Geri Dön

Optimization of radiotherapy considering uncertainties caused by daily setup procedures and organ motion

Başlık çevirisi mevcut değil.

  1. Tez No: 400962
  2. Yazar: MUSTAFA YAŞAR SIR
  3. Danışmanlar: PROF. MARINA EPELMAN, PROF. STEPHEN POLLOCK
  4. Tez Türü: Doktora
  5. Konular: Endüstri ve Endüstri Mühendisliği, Industrial and Industrial Engineering
  6. Anahtar Kelimeler: Belirtilmemiş.
  7. Yıl: 2007
  8. Dil: İngilizce
  9. Üniversite: University of Michigan
  10. Enstitü: Yurtdışı Enstitü
  11. Ana Bilim Dalı: Belirtilmemiş.
  12. Bilim Dalı: Belirtilmemiş.
  13. Sayfa Sayısı: 224

Özet

Özet yok.

Özet (Çeviri)

Most existing intensity-modulated radiation therapy (IMRT) optimization methods assume that the shape and location of the patient anatomy do not change throughout the treatment course and typically produce solutions containing sharp dose gradients between a tumor and its neighboring healthy tissue. Uncertainties caused by the daily setup procedures and organ motion, however, can lead to significant differences between the dose distribution as calculated by a treatment plan and the actual dose distribution delivered to a patient. Using weighted power loss functions as a measure of performance for a treatment plan, a simple method of calculating the ideal spatial dose distribution when there is positional uncertainty is presented. Immediate results are qualitative insights into the suitability of using a margin to compensate for uncertainties at all, and (if one is to be used) how to select a“good”margin size. Moreover, it is shown that the common practice of raising power parameters in the treatment loss function, in order to enforce target dose requirements, is counter-productive. These insights into desirable dose distributions could be used, in conjunction with well-established inverse radiotherapy planning techniques, to produce dose distributions that are more adept at dealing with uncertainties. Furthermore, techniques that exploit the dynamic nature of radiotherapy and information gathering by adapting the treatment plan to variations measured during the treatment course of an individual patient are developed. This problem, called off-line adaptive treatment planning, is structured within a dynamic programming (DP) framework. Several (suboptimal) control policies, which are obtained using an approximation to the underlying DP and computationally feasible to implement, are presented and compared. The common properties shared by these policies are that they all • perform a re-optimization of beamlet intensities before each fraction, • use Bayesian updating of the individual patient's setup variation parameters, • use“Multiple Instance of Geometry Approximation”as the model of uncertainty. These policies only differ in their re-optimization schemes, of which there are three major variants: certainty equivalent control, open-loop feedback control, and cost-to-go approximation via Lagrangian relaxation. Computational experiments show that these individualized adaptive radiotherapy plans promise considerable improvements over non-adaptive treatment plans.

Benzer Tezler

  1. Optimization approaches for planning external beam radiotherapy

    Başlık çevirisi yok

    HALİL OZAN GÖZBAŞI

    Doktora

    İngilizce

    İngilizce

    2010

    Endüstri ve Endüstri MühendisliğiGeorgia Institute of Technology

    DR. SHABBIR AHMED

    DR. MARTIN SAVELSBERGH

  2. Düzleştirici filtresiz tedavi sistemleri için kalem huzme kerneli geliştirilmesi

    Development of pencil beam kernel for flattening filter free treatment systems

    MEHMET ERTUĞRUL ERTÜRK

    Doktora

    Türkçe

    Türkçe

    2019

    Nükleer MühendislikHacettepe Üniversitesi

    Nükleer Enerji Mühendisliği Ana Bilim Dalı

    PROF. DR. CEMİL KOCAR

    PROF. DR. MEHMET TOMBAKOĞLU

  3. İntrakranial tümörlerin Halcyon cihazı ile yoğunluk ayarlı volumetrik ark ışınlamalarında plan kalitesinin araştırılması

    Evaluation of plan quality for intracranial tumors treated in intensity-modulated volumetric arc radiotherapy with Halcyon

    SELEN ENER

    Yüksek Lisans

    Türkçe

    Türkçe

    2023

    Fizik ve Fizik Mühendisliğiİstanbul Üniversitesi

    Temel Onkoloji Ana Bilim Dalı

    PROF. DR. HATİCE BİLGE BECERİR

  4. Uzun dönem rektum kanseri radyoterapisinde kemik iliği dozlarının farklı tedavi teknikleriyle karşılaştırılması

    Dosimetric comparison of bone marrow doses with different treatment techniques in long term rectal cancer radiotherapy

    TURGUT TAŞÇİ

    Yüksek Lisans

    Türkçe

    Türkçe

    2021

    Fizik ve Fizik Mühendisliğiİstanbul Üniversitesi

    Onkoloji Ana Bilim Dalı

    DR. ÖĞR. ÜYESİ NAZMİYE DÖNMEZ KESEN

  5. Meme ve ovaryum hücre hatlarında klorambusil ve tamoksifen'in etkisinin incelenmesi

    Investigation of the effect of chlorambucil and tamoxifen on breast and ovarian cell lines

    DURMUŞ BURAK DEMİRKAYA

    Yüksek Lisans

    Türkçe

    Türkçe

    2023

    BiyolojiKırşehir Ahi Evran Üniversitesi

    Moleküler Biyokimya ve Genetik Ana Bilim Dalı

    PROF. DR. SERAP YALÇIN AZARKAN