Sökning: "photon pencil beams"

Hittade 4 avhandlingar innehållade orden photon pencil beams.

  1. 1. Development and application of composite energy deposition kernels for photon therapy planning

    Författare :Anders Eklöf; Simo Hyödynmaa; Stockholms universitet; []
    Nyckelord :Energy deposition kernels; volume overlap algorithm; radiotherapy planning; photon pencil beams; treatment optimization; biological treatment objectives; medicinsk strålningsfysik; Medical Radiation Physics;

    Sammanfattning : In recent years, the use of optimization algorithms in radiation therapy planning has increased dramatically. All optimization algorithms as well as most modern implementations of conventional therapy planning, use energy deposition kernels as a fundamental part of the calculations. LÄS MER

  3. 2. Developing and evaluating dose calculation models for verification of advanced radiotherapy

    Författare :Jörgen Olofsson; Mikael Karlsson; Anders Ahnesjö; Crister Ceberg; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiation therapy; high-energy photons; dose calculation; multi-source model; pencil kernel; uncertainties; action levels; Radiological physics; Radiofysik;

    Sammanfattning : A prerequisite for modern radiotherapy is the ability to accurately determine the absorbed dose (D) that is given to the patient. The subject of this thesis has been to develop and evaluate efficient dose calculation models for high-energy photon beams delivered by linear accelerators. LÄS MER

  4. 3. Fast neutron dosimetry : a study of basic dosimetric properties of fast-neutrons for external beam radiotherapy and problems associated with corrections of measured charged particle cross-sections

    Författare :Jonas Söderberg; Lennart Lindborg; Linköpings universitet; []
    Nyckelord :MEDICINE; MEDICIN;

    Sammanfattning : Basic dosimetric properties of fast-neutron beams with energies ≤80 MeV were explored using Monte Carlo techniques. Elementary pencil-beam dose distributions taking into account transport of all relevant types of released charged particles (protons, deuterons, tritons, 3He and a particles) were calculated and used to derive several absorbed dose distributions. LÄS MER

  5. 4. Dosimetry and radiation quality in fast-neutron radiation therapy : A study of radiation quality and basic dosimetric properties of fast-neutrons for external beam radiotherapy and problems associated with corrections of measured charged particle cross-sections

    Författare :Jonas Söderberg; Gudrun Alm Carlsson; Crister Ceberg; Linköpings universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neutron; Dosimetry; Radiotherapy; Monte Carlo; Microdosimetry; Cross-section; RBE; LET; Energy-loss corrections; Radiological physics; Radiofysik;

    Sammanfattning : The dosimetric properties of fast-neutron beams with energies ≤80 MeV were explored using Monte Carlo techniques. Taking into account transport of all relevant types of released charged particles (electrons, protons, deuterons, tritons, 3He and α particles) pencil-beam dose distributions were derived and used to calculate absorbed dose distributions. LÄS MER