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PURPOSE We present a validation study of CT and PET lung image registration and fusion based on the chamfer-matching method. METHODS AND MATERIALS The contours of the lung surfaces from CT and PET transmission images were automatically segmented by the thresholding technique. The chamfer-matching technique was then used to register the extracted lung(More)
LIGHTNING is a dynamically reconfigurable WDM network testbed project for supercomputer interconnection. This paper describes a hierarchical WDM-based optical network testbed that is being constructed to interconnect a large number of supercomputers and create a distributed shared memory environment. The objective of the hierarchical architecture is to(More)
A plot of a cumulative dose-volume frequency distribution, commonly known as a dose-volume histogram (DVH), graphically summarizes the simulated radiation distribution within a volume of interest of a patient which would result from a proposed radiation treatment plan. DVHs show promise as tools for comparing rival treatment plans for a specific patient by(More)
The radiation treatment with catheter-based beta-emitter sources is under clinical trials to prevent restenosis following interventional coronary procedures. There are still large uncertainties in the dose calculation due to the complicated treatment geometry. We present the Monte Carlo simulations to account for the dosimetric perturbations due to(More)
PURPOSE Contralateral breast dose from primary breast irradiation has been implicated in the risk of second breast malignancies. It has been previously shown that the use of half-beam blocking can increase the opposite breast dose by a factor of five. This study evaluates four different breast treatment techniques to compare the radiation dose to the(More)
The ability to improve existing standards of treating prostate cancer was investigated. To deliver a homogenous dose to the prostate with as little normal tissue margin as practical, seven patients with low volume carcinoma of the prostate were immobilized with alpha cradle body casts prior to using a CT-based 3D treatment planning system and beam's eye(More)
Three-dimensional treatment planning for the intact breast was performed on two patients who had undergone CT scanning. A total of 38 treatment plans were evaluated. Multiple plans were evaluated for each patient including plans with and without inhomogeneity corrections, plans using varying photon energies of 60Co, 4 MV, 6 MV, 10 MV, and 15 MV, and(More)
PURPOSE To study the variation of computed tomography (CT) number from a simulator-based scanner and the effect of this variation on photon-dose calculations. METHOD AND MATERIALS CT images of a cylindrical phantom with multiple inserts were obtained using a commercially-available simulator-CT (Ximatron: Varian, Palo Alto, CA). The linear correlation(More)
The purpose of this work is to calculate the head scatter factors for any arbitrary jaw setting by using two different semi-empirical methods. The head scatter factor at the center of field (COF) for any arbitrary jaw setting can be defined as H(COF)(X1,X2,Y1,Y2,r)=DairCOF(XI1,X2,Y1,Y2,r)/ [Dair(5,5,5,5,0)*OAR(r)], where X1, X2, Y1, and Y2 are the jaw(More)
The purpose of this study is to analyze the characteristics of dynamic wedges (DW) and to compare DW to physical wedges (PW) in terms of their differences in affecting beam spectra, energy fluence, angular distribution, contaminated electrons, and dose distributions. The EGS4/BEAM Monte Carlo codes were used to simulate the exact geometry of a 6 MV beam and(More)