Search results for "Contouring"

Requirement and postoperative outcomes of abdominal panniculectomy alone or in combination with other procedures in a bariatric surgery unit.

2009

Abstract Background A high percentage of patients present with redundant skin folds after bariatric surgery. This study aims to quantify the need for panniculectomy after open bariatric surgery and to analyze the postoperative outcomes. Methods A retrospective cohort study was performed. The patients were divided into 2 groups: group DLP, patients who underwent an abdominal panniculectomy alone and group DLP+, those who underwent panniculectomy in association with another surgical procedure. Results Four hundred forty-six patients underwent open bariatric surgery and 130 patients (29%) subsequently required an abdominal dermolipectomy. Seventy-six percent presented also incisional hernia an…

Cone-beam computed tomography in lung stereotactic ablative radiation therapy: predictive parameters of early response

2016

To analyze lung lesion volume variations by contouring on cone-beam CT (CBCT) images to evaluate the early predictive parameters of stereotactic ablative radiation therapy (SABR) treatment response.The prescribed dose of SABR was varied according to the tumour site (central or peripheral) and maximum diameter of the lesions by using a strategy of risk-adapted dose prescription with a dose range between 48 and 70 Gy in 3-10 consecutive fractions. For the purpose of the analysis, the gross tumour volume (GTV) was recontoured for each patient at first and last CBCT using two lung levels/windows: (a) -600/1000 HU and (b) -1000/250 HU. Univariate analysis was performed to evaluate a correlation …

Model of a CNC Feed Drive for On-Site Tuning of the Controllers for Single Axis Motion

2016

The accuracy of CNC machine-tools is heavily influenced by the correct tuning of the feed drives controllers. While an initial tuning is performed by the machine-tool manufactures, in time the values have to be changed by the user in order to preserve positioning and contouring accuracy of the machine. This paper presents a model of a CNC feed drive, for a particular CNC machine-tool, but with a high degree of generality. The objective is to provide the user the necessary knowledge, together with a simple, yet accurate simulation tool, in order to assist him in the process of tuning the controllers.

9 Development of an experimental tool to evaluate normal tissue 3D doses in external-beam radiotherapy

2018

Introduction Recently, cancer treatment improvement enabled an increase in patients’ survival rate. In more than half of the cases, radiotherapy participates in the cure for cancer. The efficacy of this technique is well known but it inevitably delivers doses to normal tissues exposing them to radio-induced complications risks [1] . Moreover, the longer patients’ life expectancy increases the risk of developing long-term complications such as second cancers. Thus, evaluating the risks following cancer treatment involving radiotherapy constitutes a major challenge. In this context, an experimental tool has been developed to evaluate normal tissue doses delivered by the different radiotherapy…

SU-FF-T-365: Practical Reconstruction Method for 3D CT-Based Brachytherapy with Shielded Colpostats

2006

Introduction and purpose.‐ The most extended worldwide HDR and PDR afterloading machines are from Nucletron, using the Plato Treatment Planning System (TPS) to perform the clinical dosimetry. The Fletcher‐Williamson (FW) vaginal colpostat applicators are widely used with these machines, they are made of a very dense material (densimet‐17) which allows shielding up to 50% of the dose. Almost all the TPS have incorporated the CT‐Based Brachytherapy (BT), in which the CT catheters and applicators reconstruction is based on contiguous CT transverse slices where the user points the catheter position. The problem with these applicators is the production of artefacts that makes the reconstruction …

2020

One crucial parameter to evaluate the state of the heart after myocardial infarction (MI) is the viability of the myocardial segment, i.e., if the segment recovers its functionality upon revascularization. MRI performed several minutes after the injection of a contrast agent (delayed enhancement-MRI or DE-MRI) is a method of choice to evaluate the extent of MI, and by extension, to assess viable tissues after an injury. The Emidec dataset is composed of a series of exams with DE-MR images in short axis orientation covering the left ventricle from normal cases or patients with myocardial infarction, with the contouring of the myocardium and diseased areas (if present) from experts in the dom…

Mechatronic Contouring System for Unconventional Sheet Metal Forming Processes

2006

This paperwork was developed in order to present the work concerning the use of mechatronic approach in the study of motion control systems for metal forming processes. The paper presents the use of low cost motion control systems, based upon induction motors, as driving systems in unconventional sheet metal forming processes. The main goal of this work was to implement a 2D contouring system for driving the active plate. The model of the system, simulations and some experimental work will be presented.

Researches Regarding Optimizing the Accuracy of CNC Laser Cutting Machines

2015

The experimental researches presented in this paper are aimed to improve the manufacturing accuracy of a contouring machine together with an approach to eliminate the errors which lead to a less precise part after machining.In order to eliminate the errors, the machine's feed drives were tuned leading to a more precise part. In order to validate the proposed approach, the accuracy of the machine was tested before and after the tuning process.

Fat Transplantion: Different Clinical Applications to Achieve Symmetry in Face and Body Contouring

2008

Introduction: Fat autograft was first described in 1893 by Neuber for cosmetic and congenital defects. Nowadays its use is becoming widespread for soft tissue augmentation to improve simmetry and contour in all areas of the face and body. The authors present their experience with face and body contouring by fat autograft in post-oncological, post-traumatic and cosmetic settings. Materials and Methods: Between 2005 and 2008 31 patients underwent fat autografting in the plastic surgery unit of the university of palermo. There were 10 cases of breast asimmetry after reduction mammaplasty, breast augmentation and breast recostruction; 3 cases of post-traumatic and 1 congenital deformities in th…

Impact of rectal distension on prostate CBCT-based positioning assessed with 6 degrees-of-freedom couch

2018

International audience; Introduction: Prostate requires a daily correction of its 3-dimensional position in relation with rectal distension. In this study, we sought to determine whether rectal distension with respect to the rectal behavior might have an impact on prostate translations and/or rotations during prostate image guided radiation therapy using a 6 degrees-of-freedom (DOF) couch.Methods and materials: We reviewed the data from 39 patients with localized prostate cancer treated with protracted external radiation therapy using a 6 DOF couch. Before each fraction, a kilovoltage cone beam computed tomography (kV-CBCT) scan was performed. The automatic fusion algorithm was set to fuse …