Sökning: "Radiation dose"

Visar resultat 1 - 5 av 229 uppsatser innehållade orden Radiation dose.

  1. 1. osimetric impact of system spe cific geometric distortion on head and neck treatment plans in MRI only based radiation therapy

    Master-uppsats,

    Författare :Jesper Brovall; [2022-01-13]
    Nyckelord :Medical physics; Dosimetry; MRI; Radiation therapy;

    Sammanfattning : Background/purpose:Because of the superior soft tissue contrast, in comparison withcomputed tomography (CT) data, magnetic resonance imaging(MRI) is of high interest to include in a larger extent in the ra diation therapy (RT) process. In an MRI only workflow, the CTscan is excluded and a synthetic CT is used for treatment plan ning. LÄS MER

  2. 2. ESTIMATION OF RADIATION EXPOSURE FROM NATURALLY OCCURRING RADIONUCLIDES IN FOOD AND FOODSTUFF

    Master-uppsats,

    Författare :Ida Bengtsson; [2022-01-13]
    Nyckelord :Medical physics; Naturally occurring radionuclides; committed effective dose from ingested radionuclides; Biokinetic models;

    Sammanfattning : Purpose: The main purpose of this study was to provide an estimation of the committed effective dose received by the Swedish population from naturally occurring radionuclides (NORM) in the diet. This study was also aiming to investigate the impact on the committed effective dose due to the new developments in the biokinetic model for Po 210. LÄS MER

  3. 3. STANDARDIZED ORGAN AT RISK VOLUME FOR EXTERNAL BEAM RADIATION THERAPY IN PROSTATE CANCER AND ITS RELATIONSHIP TO VOLUMES DEFINED BY CLINICAL PRACTICE

    Master-uppsats,

    Författare :Dang Thao; [2022-01-13]
    Nyckelord :Medical physics; Radiation therapy; Prostate cancer; Organs at risk;

    Sammanfattning : Background/Purpose:In radiation therapy (RT), the radiation dose calculated in tumours and normal tissue depends on how the volumes are defined. It is difficult to standardize how tumour volumes should be defined because their anatomical extension can differ greatly between individuals. LÄS MER

  4. 4. COMPARISON OF MULTI-CRITERIA OPTIMIZATION IN TWO DIFFERENT TREATMENT PLANNING SYSTEMS

    Master-uppsats,

    Författare :Anna Lindström; [2021-05-10]
    Nyckelord :Medical physics; Multi-criteria optimization; Pareto front; volumetric modulated arc therapy; head and neck cancer; prostate cancer;

    Sammanfattning : Purpose: The purpose with this study was to compare multi-criteria optimization (MCO) for volumetric modulated arc therapy (VMAT) treatment plans in two different treatment planning systems. Theory: When performing treatment planning prior to radiation therapy it is important to prioritize between absorbed dose to target and absorbed dose to organs at risk (OAR). LÄS MER

  5. 5. FETAL DOSE ESTIMATION IN ABDOMINAL AND PELVIC CT EXAMINATIONS

    Master-uppsats,

    Författare :Olivia Carlstein; [2021-05-10]
    Nyckelord :Medical physics; Fetal dose; abdominal CT examination; pelvic CT examination; phantom measurement;

    Sammanfattning : Purpose: The purpose of this is study was to compare different methods for estimating the fetal dose, how much the different methods differ from each other and on which dose levels the fetal doses are estimated to. Theory: A radiological procedure should always be justified and in the case of a pregnant patient the justification should include both the mother and the fetus. LÄS MER