Genomic Analysis of Advanced Breast Cancer Using Two Types of Next Generation Sequencing

The aim of this study is to characterize the genomic alterations of advance stage breast cancer using next generation sequencing (NGS) to identify pathways that may be commonly altered in advance stage breast cancer

Approximation algorithms and hardness results for the joint replenishment Problepm with constant demands

19th Annual European Symposium, Saarbrücken, Germany, September 5-9, 2011. ProceedingsIn the Joint Replenishment Problem (JRP), the goal is to coordinate the replenishments of a collection of goods over time so that continuous demands are satisfied with minimum overall ordering and holding costs. We consider the case when demand rates are constant. Our main contribution is the first hardness result for any variant of JRP with constant demands. When replenishments per commodity are required to be periodic and the time horizon is infinite (which corresponds to the so-called general integer model with correction factor), we show that finding an optimal replenishment policy is at least as hard as integer factorization. This result provides the first theoretical evidence that the JRP with constant demands may have no polynomial-time algorithm and that relaxations and heuristics are called for. We then show that a simple modification of an algorithm by Wildeman et al. (1997) for the JRP gives a fully polynomial-time approximation scheme for the general integer model (without correction factor). We also extend their algorithm to the finite horizon case, achieving an approximation guarantee asymptotically equal to √9/8

Real-Time Treatment Planning Optimisation for Brachytherapy

In this paper, we present an integrated system for real-time dose distribution calculation and treatment planning optimisation for brachytherapy of prostate cancer, with a special emphasis on the visual integration of the dosimetry and target images obtained from the open magnetic resonance system. This system involves a fast method to calculate dose distributions of multiple concurrent radioactive sources, based on the combination of elements from a database of pre-calculated dose distribution maps for single sources, combined linearly to provide the final dose distribution map. Simulated annealing, in conjunction with the inverse planning method, is used to determine the source dwell times at pre-selected locations in order to optimally irradiate thetumour while preserving the surrounding healthy tissues. This algorithm, implemented in FORTRAN, is integrated into a computer-assisted treatment planning tool, written in JAVA, using the runtime class and RMI API of Java. The whole system is now under clinical testing at the Geneva University Hospital

Characterisation of MCP-7s- material for use as a beta extremity dosemeter

LiF:Mg,Cu,P phosphors (commercially designated as MCP-N) are very sensitive thermoluminescent detectors and are considered by many laboratories to hold great promise for low level radiation monitoring. It is their high efficiency relative to TLDs based on LiF:Mg,Ti which make MCP-N particularly attractive for low dose measurements. The currently investigated detector material made of LiF:Mg,Cu,P bears the code name MCP-7s and has a very thin active layer and consequently an improved response to low energy beta radiation. Detailed studies have been carried out to characterise MCP-7s detectors in terms of glow curve, beta and gamma response, reusability, batch homogeneity and fading. Based on the positive outcome of these investigations, the dosimetry service at PSI plans to replace the TL material LiF:Mg,Ti presently used for extremity dosimetry with MCP-7