The objective of this paper is to present our experience in the commissioning and quality assurance (QA) for intensity modulated radiotherapy (IMRT) using dynamic multileaf collimator (dMLC), sliding window technique. Using Varian equipment solution, the connectivity and operation between all IMRT chain components was checked. Then the following test were done: stability of leaf positioning and...

PURPOSE To study the impacts of multileaf collimators (MLC) width [standard MLC width of 10 mm (sMLC) and micro-MLC width of 4 mm (mMLC)] in the intensity-modulated radiotherapy (IMRT) planning for the upper thoracic esophageal cancer (UTEC). METHODS AND MATERIALS 10 patients with UTEC were retrospectively planned with the sMLC and the mMLC. The monitor unites (MUs) and dose volume histogram-...

BACKGROUND AND PURPOSE Solid-state detectors such as diodes and diamonds are useful radiation detectors, particularly for small field measurements, such as in stereotactic dosimetry or in the small sub-field measurements required for intensity modulated radiotherapy (IMRT) . In all small field measurements, positioning of the detector is critical. Generally it is assumed that the center of the ...

BACKGROUND A new-generation low-energy linear accelerator (UNIQUE) was introduced in the clinical arena during 2009 by Varian Medical Systems. The world's first UNIQUE was installed at Oncology Institute of Southern Switzerland and put into clinical operation in June 2010. The aim of the present contribution was to report experience about its commissioning and first year results from clinical o...

Some mechanical problems involve inequality kinematic constraint. This study deals with an original approach to handle those difficult problems. The main issue is the treatment of the variational inequalities due to the fact that the constrained area is a priori unknown. The method, introduced here, is to find the exact constrained area iteratively starting from an intial trial one. Thanks to n...

Singleton Arc-Consistency (SAC) [7] is a simple and strong level of consistency but is costly to enforce. To date, research has focused on improving the performance of algorithms that achieve SAC, and comparing algorithms as a preprocessing step before actually solving a problem. Here, we show for the first time how a basic SAC algorithm can be readily incorporated into an open source constrain...

We optimized and tested a postbioprocessing step with a single-culture archaeon to upgrade biogas (i.e., increase methane content) from anaerobic digesters via conversion of CO(2) into CH(4) by feeding H(2) gas. We optimized a culture of the thermophilic methanogen Methanothermobacter thermautotrophicus using: (1) a synthetic H(2)/CO(2) mixture; (2) the same mixture with pressurization; (3) a s...

In this study, the organic loading rate (OLR) of a high-solids anaerobic digestion (HSAD) system was increased from 3.4 to 5.0 gVS L(-1) day(-1) and reactor stability, performance and microbial community structure were determined. Laboratory simulations (3.5 L) of the full-scale process (500 dry ton year(-1)) were conducted using continuously stirred-tank mesophilic reactors. OLRs of 3.4 gVS L(...

We compare the three most commonly used scanning probe techniques to obtain a reliable value of the work function in graphene domains of different thickness. The surface potential (SP) of graphene is directly measured in Hall bar geometry via a combination of electrical functional microscopy and spectroscopy techniques, which enables calibrated work function measurements of graphene domains in ...