Track topics on Twitter Track topics that are important to you
Fiducial markers are nowadays a common tool for patient positioning verification before radiotherapy treatment. These markers should be visible on X-ray projection imaging, produce low streak artifacts on CTs and induce small dose perturbations due to edge-scattering effects during the ion-beam therapy treatment. In this study, the latter effect was investigated and the perturbations created by the markers were evaluated with a new measurement method using a tracker system composed of six CMOS pixel sensors. The present method enables the determination of the particle trajectory before and after the target. The experiments have been conducted at the Marburg Ion Therapy Center with carbon ion beams and the measurement concept was validated by comparison with radiochromic films. This work shows that the new method is very efficient and precise to measure the perturbations due to fiducial markers with a tracker system. Three dimensional fluence distributions of all particle trajectories were reconstructed and the maximum cold spots due to the markers and their position along the beam axis were quantified. In this study, four small commercial markers with different geometries and materials (gold or carbon-coated ZrO) were evaluated. The gold markers showed stronger perturbations than the lower density ones. However, it is important to consider that low density and low atomic number fiducial markers are not always visible on X-ray projections.
This article was published in the following journal.
Name: Physics in medicine and biology
Our observational study aimed to verify the safety of our original titanium fiducial markers in gynecological cancer by using a simple insertion method. We prospectively evaluated the safety in patien...
To evaluate the feasibility of fiducial markers as a surrogate for GTV position in image-guided radiotherapy of rectal cancer.
Recently, the optical properties of silicon (Si) submicrometer spherical particles have been investigated to understand the dielectric nano-photonic function. Herein, we fabricated Si submicrometer sp...
To quantitatively evaluate and compare the image recognition performance of multiple fiducial markers available in real-time tumor-tracking radiation therapy (RTRT).
Ru M-edge resonant inelastic x-ray scattering (RIXS) measurements of α-RuClwith 27 meV resolution reveals a spin-orbit exciton without noticeable splitting. We extract values for the spin-orbit coupl...
The purpose of this research study is to evaluate placing the radiation therapy markers (Fiducial) by using an endoscopic procedure. The endoscopic procedure is called an Endoscopic Ultra...
It is a multicenter prospective observational study including consecutive patients with esophageal tumor or rectum with indication for radiotherapy The main objective of this study is to ...
To test the feasibility and accuracy of BioXmark fiducial markers for image guided radiotherapy (IGRT) based rectal tumor boosting in 20 patients referred for long course chemo-radiotherap...
In this pilot study the researchers will evaluate the safety and efficacy of 50% reduced fluence PDT combination therapy with ranibizumab. The researchers hope to gain information regardi...
The goal of this study is to establish the safety of high fluence LED-RL at fluence of 480 J/cm2 and 640 J/cm2 in healthy non-Hispanic, Caucasian subjects. The hypothesis is that high flue...
Materials used as reference points on or implanted in the body to position patients for radiotherapy.
Scattering of a beam of electromagnetic or acoustic RADIATION, or particles, at small angles by particles or cavities whose dimensions are many times as large as the wavelength of the radiation or the de Broglie wavelength of the scattered particles. Also know as low angle scattering. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Small angle scattering (SAS) techniques, small angle neutron (SANS), X-ray (SAXS), and light (SALS, or just LS) scattering, are used to characterize objects on a nanoscale.
Chemical analysis based on the phenomenon whereby light, passing through a medium with dispersed particles of a different refractive index from that of the medium, is attenuated in intensity by scattering. In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured. In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam.
The interactions of particles responsible for their scattering and transformations (decays and reactions). Because of interactions, an isolated particle may decay into other particles. Two particles passing near each other may transform, perhaps into the same particles but with changed momenta (elastic scattering) or into other particles (inelastic scattering). Interactions fall into three groups: strong, electromagnetic, and weak. (From McGraw-Hill Encyclopedia of Science & Technology, 7th ed)
Immunochemical analysis which measures specific target antigen bound to antibody complex. Antibodies in assay form insoluble light scattering immune-aggregates which cause changes in the measured turbidity proportional to the concentration of the antigen.
Radiology is the branch of medicine that studies imaging of the body; X-ray (basic, angiography, barium swallows), ultrasound, MRI, CT and PET. These imaging techniques can be used to diagnose, but also to treat a range of conditions, by allowing visuali...
Marburg and Ebola Virus Infections
Ebola virus and Marburg virus are related viruses that cause hemorrhagic fevers — illnesses marked by severe bleeding (hemorrhage), organ failure and, in many cases, death. Both viruses are native to Africa, where sporadic outbreaks have occurred f...