Tomotherapy archive structure and new software tool for loading and advanced analysis of data contained in it

AbstractAimThe main objective of the study was to analyze the structure of data contained in the archives exported from a tomotherapy treatment planning system. An additional aim was to create an application equipped with a user-friendly interface to enable automatic reading of files and data analysis, also using external algorithms. Analyses had to include image registration, dose deformation and summation.Materials and methodsFiles from the archive exported from the tomotherapy treatment planning system (TPS) were analyzed. Two programs were used to analyze the information contained in the archive files: XML Viewer by MindFusion Limited and HxD hex editor by Maël Hora. To create an application enabling loading and analyzing the data, Matlab by MathWorks, version R2009b, was used.ResultsArchive exported from the TPS is a directory with several files. It contains three types of data: .xml, .img and .sin. Tools available in Matlab offer great opportunities for analysis and transformation of loaded information. Proposed application automates the loading of necessary information and simplifies data handling. Furthermore, the application is equipped with a graphical user interface (GUI). The main application window contains buttons for opening the archives and analyzing the loaded data.ConclusionThe analysis of data contained in the archive exported from the tomotherapy treatment planning system allowed to determine the way and place of saving information of our interest, such as tomography images, structure sets and dose distributions. This enabled us to develop and optimize methods of loading and analyzing this information

Respiratory motion and its compensation possibilities in the modern external beam radiotherapy of lung cancer

The aim of this paper is to present a systematic review of the current characteristics and recent development of commercially available respiratory motion solutions and their compensation possibilities in the external beam radio­therapy treatment of lung cancer. The most commonly used X-ray and radiotherapeutic technologies are presented, as well as their division into pre-treatment methods and intra-treatment verification. The article discusses the most important technological achievements that allow radiation to be safely applied in the lung region and reports the potential advantages and limitations of each. Finally, it presents details concerning selected research trends and problems related to motion compensation

Synthesis and properties of aromatic 1,3-diketones and bis-(1,3-diketones) obtained from acetophenone and phtalic acids esters

Dibenzoylmethane and six aromatic 1,3-diketones containing a dibenzoylmethane moiety were synthesized from acetophenone and the appropriate ester in crossed-Claisen condensations. The synthesized diketones include derivatives containing carboxyl and ester groups; bis-(1,3-diketones) were also prepared. The absorption of UV radiation of the obtained compounds was investigated in various solvents, and their molar absorption coefficients were calculated. The ratio of tautomers and keto-enol equilibrium constants were calculated using 1H NMR techniques. Aromatic bis-(1,3-diketones) demonstrated strong hyperchromic effects. The keto-enol equilibrium of the investigated compounds is strongly shifted to the enol form, especially in non-polar solvents

Comparison of dose volume histograms for supine and prone position in patients irradiated for prostate cancer—A preliminary study

AbstractAimTo compare DVHs for OARs in two different positions – prone and supine – for prostate cancer patients irradiated with a Tomotherapy unit.BackgroundIn the era of dose escalation, the choice of optimal patient immobilization plays an essential role in radiotherapy of prostate cancer.Materials and methodsThe study included 24 patients who were allocated to 3 risk groups based on D’Amico criteria; 12 patients represented a low or intermediate and 12 a high risk group.For each patient two treatment plans were performed: one in the supine and one in the prone position. PTV included the prostate, seminal vesicles and lymph nodes for the high risk group and the prostate and seminal vesicles for the intermediate or low risk groups. DVHs for the two positions were compared according to parameters: Dmean, D70, D50 and D20 for the bladder and rectum and Dmean, D10 for the intestine. The position accuracy was verified using daily MVCT.ResultsProne position was associated with lower doses in OARs, especially in the rectum. Despite the fact that in the entire group the differences between tested parameters were not large, the Dmean and D10 for the intestine were statistically significant. In the case of irradiation only to the prostate and seminal vesicles, the prone position allowed for substantial reduction of all tested DVH parameters in the bladder and rectum, except D20 for bladder. Moreover, the Dmean and D50 parameter differences for the bladder were statistically significant.No significant differences between positions reproducibility were demonstrated.ConclusionIn patients irradiated to prostate and seminal vesicles, the prone position may support sparing of the rectum and bladder.The reproducibility of position arrangement in both positions is comparable

Silver nanoparticles augment releasing of pyrogenic factors by blood cells stimulated with LPS

Silver nanoparticles (AgNPs) have cytotoxic properties via generation of reactive oxygen species which are involved in the generalized sickness behavior of the host including fever and lethargy among others. The aim of the present study was to investigate the impact of AgNPs on the ability of rat peripheral blood mononuclear cells (PBMCs) to release fever mediating factors after stimulation with lipopolysaccharide (LPS). Body temperature and motor activity of the Wistar rats were measured by biotelemetry system. Rat PBMCs were stimulated with LPS and after that, the cells were washed and incubated alone or with AgNPs. The final supernatants were injected intraperitoneally. The levels of endogenous pyrogens such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) released from the PBMCs into the final supernatants were also estimated. The results indicated that injection of the supernatants from the cells stimulated with LPS induced fever and inhibited motor activity. These effects were potentiated by the presence of AgNPs during the final incubation. The presence of the AgNPs also resulted in significant increases in levels of endogenous pyrogens. The augmentation of fever in the rats by the AgNPs treatment of the cultures seemed to be primarily associated with the changes in interleukin-1β levels

Importance of Atomic Composition and Moisture Content of Cement based Composites in Neutron Radiation Shielding

AbstractMonte Carlo computer simulations confirmed that an increase in density has a minor effect on the weakening of neutron transport and, therefore, the optimum composition of a shielding concrete against gamma radiation is different than the one against neutron radiation. Neutron radiation shielding is a two-step process: slowing down of fast neutrons and absorption of thermal ones. Both result from the atomic composition of the barrier but their dependence on specified atomic compositions and moisture content is different. The aim of the presented research is to develop a high density concrete the composition of which would also assure good efficiency of neutron shielding. Neutron transport through standard cement mortar, PCC mortar, normal-weight concrete and magnetite heavy-weight concrete has been analyzed in the paper. The goal in research was to find an influence of the cement type, polymer addition, density and moisture content on the shielding properties against neutron. The research based on convergent results of MC computer simulations and real experiments confirmed the influence of the cement type on fast neutron attenuation. It was also found that each 1% of moisture content makes 10% increase of fast neutron thermalization effectiveness, what is a little less than it was estimated for cement based mortars. It was also proved that heavy-weight concrete is not proper solution for shielding against fast neutrons, but its efficiency is visible in the case of thermal neutrons absorption, probably due to increase of Fe content at the expense of Si and O in the atomic composition as well as water retained by magnetite aggregate