نتایج جستجو برای: 3D Conformal

تعداد نتایج: 209316  

Introduction: The commonly used technique of radiation therapy for vulvar cancer consists of anteroposterior (AP) and posteroanterior (PA) fields. This is the first study that reports the dosimetric comparison between the AP-PA techniques and the new 3D advanced conformal technique (3D-ACT) based on the multiplicity of treatment fields in patients with squamous cell ca...

Journal: :iranian journal of radiation research 0
s.a. vaezzadeh department of medical physics and biomedical engineering, tehran university of medical sciences, tehran, iran m. allahverdi department of medical physics and biomedical engineering, tehran university of medical sciences, tehran, iran h.a. nedaie department of radiotherapy – oncology, tehran university of medical sciences, tehran, iran m. aghili department of radiotherapy – oncology, tehran university of medical sciences, tehran, iran m. esfehani department of radiotherapy – oncology, tehran university of medical sciences, tehran, iran

background: to evaluate the dosimetric difference between conventional and three-dimensional conformal radiotherapy (3d-crt) using 6 and 18 mv x-ray photons. materials and methods: computed tomography scans of 26 pelvic patients were acquired and transferred to the 3d treatment planning system. for each patient, 8 conventional plans (3, 4, 5 and 6 fields) and one 3d-crt plan were prepared using...

Ali Jomehzadeh, Alireza Amouheidari Anton Mans Ben Mijnheer Mohammad Mohammadi, Parvaneh Shokrani

Introduction: The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans both pretreatment and in-vivo. The aim of this study was to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in-vivo, as well. Materials and Methods: </strong...

Background: Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) techniques are used for the treatment of patients with laryngeal cancer. Objective: This study aimed to investigate the effects of these 2 treatment techniques on the planning target volume (PTV) (laryngeal cancer), dose homogeneity, dose of organs at...

Journal: :iranian journal of radiation research 0
m. izmirli yuzuncu yıl university, school of medicine, department of radiation oncology, 65080/van, turkey g. yilmazer yuzuncu yıl university, school of medicine, department of radiation oncology, 65080/van, turkey t. cakir yuzuncu yıl university, school of medicine, department of radiation oncology, 65080/van, turkey z.a. palabiyik yuzuncu yıl university, school of medicine, department of radiation oncology, 65080/van, turkey m. nart yuzuncu yıl university, school of medicine, department of radiation oncology, 65080/van, turkey

aims: it was aimed to investigate postoperative conformal radiotherapy planning that provides the best target volume and the least dose for critical organs in cancers of stomach. methods: this study was conducted on the ct simulation images of thirty patients diagnosed with gastric cancer. target volumes and the organs at risk were contoured. ap-pa reciprocal parallel field conventional plan an...

G. Yilmazer, M. Izmirli, M. Nart, T. Cakir, Z.A. Palabiyik,

Aims: It was aimed to investigate postoperative conformal radiotherapy planning that provides the best target volume and the least dose for critical organs in cancers of stomach. Methods: This study was conducted on the CT simulation images of thirty patients diagnosed with gastric cancer. Target volumes and the organs at risk were contoured. AP-PA reciprocal parallel field conventional plan an...

Journal: :CoRR 2015
Mei-Heng Yueh Xianfeng Gu Wen-Wei Lin Chin-Tien Wu Shing-Tung Yau

Morphing is the process of changing one figure into another. Some numerical methods of 3D surface morphing by deformable modeling and conformal mapping are shown in this study. It is well known that there exists a unique Riemann conformal mapping from a simply connected surface into a unit disk by the Riemann mapping theorem. The dilation and relative orientations of the 3D surfaces can be link...

Journal: :Pattern Recognition 2007
Hongdong Li Richard I. Hartley

This paper describes an approach of representing 3D shape by using a set of invariant Spherical Harmonic (SH) coefficients after conformal mapping. Specifically, a genus-zero 3D mesh object is first conformally mapped onto the unit sphere by using a modified discrete conformal mapping, where the modification is based on Möbius Factorization and is aimed at obtaining a canonical conformal mappin...

Ahmad Bitarafan rajabi Khadijeh Bamneshin, Parham Geramifar Seied Rabi Mahdavi,

Introduction: Modern radiotherapy (RT) techniques allow a highly precise deposition of the radiation dose in tumor. So, high conformal tumor doses can be reached while sparing critical organs at risk. Materials and Methods: This study was conducted in three phases. In the first phase; Fourteen patients with primary or recurrent prostate cancer receive Gallium-...

Journal: :CoRR 2012
Lok Ming Lui Chengfeng Wen Xianfeng Gu

We address the problem of surface inpainting, which aims to fill in holes or missing regions on a Riemann surface based on its surface geometry. In practical situation, surfaces obtained from range scanners often have holes or missing regions where the 3D models are incomplete. In order to analyze the 3D shapes effectively, restoring the incomplete shape by filling in the surface holes is neces...

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