A5070920536- Advanced Radiotherapy Techniques
- Lipid Membrane Structure and Behavior
- Radiation Dose and Imaging
- Radiomics and Machine Learning in Medical Imaging
- Medical Imaging Techniques and Applications
- Radiation Therapy and Dosimetry
- Lung Cancer Diagnosis and Treatment
- Head and Neck Cancer Studies
- Spectroscopy and Quantum Chemical Studies
- Nanopore and Nanochannel Transport Studies
- Advanced X-ray and CT Imaging
- Microfluidic and Bio-sensing Technologies
- Photoreceptor and optogenetics research
- Erythrocyte Function and Pathophysiology
- Supramolecular Self-Assembly in Materials
- RNA Interference and Gene Delivery
- Esophageal Cancer Research and Treatment
- Surfactants and Colloidal Systems
- Radiation Effects in Electronics
- Mechanical and Thermal Properties Analysis
- Material Properties and Applications
- Structural Engineering and Materials Analysis
- Medical Imaging and Analysis
- Spectroscopy Techniques in Biomedical and Chemical Research
- Art, Technology, and Culture
Institute of Oncology Ljubljana
2013-2025
University of Ljubljana
1999-2013
For the cancer in head and neck (HaN), radiotherapy (RT) represents an important treatment modality. Segmentation of organs-at-risk (OARs) is starting point RT planning, however, existing approaches are focused on either computed tomography (CT) or magnetic resonance (MR) images, while multimodal segmentation has not been thoroughly explored yet. We present a dataset CT MR images same patients with curated reference HaN OAR segmentations for objective evaluation methods.The cohort consists...
To promote the development of auto-segmentation methods for head and neck (HaN) radiation treatment (RT) planning that exploit information computed tomography (CT) magnetic resonance (MR) imaging modalities, we organized HaN-Seg: The Head Neck Organ-at-Risk CT MR Segmentation Challenge. challenge task was to automatically segment 30 organs-at-risk (OARs) HaN region in 14 withheld test cases given availability 42 publicly available training cases. Each case consisted one contrast-enhanced...
Purpose: Different multichannel methods for film dosimetry have been proposed in the literature. Two of them are weighted mean method and put forth by Micke et al. ["Multichannel with nonuniformity correction," Med. Phys. 38, – (2011)] Mayer ["Enhanced procedures assessment EBT2 radiochromic film," 39, 2147–2155 (2012)]. The purpose this work was to compare their results develop a generalized channel-independent perturbations framework which both enter as special cases. Methods: Four models...
Abstract Background Accurate and consistent contouring of organs‐at‐risk (OARs) from medical images is a key step radiotherapy (RT) cancer treatment planning. Most approaches rely on computed tomography (CT) images, but the integration complementary magnetic resonance (MR) modality highly recommended, especially perspective OAR contouring, synthetic CT MR image generation for MR‐only RT, MR‐guided RT. Although has been recognized as valuable OARs in head neck (HaN) region, accuracy...
Background/Objectives: The aim of the study was to evaluate interobserver variability in determination primary tumor for radiotherapy treatment planning esophageal squamous cell carcinoma (ESCC). Methods: Sixteen patients with locally advanced ESCC were included analysis. In all positron emission tomography computed (PETC/CT) and magnetic resonance (MR) scans performed. Five experienced radiation oncologists delineated based on CT alone, MR PET/CT, fused PET/CT MR. Mean volumes calculated...
It is experimentally observed that adding a dimeric cationic amphiphile to the erythrocyte suspension results in release of stable tubular microexovesicles from membrane. Theoretical description starts single-inclusion energy, which takes into account anisotropic shape amphiphile. shown explicitly microexovesicle extremal functional yielding maximum average curvature deviator. derived for intrinsic shapes membrane inclusions created by intercalated amphiphiles deviator coincides with minimum...
Partitioning of fatty acids into phospholipid membranes is studied on giant unilamellar vesicles (GUVs) utilizing phase-contrast microscopy. With use a micropipet, an individual GUV transferred from vesicle suspension in mixed glucose/sucrose solution isomolar glycerol with small amount oleic acid added. Oleic molecules intercalate the membrane and thus increase area, while permeates interior via osmotic inflation causes volume. The conditions are chosen at which swells as sphere. At...
An external electric field deforms flaccid phospholipid vesicles into spheroidal bodies, with the rotational axis aligned its direction. Deformation is frequency dependent: in low-frequency range (∼1 kHz), deformation typically prolate, while increasing to 10 kHz changes oblate. We attempt explain this behaviour a theoretical model, based on minimization of total free energy vesicle. The terms taken account include membrane bending and field. latter calculated from via Maxwell stress tensor,...
As solute molecules permeate into a vesicle due to concentration difference across its membrane, the swells through osmosis. The swelling can be divided two stages: (a) an "ironing" stage, where volume-to-area ratio of increases without significant change in area; (b) stretching grows while remaining essentially spherical, until it ruptures. We show that crossover between these stages represented as broadened continuous phase transition. Consequently, curves for different vesicles and...
A technique for determining the permeability of a phospholipid membrane on single giant unilamellar vesicle (GUV) is described, which complements existing methods utilizing either planar black lipid or sub-micrometre-sized liposomes. GUV transferred using micropipette from solution nonpermeable solute into an iso-osmolar with higher permeability. Osmotical swelling monitored CCD camera mounted phase contrast microscope, and sequence images obtained. On each image, points contour are...
Abstract Background The aim of our study was to assess the inter-observer variability in delineation gross tumour volume (GTV) oesophageal cancer on magnetic resonance (MR) comparison computed tomography (CT) and positron emission CT (PET/CT). Patients methods Twenty-three consecutive patients with treated chemo-radiotherapy were enrolled. All had PET/CT MR imaging treatment position. Five observers independently delineated GTV alone, co-registered MR, alone PET/CT. Volumes measured per...
Lung cancer patients are often in poor physical condition, and a shorter treatment time would reduce their discomfort. Dynamic conformal arc therapy (DCAT) offers than conventional 3D radiotherapy (3D CRT) is usually available even departments without inverse planning possibilities. We examined its suitability as modality for lung patients.On cohort of 35 patients, relevant dosimetric parameters were compared respective DCAT CRT plans. Radiochromic film dosimetry an anthropomorphic phantom...
Quality control of cone-beam computed tomography (CBCT) systems is an essential part quality assurance to periodically check that requirements are met, reduce uncertainties and errors ...
Two methods of data analysis are compared: spreadsheet software and a statistics suite. Their use is compared analysing collected in three selected experiments taken from an introductory physics laboratory, which include linear dependence, nonlinear dependence histogram. The merits each method compared.
Background The aim of the study was to (a) compare accuracy two different immobilization strategies for patients with head and neck tumors, (b) set-up errors on treatment units portal imaging systems. Patients methods Variations in position isocenter (IC) relative reference point determined computed tomography simulator were measured a vertical (anterior-posterior), longitudinal (superior-inferior), lateral (medial-lateral) direction 120 cancer irradiated curative intent. Depending unit...
Background and purposeRadiation-induced damage to the hippocampi can cause cognitive decline. International recommendations for nasopharyngeal cancer (NPC) radiotherapy (RT) lack specific guidelines protecting hippocampi. Our study evaluates if hippocampi-sparing (HS) RT in NPC ensures target coverage meets recommended dose limits other at-risk organs.Materials methodsIn a systematic literature review, we compared hippocampal D40% conventional HS plans. In an silico dosimetric study, HS-VMAT...