-stage non-small cell lung cancer (NSCLC) patients. Acute radiation-induced side effects such as oesophagitis and radiation pneumonitis limit patients’ quality of life, and the latter can be potentially life-threatening. Due to its distinct physical characteristics, proton therapy enables better sparing of normal tissues, which is supposed to translate into a reduction of radiation-induced side effects. Methods/design This is a single-centre, prospective, randomised controlled, phase II clinical trial to compare photon to proton radiotherapy up to 66 Gy (RBE) with concomitant standard chemotherapy in patients with locally advanced-stage NSCLC. Patients will be allocated in a 1:1 ratio to photon or proton therapy, and treatment will be delivered slightly accelerated with six fractions of 2 Gy (RBE) per week. Discussion The overall aim of the study is to show a decrease of early and intermediate radiation-induced toxicity using proton therapy. For the primary endpoint of the study we postulate a decrease of radiation-induced side effects (oesophagitis and pneumonitis grade II or higher) from 39 to 12%. Secondary endpoints are locoregional and distant failure, overall survival and late side effects. Trial registration Registered at ClinicalTrials.gov with Identifier NCT02731001 on 1 April 2016.
22

Suppression von paroxysmalem Vorhofflimmern durch bifokale rechtsatriale Schrittmacherstimulation

Gerhardt, Lars 19 December 2005 (has links)
Vorhofflimmern ist die häufigste behandlungsbedürftige Herzrhythmusstörung. Die Erhöhung des Schlaganfallrisikos, die Einschränkung der Herzleistung und nicht zuletzt ein Verlust an Lebensqualität sind bedeutsame Folgen dieser Erkrankung. Bisherige pharmakologische Therapieansätze sind insbesondere beim paroxysmalem Vorhofflimmern nur von unzureichender Wirkung, so dass in letzter Zeit nicht-pharmakologische Therapieoptionen untersucht werden. Elektrophysiologische und klinische Untersuchungen legen nahe, dass bifokale rechtsatriale Schrittmacherstimulation die Rezidivhäufigkeit von paroxysmalem Vorhofflimmern senken kann. In der DUSTI-Studie (DUal-site STImulation for prevention of paroxysmal atrial fibrillation) wurde untersucht, ob bifokale atriale Überstimulation die Rezidivhäufigkeit gegenüber unifokaler Überstimulation und lediglich antibradykarder Stimulation senken kann. Hierzu wurden 19 Patienten (61 ± 12 Jahre, 13 männlich) mit paroxysmalem Vorhofflimmern und einer Indikation zur Schrittmacherimplantation in eine prospektive, einfach-blinde, randomisierte Cross-over-Studie eingeschlossen. Ein herkömmlicher Zwei-Kammer-Schrittmacher, eine ventrikuläre Sonde und zwei über einen Y-Konnektor verbundene rechtsatriale Sonden, eine septal, die andere lateral wurden implantiert. Alle Patienten wurden zunächst 12 Wochen durch Programmierung einer Interventionsfrequenz von 50/min möglichst wenig atrial stimuliert. Danach wurden alle Patienten möglichst immer atrial stimuliert (Überstimulation mit 10/min über der Eigenfrequenz), in zufälliger Reihenfolge 12 Wochen bifokal (septal und lateral) und 12 Wochen unifokal (septal oder lateral). Unter bifokaler Stimulation war die Vorhofflimmerlast ebenso groß wie unter unifokaler Stimulation (6,20% ± 9,91% vs. 6,15% ± 11,09%, Intention-to-treat-Analyse) In den Überstimulationsphasen zeigte sich ein Trend zur Abnahme der Vorhofflimmerlast gegenüber der Phase mit geringen atrialen Stimulationsraten (6,15% ± 10,32% vs. 8,84% ± 11,34%, p=0,09, Intention-to-treat-Analyse). Hinsichtlich der Anzahl der Vorhofflimmerepisoden, der Zeit bis zum Vorhofflimmerrezidiv und der Symptomatik fanden sich signifikante Unterschiede weder zwischen uni- und bifokaler Stimulation, noch zwischen Überstimulation und geringer atrialer Stimulation. Die verwendeten Methoden waren gut durchführbar und sicher. Die schrittmacherbasierte Vorhofflimmerdiagnostik erwies sich, vor allem durch die zusätzliche atriale Elektrode, als technisch kompliziert und teilweise fehlerbehaftet. In einem nicht selektierten Patientenkollektiv ist die bifokale rechtsatriale Schrittmacherstimulation zur Rezidivprophylaxe des paroxysmalen Vorhofflimmerns nicht besser geeignet als unifokale Stimulation. Der höhere Aufwand der Implantation einer zweiten atrialen Sonde scheint nicht gerechtfertigt. Andere Studien müssen zeigen, ob bestimmte Patienten-Subgruppen von der bifokalen rechtsatrialen Stimulation profitieren / Atrial fibrillation is the most common sustained cardiac arrhythmia. It substantially increases the risk of stroke, impairs cardiac output and may lower the quality of life. Because pharmacotherapeutic approaches often yield unsatisfactory results - especially with paroxysmal atrial fibrillation, various non-pharmacological therapies have been studied. Electrophysiological and clinical research suggests, that dual-site atrial stimulation may suppress paroxysms of atrial fibrillation. The DUSTI trial was designed to test the hypothesis that dual-site stimulation prevents atrial fibrillation better than single-site stimulation or support pacing. Nineteen patients (61 ± 12 years, 13 male) with paroxysmal atrial fibrillation and a standard indication for pacemaker implantation were included in a prospective, single-blinded, randomized cross-over-trial. A conventional dual-chamber pacemaker with one ventricular and two atrial leads was implanted. Atrial leads were placed at the atrial septum and at the right atrial wall, and connected via a Y-connector to the atrial port. For the first twelve weeks patients only received support pacing (at 50 bpm). Afterwards patients received continuous atrial pacing (at 10 bpm above the intrinsic heart rate), 12 weeks dual-site pacing (septal and lateral) and 12 weeks single-site pacing (septal or lateral) in random order. Atrial fibrillation burden was the same between dual-site pacing and single-site pacing (6.20% ± 9.91% vs. 6.15% ± 11.09%, intention-to-treat-analysis). A trend towards less atrial fibrillation with continuous pacing compared to support pacing was observed (6.15% ± 10.32% vs. 8.84% ± 11.34%, p=0.09, intention-to-treat-analysis). There was no significant difference in number of atrial fibrillation episodes, time to recurrence and symptoms, neither between dual- and single-site pacing, nor between continuous and support pacing. Dual-site pacing proved to be feasible and safe. The detection of atrial fibrillation by the pacemaker''s diagnostic algorithms was, however, troubled by the additional atrial lead. Dual-site pacing offers no further advantage to single-site pacing for prevention of atrial fibrillation recurrences in unselected patients. The implantation of an additional atrial lead in patients with paroxysmal atrial fibrillation, requiring a pacemaker, seems to be not justified. Future trials will investigate whether certain subgroups of patients will benefit from dual-site atrial pacing.
23

Ein semiparametrisches Verfahren zur Planung und Auswertung von Nichtunterlegenheitsstudien im Cox-Modell / A semiparametric method for planning and evaluating non-inferiority trials in the Cox model framework

Kombrink, Karola 10 November 2011 (has links)
No description available.
24

PRONTOX – proton therapy to reduce acute normal tissue toxicity in locally advanced non-small-cell lung carcinomas (NSCLC): study protocol for a randomised controlled trial

Zschaeck, Sebastian, Simon, Monique, Löck, Steffen, Troost, Esther G. C., Stützer, Kristin, Wohlfahrt, Patrick, Appold, Steffen, Makocki, Sebastian, Bütof, Rebecca, Richter, Christian, Baumann, Michael, Krause, Mechthild 17 March 2017 (has links)
Background Primary radiochemotherapy with photons is the standard treatment for locally advanced-stage non-small cell lung cancer (NSCLC) patients. Acute radiation-induced side effects such as oesophagitis and radiation pneumonitis limit patients’ quality of life, and the latter can be potentially life-threatening. Due to its distinct physical characteristics, proton therapy enables better sparing of normal tissues, which is supposed to translate into a reduction of radiation-induced side effects. Methods/design This is a single-centre, prospective, randomised controlled, phase II clinical trial to compare photon to proton radiotherapy up to 66 Gy (RBE) with concomitant standard chemotherapy in patients with locally advanced-stage NSCLC. Patients will be allocated in a 1:1 ratio to photon or proton therapy, and treatment will be delivered slightly accelerated with six fractions of 2 Gy (RBE) per week. Discussion The overall aim of the study is to show a decrease of early and intermediate radiation-induced toxicity using proton therapy. For the primary endpoint of the study we postulate a decrease of radiation-induced side effects (oesophagitis and pneumonitis grade II or higher) from 39 to 12%. Secondary endpoints are locoregional and distant failure, overall survival and late side effects. Trial registration Registered at ClinicalTrials.gov with Identifier NCT02731001 on 1 April 2016.

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