We propose a patient-specific planning target volume (PTV) to deal with interfractional variations, and test its feasibility in a retrospective treatment-planning study. Instead of using one planning image only, multiple scans are taken on different days. The target and organs at risk (OARs) are delineated on each images. The proposed PTV is generated from a union of those target contours on th...

Introduction: Background: Radiotherapy of parotid tumors is achieved by different radiotherapy techniques. So they deliver the dose to organs at risk such as contralateral parotid, temporal lobe & spinal cord. The consequences of high dose to OARs are xerostomia, Temporal lobe necrosis and loss of hearing. Purpose: The aim of this study was to compare different treatment tech...

The accurate contour delineation of the target and/or organs at risk (OAR) is essential in treatment planning for image-guided radiation therapy (IGRT). Although many automatic contour delineation approaches have been proposed, few of them can fulfill the necessities of applications in terms of accuracy and efficiency. Moreover, clinicians would like to analyze the characteristics of regions of...

Background: Brachytherapy treatment planning in cervix carcinoma patients using two dimensional (2D) orthogonal images provides only point dose estimates while CT-based planning provides volumetric dose assessment helping in understanding the correlation between morbidity and the dose to organs at risk (OARs) and treatment volume. Objective: Aim of present study is to compare Internationa...

Introduction: One of the treatment choices in breast cancer is Intra operative electron beam radiation therapy (IOERT). Due to high dose delivery in this procedure, shielding disk is used to protect organs at risk (OARs). In this study, we evaluate the OARs dose in the breast IOERT using Monte Carlo simulation with and without shielding disk in RANDO phantom. Material and Methods: Simulation ...

Background: The grading evaluation of atlas based auto-segmentation (ABAS) of organs at risk (OARs) in thorax was studied. Materials and Methods: Forty patients with thoracic cancer were included in this study, and for each thirteen thoracic OARs were delineated by an experienced radiation oncologist. The patients were randomly grouped into the training and the test dataset (20 each). The inves...

This study is to investigate the dose distribution of organs at risk (OARs) in cases of nasopharyngeal carcinoma (NPC). From July 2013 to October 2014, a prospective cohort study involving 148 patients was carried out at our center. OARs surrounding the nasopharynx were contoured on axial CT planning images in all patients. Dose-volume histograms of OARs and gross tumor volumes (GTV) were calcu...

Radiotherapy is a treatment where radiation used to eliminate cancer cells. The delineation of organs-at-risk (OARs) vital step in radiotherapy planning avoid damage healthy organs. For nasopharyngeal cancer, more than 20 OARs are needed be precisely segmented advance. challenge this task lies complex anatomical structure, low-contrast organ contours, and the extremely imbalanced size between l...

Three dimensional planning for high-dose-rate (HDR) brachytherapy in cervical cancer has been highly recommended by consensus guidelines such as the American Brachytherapy Society (ABS) and the Groupe Européen de Curiethérapie - European Society for Radiotherapy and Oncology (GEC-ESTRO). In this document, we describe our experience with computed tomography (CT)-based planning using the tandem/r...