نتایج جستجو برای: dose volume constraints

تعداد نتایج: 787080  

Journal: :Applied optics 2013
David J Brady Daniel L Marks Kenneth P MacCabe Joseph A O'Sullivan

We examine coding strategies for coded aperture scatter imagers. Scatter imaging enables tomography of compact regions from snapshot measurements. We present coded aperture designs for pencil and fan beam geometries, and compare their singular value spectra with that of the Radon transform and selected volume tomography. We show that under dose constraints scatter imaging improves conditioning ...

Background: in radiation treatment of moving targets located in thorax region of patient body, the delivered dose does not match with the planned treatment, resulting in some over and under dosage in the tumor volume, as a function of motion magnitude and frequency. Several efforts have been done to investigate the target motion effects on dose distribution in the target and surrounding normal ...

2013
Shyam Pokharel Suresh Rana Joseph Blikenstaff Amir Sadeghi Bradley Prestidge

The purpose of this study is to investigate the effectiveness of the HIPO planning and optimization algorithm for real-time prostate HDR brachytherapy. This study consists of 20 patients who underwent ultrasound-based real-time HDR brachytherapy of the prostate using the treatment planning system called Oncentra Prostate (SWIFT version 3.0). The treatment plans for all patients were optimized u...

Journal: :SIAM Journal on Optimization 1998
Masao Fukushima Jong-Shi Pang

This paper is concerned with some feasibility issues in mathematical programs with equilibrium constraints (MPECs) where additional joint constraints are present that must be satis ed by the state and design variables of the problems. We introduce su cient conditions that guarantee the feasibility of these MPECs. It turns out that these conditions also guarantee the feasibility of the quadratic...

2014
Denis Tack Cynthia H. McCollough

When we chose Radiation Dose and Dose Reduction as the topic for the fifth volume in the Radiology Select series, we were very excited about offering a compilation of articles on a theme of utmost importance to all radiologists and health care providers. The concept of the right radiation dose for the right study, at the right time, is central to optimizing care for those patients who require i...

2016
Christopher L. Guy Elisabeth Weiss Nuzhat Jan Leonid B. Reshko Gary E. Christensen Geoffrey D. Hugo

PURPOSE To characterize mass and density changes of lung parenchyma in non-small cell lung cancer (NSCLC) patients following midtreatment resolution of atelectasis and to quantify the impact this large geometric change has on normal tissue dose. METHODS Baseline and midtreatment CT images and contours were obtained for 18 NSCLC patients with atelectasis. Patients were classified based on atel...

Journal: :Ultrasonics 1976
R L Johnston F Dunn

Histological preparations of ultrasonically produced lesions in cat brain, at 3 and 4 MHz, have been studied microscopically. The relationship of the delivered acoustic intensity at the lesion site, the energy absorbed per unit volume of the lesion, and the lesion volume is exhibited. It is suggested that universal responses to ultrasonic exposure may exist for different tissues.

Journal: :Journal of neurosurgery 2012
Jinyu Xue H Warren Goldman Jimm Grimm Tamara LaCouture Yan Chen Lesley Hughes Ellen Yorke

OBJECT Dose-volume data concerning the brainstem in stereotactic radiosurgery (SRS) for trigeminal neuralgia (TN) were analyzed in relation to associated complications. The authors present their set of data and compare it with currently cited information on brainstem dose tolerance associated with conventional fractionated radiation therapy and hypofractionated radiation treatment of other dise...

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