107 research outputs found
Nephron-sparing management of upper tract urothelial carcinoma
Urothelial carcinoma of the upper urinary tract is uncommon and presents unique challenges for diagnosis and management. Nephroureterectomy has been the preferred management option, but it is associated with significant morbidity. Nephron-sparing treatments are a valuable alternative and provide similar efficacy in select cases. A PubMed literature review was performed in English language publications using the following search terms: urothelial carcinoma, upper tract, nephron-sparing, intraluminal and systemic therapy. Contemporary papers published within the last 10 years were primarily included. Where encountered, systematic reviews and meta-analyses were given priority, as were randomized controlled trials for newer treatments. Core guidelines were referenced and citations reviewed for inclusion. A summary of epidemiological data, clinical diagnosis, staging, and treatments focusing on nephron-sparing approaches to upper tract urothelial carcinoma (UTUC) are outlined. Nephron-sparing management strategies are viable options to consider in patients with favorable features of UTUC. Adjunctive therapies are being investigated but the data remains mixed. Protocol variability and dosage differences limit statistical interpretation. New mechanisms to improve treatment dwell times in the upper tracts are being designed with promising preliminary results. Studies investigating systemic therapies are ongoing but implications for nephron-sparing management are uncertain. Nephron-sparing management is an acceptable treatment modality best suited for favorable disease. More work is needed to determine if intraluminal and/or systemic therapies can further optimize treatment outcomes beyond resection alone
PEBSI - A Monte Carlo simulator for bremsstrahlung arising from electrons colliding with thin solid-state targets
We present a Monte Carlo code dedicated to the simulation of bremsstrahlung
arising in collisions of polarized electrons with thin target foils. The
program consists of an electron transport algorithm taking into account elastic
electron-nucleus scattering and inelastic collisions with target electrons as
well as a treatment of polarized-electron bremsstrahlung emission. Good
agreement is found between the predictions of the electron transport code and
data stemming from other simulation programs and experiments. In addition, we
present first results from the bremsstrahlung simulation which indicate a
significant decrease in the degree of linear polarization of bremsstrahlung
even for the thinnest gold targets considered
Ionisation Models for Nano-Scale Simulation
Two theory-driven models of electron ionization cross sections, the
Binary-Encounter-Bethe model and the Deutsch-M\"ark model, have been design and
implemented; they are intended to extend the simulation capabilities of the
Geant4 toolkit. The resulting values, along with the cross sections included in
the EEDL data library, have been compared to an extensive set of experimental
data, covering more than 50 elements over the whole periodic table.Comment: 4 pages, to appear in proceedings of the Nuclear Science Symposium
and Medical Imaging Conference 2010, Knoxvill
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