Essays about: "collimator"

Showing result 11 - 15 of 38 essays containing the word collimator.

  1. 11. Spatial Frequency-Based Objective Function for Optimization of Dose Heterogeneity in Grid Therapy

    University essay from Stockholms universitet/Fysikum

    Author : Fredén Emil; [2019]
    Keywords : Radiotherapy; Dose Optimization; Objective function; Dose Heterogeneity; Proton Grid Therapy; Spatially Fractionated Radiotherapy; SFRT;

    Abstract : In this project we introduced a spatial frequency-based objective function for optimization of dose distributions used in spatially fractionated radiotherapy (also known as grid therapy). Several studies indicate that tissues can tolerate larger mean doses of radiation if the dose is delivered heterogeneously or to a partial volume of the organ. READ MORE

  3. 12. Robust optimization of radiotherapy treatment plans considering time structures of the delivery

    University essay from Uppsala universitet/Avdelningen för datalogi

    Author : Erik Orvehed Hiltunen; [2018]
    Keywords : Radiation therapy; optimization; interplay effect; lung cancer; 4DCT; RayStation; Strålterapi; optimering; interplay; lungcancer;

    Abstract : Cancer is the second largest mortal disease in Sweden, and high efforts are made to develop the treatment of cancer. One of the main treatment methods is radiotherapy, which uses ionizing radiation to damage the cancerous cells. This has the chance of stopping the cell reproduction, and the goal is to reduce the tumor and stop the tumor growth. READ MORE

  4. 13. On the usage of a photon counting CT detector for SPECT

    University essay from KTH/Skolan för teknikvetenskap (SCI)

    Author : Måns Andersson; [2017]
    Keywords : ;

    Abstract : This work explores the possibility of using a photon counting silicon detector developedfor Computer Tomography (CT) in Single Photon Emission Computed Tomography(SPECT) applications. This would allow for a more versatile and a much cheapersystem. The main focus is on determining the efficiency and resolution of such a system. READ MORE

  5. 14. Monte Carlo simulation of the spatial response function of a SPECT measurement device for nuclear fuel bundles

    University essay from Stockholms universitet/Fysikum

    Author : Emilie Dul; [2017]
    Keywords : Monte Carlo MCNPX Safeguards;

    Abstract : The PGET device is currently being developed for partial-defect verication purposes on nuclear fuel assemblies. It Comprises CdTe detector elements in a heavy tungsten-alloy collimator, for which collimator slit openings define the field-of-view. READ MORE

  6. 15. Utilizing the Degrees of Freedom in Radiation Therapy Optimization

    University essay from KTH/Optimeringslära och systemteori

    Author : Henrik Olsson; [2017]
    Keywords : ;

    Abstract : The development of advanced software for radiation therapy treatment has had a significant role in the last decades’ improvements in cancer treatment. By optimizing the radiation dose given to each patient, the probability of a successful treatment increases. READ MORE