Lukarski, Dushko
Preferred name
Lukarski, Dushko
Official Name
Lukarski, Dushko
Translated Name
Lukarski, Dusko
Main Affiliation
Email
dushko.lukarski@medf.ukim.edu.mk
25 results
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Item type:Publication, Helical tomotherapy versus conventional intensity-modulated radiation therapy for primary chemoradiation in cervical cancer patients: an intraindividual comparison(Elsevier BV, 2011-10-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Concurrent radiochemotherapy in advanced hypopharyngeal cancer(2010-05-18); ; Concurrent platinum-based radiochemotherapy has been recommended as a standard of care in patients with locally advanced squamous cell head and neck carcinomas. Unfortunately, there is a lack of level one evidence on best treatment approach for advanced hypopharyngeal cancer. This report aims to summarize the results of our study on concurrent radiochemotherapy in patients with advanced hypopharyngeal cancer. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Radiosensitizing properties of dual-functionalized carbon nanostructures loaded with temozolomide(Beilstein Institut, 2025-02-19); ; ; In the present study, temozolomide (TMZ), a drug used for the treatment of anaplastic astrocytoma and glioblastoma multiforme (GBM), was incorporated into multiwalled carbon nanotubes (MWCNTs) and a MWCNTs–graphene (MWCNTs-G) hybrid compound, covalently functionalized with polyethylene glycol (PEG) 6000 and folic acid (FA), with an aim to prepare nanocarriers with the potential to prolong the drug circulation time, cross the blood–brain–tumor barrier (BBTB), and provide targeted and controlled drug release in the brain tumor cells. Cytotoxicity and effects on cell membrane integrity of the blank and TMZ-loaded dual-functionalized carbon nanostructures (CNs) were evaluated in vitro on a GBM cell line (U87MG), as well as their radiosensitizing properties after exposure of the pre-treated GBM cells to gamma radiation with a standard clinical dose for patients with GBM. All prepared formulations underwent biopharmaceutical and physicochemical characterization, including the formulations exposed to irradiation under the same conditions. For physicochemical characterization of the formulations, different techniques were used by which successful functionalization of the CNs and TMZ loading were confirmed and visualized; no significant changes in the structure of the CNs and TMZ after irradiation were observed. With single and dual functionalization, formulations with relatively high TMZ loading efficiency and drug content were prepared. They exhibited homogeneous particle size distributions and mean particle sizes and surface charges suitable for crossing the BBTB and targeting brain cancer cells. A biphasic drug release profile was observed for all functionalized TMZ-loaded formulations in simulated in vivo conditions, with a sustained release pointing to the potential for controlled release of TMZ in brain tumor cells. The formulations of the hybrid CN MWCNTs-G compared to the corresponding MWCNTs were characterized by a similar or slightly higher TMZ content, larger particle size, similar surface charge, and slightly faster TMZ release, which can be attributed to the planar structure of graphene that promotes TMZ binding to the surface on a larger scale. For the irradiated CNs, lower values for particle size, more positive values for surface charge, and accelerated TMZ release were observed, which could be explained by changes in the physicochemical characteristics of the prepared formulations upon irradiation. Significant concentration-dependent toxicity was observed for blank dual-functionalized CNs, being higher for MWCNTs-G-PEG6000-FA compared to MWCNTs-PEG6000-FA at the same formulation concentrations. With incorporation of TMZ into the functionalized CNs, the cell viability additionally decreased, maintaining the trend for higher cytotoxicity of the hybrid CN. Additional decrease in the viability of cells was observed when GBM cells pre-treated with the corresponding CNs were exposed to irradiation, which could be ascribed to changes in size, surface charge, and release kinetics of TMZ and to irradiation-induced changes in the microenvironment and cell membranes that promote uptake of a larger volume of carriers in the GBM cells. The higher cytotoxicity observed in the hybrid carrier formulations could most likely be attributed to the length of the hybrid carrier and the higher proportion of planar surface, which promotes more intense contact with the cells and rupture of cell membranes. Overall, the findings demonstrate the radiosensitizing properties of not only TMZ but also of CNs and point to a clinical benefit from combined treatment with carbon nanocarriers of TMZ and radiotherapy in GBM. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, DETECTION AND DETERMINATION OF RADIOACTIVE SURFACE CONTAMINATION WITH THE USE OF GAMMA CAMERA(University Ss. Cyril and Methodius in Skopje, 2025); ; ; ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Time Window Determination for Inference of Time-Varying Dynamics: Application to Cardiorespiratory Interaction(Frontiers Media SA, 2020); ; ; Interacting dynamical systems abound in nature, with examples ranging from biology and population dynamics, through physics and chemistry, to communications and climate. Often their states, parameters and functions are time-varying, because such systems interact with other systems and the environment, exchanging information and matter. A common problem when analysing time-series data from dynamical systems is how to determine the length of the time window for the analysis. When one needs to follow the time-variability of the dynamics, or the dynamical parameters and functions, the time window needs to be resolved first. We tackled this problem by introducing a method for adaptive determination of the time window for interacting oscillators, as modeled and scaled for the cardiorespiratory interaction. By investigating a system of coupled phase oscillators and utilizing the Dynamical Bayesian Inference method, we propose a procedure to determine the time window and the propagation parameter of the covariance matrix. The optimal values are determined so that the inferred parameters follow the dynamics of the actual ones and at the same time the error of the inference represented by the covariance matrix is minimal. The effectiveness of the methodology is presented on a system of coupled limit-cycle oscillators and on the cardiorespiratory interaction. Three cases of cardiorespiratory interaction were considered-measurement with spontaneous free breathing, one with periodic sine breathing and one with a-periodic time-varying breathing. The results showed that the cardiorespiratory coupling strength and similarity of form of coupling functions have greater values for slower breathing, and this variability follows continuously the change of the breathing frequency. The method can be applied effectively to other time-varying oscillatory interactions and carries important implications for analysis of general dynamical systems. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Time Window Determination for Inference of Time-Varying Dynamics: Application to Cardiorespiratory Interaction(Frontiers Media SA, 2020); ; ; Stankovski, TomislavInteracting dynamical systems abound in nature, with examples ranging from biology and population dynamics, through physics and chemistry, to communications and climate. Often their states, parameters and functions are time-varying, because such systems interact with other systems and the environment, exchanging information and matter. A common problem when analysing time-series data from dynamical systems is how to determine the length of the time window for the analysis. When one needs to follow the time-variability of the dynamics, or the dynamical parameters and functions, the time window needs to be resolved first. We tackled this problem by introducing a method for adaptive determination of the time window for interacting oscillators, as modeled and scaled for the cardiorespiratory interaction. By investigating a system of coupled phase oscillators and utilizing the Dynamical Bayesian Inference method, we propose a procedure to determine the time window and the propagation parameter of the covariance matrix. The optimal values are determined so that the inferred parameters follow the dynamics of the actual ones and at the same time the error of the inference represented by the covariance matrix is minimal. The effectiveness of the methodology is presented on a system of coupled limit-cycle oscillators and on the cardiorespiratory interaction. Three cases of cardiorespiratory interaction were considered-measurement with spontaneous free breathing, one with periodic sine breathing and one with a-periodic time-varying breathing. The results showed that the cardiorespiratory coupling strength and similarity of form of coupling functions have greater values for slower breathing, and this variability follows continuously the change of the breathing frequency. The method can be applied effectively to other time-varying oscillatory interactions and carries important implications for analysis of general dynamical systems. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Time-variability of cardiorespiratory interactions(IEEE, 2020-07); ; ; The cardiorespiratory interactions are important physiological phenomenon, but often their time-variability makes the analysis difficult. Here we present the results of applying a procedure for optimal determination of the time window and method parameters, based on dynamical Bayesian inference. This was applied on cardiorespiratory measurements of one subject following two different respiration patterns spontaneous free breathing and aperiodic breathing. By investigating the time-variability of cardiorespiratory coupling functions we demonstrate the effectiveness of the method. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Transmission Comparison for Two Different Electron Block Materials(Association for Medical Physics and Biomedical Engineering, 2010-11-06); The purpose of this work is to compare electron beam transmission, under two different block materials. The first one, cerrobend, consists of 10% cadmium and the second one is cadmium free. Percentage depth doses for open and block fields for all electron energies are measured. Measurements were performed with a plan-parallel ionization chamber over a range of depth from water surface to a depth of 160mm. The fields were defined using a 15x15 electron applicator mounted on linear accelerator. Depth dose curves beyond two alloys are matched and compared. Regarding the results, the percentage depth doses behind blocks correspond very well. The difference between the two alloy curves does not exceed 0.12%. The conclusion of the article is that a coincidence in transmission is acceptable. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Treatment Planning System Commissioning of the Eclipse PBC Dose Calculation Algorithm for the Varian Clinac iX S/N 5052(Association for Medical Physics and Biomedical Engineering, 2013-10-19); Nikolovski, DraganThe commissioning of the Treatment Planning System (TPS) is an important part of the commissioning of a new linear accelerator (linac). In this work, we evaluated the performance of the Pencil Beam Convolution (PBC) algorithm configured for the new Varian Clinac iX (S/N 5052) at the University Clinic of Radiotherapy and Oncology in Skopje. The evaluation was performed in two stages. In the first stage, we used a workspace of the TPS itself, called “Beam Analysis”, in which the system itself calculates the depth dose and profile curves for a water phantom and compares them with those measured during the commissioning of the accelerator. In the second stage, we created, calculated and irradiated 9 test plans on a polystyrene phantom “OPERA” and measured the dose in a point with a system for absolute dosimetry and then compared the measurements with the calculations. In both stages, the results of the comparison were below 3%, in most clinically relevant cases below 2%, which indicates that the PBC algorithm can safely be commissioned for clinical use. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Determining the Efficiency of a Commercial Belly Board Device in Reducing Small Bowel Volume in Rectal Cancer Patients(Association for Medical Physics and Biomedical Engineering, 2010-11-06);
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