Dosimetric Impact of Geometric Distortionsin an MRI-Only Proton Therapy Workflowfor Extracranial Sites
Başlık çevirisi mevcut değil.
- Tez No: 785515
- Danışmanlar: PROF. GUİDO BARONI, PROF. MARCO RIBOLDI, DR. CHİARA PAGANELLI
- Tez Türü: Yüksek Lisans
- Konular: Biyomühendislik, Bioengineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2020
- Dil: İngilizce
- Üniversite: Politecnico di Milano
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 148
Özet
Özet yok.
Özet (Çeviri)
In a magnetic resonance imaging (MRI) only radiation therapy workflow, dosimetric errors may arise due to system-dependent and patient-dependent geometric distortions introduced by MRI. The aim of this study was to quantify the dosimetric effect of geometric distortions arising from MRI in MRI-only workflow in Intensity Modulated Proton Therapy (IMPT). An approach was developed, in which computer tomography (CT) images were distorted using an MRI displacement map representing MR distortions due to gradient nonlinearities, static magnetic field inhomogeneities and patient susceptibility variations. The maximal mean landmark deformation per image slice was up to 3mm in slice selection direction at a slice shifted 105mm away from the isocenter and mean in-slice landmark deformation was below 1 mm. A retrospective study was conducted on 4DCT/MRI digital phantoms and 4DCT clinical dataset of the thoraco-abdominal site. The treatment plans were designed and separately optimized for each beam field on a beam specific Planning Target Volume (bsPTV) on the distorted CT, and the final dose distribution was obtained as the average. Dose was then recalculated in undistorted CT using the same beam geometry and beam weights. The analysis was performed in terms of Dose Volume Histogram (DVH) parameters of target and organs at risk (OARs). No clinically relevant dosimetric impact was observed on OARs. Small dosimetric changes due to geometric distortions were found in the abdominal and thorax cases, where the tumor was closed or covered by the soft tissue, whereas higher changes were observed for lung cases where the tumor was isolated inside the lung parenchyma due to higher density variations along the beam path. Results suggest the potential applicability of MRI-only proton therapy, provided that further analyses would be performed for isolated lung tumors.
Benzer Tezler
- Farklı tedavi algortimalarının SRS ve SBRT tedavi planlamalarına etkisinin dozimetrik incelenmesi
Dosimetric impact of different dose calculation algorithms in SRS and sbrt treatment plans
ESRA LALEŞAHİN
Yüksek Lisans
Türkçe
2017
Fizik ve Fizik Mühendisliğiİstanbul Medipol ÜniversitesiSağlık Fiziği Ana Bilim Dalı
DOÇ. DR. HİLAL ACAR DEMİR
- Kontrast maddenin dozimetrik etkisi
Dosimetric impact of contrast agent
YUNUS TARIK ÇETİNOĞLU
Yüksek Lisans
Türkçe
2016
Fizik ve Fizik MühendisliğiAcıbadem ÜniversitesiRadyasyon Onkolojisi Ana Bilim Dalı
PROF. DR. ENİS ÖZYAR
- Radyoterapi ile tedavi edilen baş boyun kanserlerinde tedavi süresinde oluşan anatomik değişikliklerin doz dağılımına etkisi
The impact of anatomical changes during treatment on dose distribution in head and neck cancers treated with radiotherapy
SEVİM ÖZDEMİR
Tıpta Uzmanlık
Türkçe
2013
Onkolojiİstanbul ÜniversitesiRadyoloji Onkolojisi Ana Bilim Dalı
PROF. DR. ÖMER UZEL
- Vücut içerisindeki doku eşdeğeri olmayan implant materyallerinin yoğunluk ayarlı radyoterapi ve stereotaktik radyocerrahi tedavilerinde doz dağılımına etkisinin incelenmesi
Evaluation of the impact of non tissue equivalent implant and filling materials on the dose distribution of intensity modulated radiotherapy and stereotactic radio surgery
MAHMUT SERDAR ŞİŞECİOĞLU
Yüksek Lisans
Türkçe
2015
OnkolojiHacettepe ÜniversitesiKlinik Onkoloji Ana Bilim Dalı
PROF. DR. FERAH YILDIZ
- Serviks kanserinin İntrakaviter Brakiterapi'sinde bilgisayar tomografi ile uyumlu aplikatörler kullanılarak doz dağılımının üç boyutlu incelenmesi ve bacak pozisyonunun doz dağılımına etkisi
Evaluation of three dimensional computerized tomograhy based plans of intracavitary brachytherapy for cervical cancer and the effect of patient?s leg position on the dose distribution
FATMA ÇOLAK
Yüksek Lisans
Türkçe
2008
OnkolojiHacettepe ÜniversitesiKlinik Onkoloji Ana Bilim Dalı
DOÇ. DR. MUSTAFA CENGİZ