Sökning: "Strålterapi"

Visar resultat 21 - 25 av 67 uppsatser innehållade ordet Strålterapi.

  1. 21. Dual Energy CT as a Foundation for Proton Therapy Treatmen Planning - A pilot study

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Torbjörn Näsmark; [2019]
    Nyckelord :Dual Energy CT; DECT; Computed Tomography; CT; Proton Therapy; Skandion;

    Sammanfattning : The treatment plan for radiation therapy with protons is based on images from a computed tomography (CT) scanner. This is problematic since the photons in the x-ray beam from the CT scanner and the protons are affected differently by the tissue in the patient, which introduce an uncertainty in the track length of the protons. LÄS MER

  3. 22. Generative Models and Feature Extraction on Patient Images and Structure Data in Radiation Therapy

    Master-uppsats, KTH/Matematisk statistik

    Författare :Hanna Gruselius; [2018]
    Nyckelord :Variational Autoencoder; Feature extraction; Deep learning on medical images; Computed tomography; Radiation therapy;

    Sammanfattning : This Master thesis focuses on generative models for medical patient data for radiation therapy. The objective with the project is to implement and investigate the characteristics of a Variational Autoencoder applied to this diverse and versatile data. LÄS MER

  4. 23. Direct optimization of dose-volume histogram metrics in intensity modulated radiation therapy treatment planning

    Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Tianfang Zhang; [2018]
    Nyckelord :Optimization; intensity-modulated radiation therapy; DVH functions; dose-at-volume; volume-at-dose; value-at-risk; smooth approximation; kernel density estimation; fluence map optimization; Optimering; intensitetsmodulerad strålterapi; DVH-funktioner; dose-at-volume; volumeat- dose; value-at-risk; slätapproximation; ickeparametrisk skattning; fluensoptimering;

    Sammanfattning : In optimization of intensity-modulated radiation therapy treatment plans, dose-volumehistogram (DVH) functions are often used as objective functions to minimize the violationof dose-volume criteria. Neither DVH functions nor dose-volume criteria, however,are ideal for gradient-based optimization as the former are not continuously differentiableand the latter are discontinuous functions of dose, apart from both beingnonconvex. LÄS MER

  5. 24. Evaluation of Tomodirect for treatment of thoracic and abdominal cases

    Master-uppsats, Lunds universitet/Sjukhusfysikerutbildningen

    Författare :Sara Talozi; [2018]
    Nyckelord :Medicine and Health Sciences;

    Sammanfattning : Sedan 1970-talet har antalet rapporterade cancerfall dubblerats, dels på grund av förändrade levnadsvanor och dels på grund av bättre screeningmetoder som upptäcker cancern i tidigt skede. Tidig upptäckt av cancern i kombination med utvecklad cancerbehandling har bidragit till att risken för att avlida av cancer har minskat. LÄS MER

  7. 25. Robust optimization of radiotherapy treatment plans considering time structures of the delivery

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Avdelningen för datalogi

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

    Sammanfattning : 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. LÄS MER