Sökning: "MEDICIN Fysiologi och farmakologi Radiologisk forskning Radiofysik"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden MEDICIN Fysiologi och farmakologi Radiologisk forskning Radiofysik.

  1. 1. Energy and intensity modulated radiation therapy with electrons

    Detta är en avhandling från Umeå : Umeå universitet

    Författare :Lennart Olofsson; Mikael Karlsson; Magnus Karlsson; Björn Zackrisson; Erik Traneus; [2005]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiation sciences; Radiation therapy; Conformal therapy; IMRT; Electrons; Electron treatment head; Electron MLC; Bremsstrahlung reduction; Integral dose; Penumbra; Output factor; Strålningsvetenskap; MEDICINE Physiology and pharmacology Radiological research Radiation biology; MEDICIN Fysiologi och farmakologi Radiologisk forskning Strålningsbiologi; radiofysik; radiation physics;

    Sammanfattning : In recent years intensity modulated radiation therapy with photons (xIMRT) has gained attention due to its ability to reduce the dose in the tissues close to the tumour volume. However, this technique also results in a large low dose volume. LÄS MER

  2. 2. Theoretical modelling of tumour oxygenation and influences on treatment outcome

    Detta är en avhandling från Umeå : Umeå universitet

    Författare :Iuliana Toma-Dasu; Mikael Karlsson; Svensson Hans; J F Fowler; Borivoj Vojnovic; [2004]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiation sciences; Computer simulation; Electrode; Polarographic measurements; Tumour oxygenation; Hypoxia; Strålningsvetenskap; MEDICINE Physiology and pharmacology Radiological research Radiation biology; MEDICIN Fysiologi och farmakologi Radiologisk forskning Strålningsbiologi; radiofysik; radiation physics;

    Sammanfattning : One of the main problems in curing cancer resides in the different microenvironment existing in tumours compared to the normal tissues. The mechanisms of failure are different for radiotherapy and chemotherapy, but they all relate to the poor blood supply known to exist in tumours. LÄS MER

  3. 3. Improving accuracy of in situ gamma-ray spectrometry

    Detta är en avhandling från Umeå : Radiofysik

    Författare :Jonas Boson; Christer Samuelsson; [2008]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; gamma-ray spectrometry; in situ measurement; HPGe detector; 137Cs; Monte Carlo; efficiency calibration; measurement uncertainty; MEDICINE Physiology and pharmacology Radiological research Radiological physics; MEDICIN Fysiologi och farmakologi Radiologisk forskning Radiofysik;

    Sammanfattning : Gamma-ray spectrometry measurements performed on site, or “in situ”, is a widely used and powerful method that can be employed both to identify and quantify ground deposited radionuclides. The purpose of this thesis is to improve the calibration of high purity germanium (HPGe) detectors for in situ measurements, and calculate the combined uncertainty and potential systematic effects. LÄS MER

  4. 4. Modeling Silicon Diode Dose Response in Radiotherapy Fields using Fluence Pencil Kernels

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Karin Eklund; Anders Ahnesjö; Erik Grusell; Hugo Palmans; [2010]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICINE Physiology and pharmacology Radiological research Radiological physics; MEDICIN Fysiologi och farmakologi Radiologisk forskning Radiofysik; Medicinsk radiofysik; Medical Radiophysics;

    Sammanfattning : In radiotherapy, cancer is treated with ionizing radiation, most commonly bremsstrahlung photons from electrons of several MeV. Secondary electrons produced in photon-interactions results in dose deposition. The treatment response is low for low doses, raises sharply for normal treatment doses and saturates at higher doses. LÄS MER

  5. 5. Calibration of Ionization Chambers for Measuring Air Kerma Integrated over Beam Area in Diagnostic Radiology

    Detta är en avhandling från Institutionen för medicin och vård

    Författare :Peter Larsson; Gudrun Alm Carlsson; Jan Persliden; Bertil Axelsson; [2006]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; KAP-meter; DAP-meter; PKA; kerma area product; energy dependence; calibration; MEDICINE Physiology and pharmacology Radiological research Radiological physics; MEDICIN Fysiologi och farmakologi Radiologisk forskning Radiofysik;

    Sammanfattning : The air kerma area product PKA is an important quantity used by hospital physicists in quality assurance and optimization processes in diagnostic radiology and is recommended by national authorities for setting of diagnostic reference levels. PKA can be measured using a transmission ionization chamber (kerma area product (KAP) meter) mounted on the collimator housing. LÄS MER