This paper describes the algorithm and examines performance of an intensity-modulated radiation therapy (IMRT) beam-angle optimization (BAO) system. In this successive sets beam angles are selected from a set predefined directions using fast simulated annealing (FSA) algorithm. An IMRT beam-profile is performed on each generated beams. The accelerated by dose calculation method that utilizes precomputed kernel. A compact kernel constructed for beams prior to starting FSA optimizations during...

Currently, most intensity-modulated radiation therapy systems use dose–volume (DV)-based objectives. Although acceptable plans can be generated using these objectives, much trial and error is necessary to plan complex cases with many structures because numerous parameters need adjusted. An objective function that makes of a generalized equivalent uniform dose (gEUD) was developed recently has the advantage involving simple formulae fewer parameters. In addition, not only does gEUD-based...

We describe an approach for external beam radiotherapy of breast cancer that utilizes the three‐dimensional (3D) surface information breast. The data are obtained from a 3D optical camera is rigidly mounted on ceiling treatment vault. This light in visible range therefore it introduces no ionization radiation to patient. In addition topographical treated area, also captures gray‐scale overlaid image. allows us visualize skin markers and automatically determine isocenter position angles...

With intensity‐modulated radiotherapy (IMRT), a variety of user‐defined dose distribution can be produced using inverse planning. The generalized equivalent uniform (gEUD) has been used in IMRT optimization as an alternative objective function to the conventional dose‐volume‐based criteria. purpose this study was investigate effectiveness gEUD fine tune distributions plans. We analyzed effect gEUD‐based parameters on plan quality. determine whether selected structures could improved without...

Dose measurement for narrow stereotactic beams and intensity modulation radiotherapy beamlets is difficult error‐prone due to the lack of lateral electron equilibrium. A small detector position error finite sensitive volume as well nonfocus collimation could result in considerable (>10%) errors. new method introduced here measure dose components so that accuracy precision can be improved. Based on superposition principle, we create exactly field interest by subtraction a reference open...

This note describes a fast dose calculation method that can be used to speed up the optimization process in intensity-modulated radiotherapy (IMRT). Most iterative algorithms IMRT require large number of calculations achieve convergence and therefore total amount time needed for planning substantially reduced by using faster method. The is described this relies on an accurate engine calculate approximate kernel each beam treatment plan. Once computed saved, subsequent done rapidly looking...

Purpose. To report the characteristics of pancreas motion as tracked using implanted fiducials during radiotherapy treatments with CyberKnife. Methods and Materials . Twenty-nine patients cancer treated CyberKnife system were retrospectively selected for this study. During treatment, deviation is examined every 3-4 nodes (~45 s interval) compensated by robot. The displacement calculated from X-ray images acquired within time interval between two consecutive couch motions constitute a data...

Real-time stereovision-guidance has been introduced for efficient and convenient fractionated stereotactic radiotherapy (FSR) image-guided intensity-modulated radiation therapy (IMRT). This first pilot study is to clinically evaluate its accuracy precision as well impact on treatment doses. Sixty-one FSR patients wearing masks (SMs) nine IMRT flexible (FMs), were accrued. Daily target reposition was initially based-on biplane-radiographs then adjusted in six degrees of freedom under...

Traditional external beam radiotherapy of gynecological cancer consists a 3D, four‐field‐box technique. The radiation treatment area is large region normal tissue, with greater inhomogeneity over the volume, which could benefit more intensity‐modulated therapy (IMRT). This case report IMRT planning for patient endometrial cancer. target volume (PTV) spanned intrapelvic and periaortic lymph nodes to 33‐cm length. Planning were accomplished using double isocenters. plan was compared 3D plan,...

Two main approaches are commonly used in the literature for computing equivalent uniform dose (EUD) radiotherapy. The first approach is based on cell‐survival curve as defined linear‐quadratic model. second assumes that EUD can be computed generalized mean of distribution with an appropriate fitting parameter. We have analyzed connection between these two formalisms by deriving explicit formulas which applicable to normal distributions. From we established formalisms. found parameter has...

RF/Microwave Interaction with Biological Tissues Vander Vorst André Rosen Arye Kotsuka Youji. 330 pp., Wiley, Hoboken, NJ, 2006. $95.00. ISBN 0‐471‐73277‐X.

Purpose: The Novalis body system, ExacTrac®, was used to verify target localization and improve patient positioning for daily treatment with pre‐positioning by mask head frame in intensity modulated radio‐surgery(IMRS). This study is present preliminary results of quantitative measurements from the ExacTrac system. Method Materials: Accuracy image fusion correct calibration system were investigated using section anthropomorphic phantom. phantom randomly moved away position manually...

Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used monitoring this dose. We show operating a cell phone in the vicinity pocket dosimeter can introduce large and erroneous readings dosimeter. This note reports systematic study electromagnetic interference. found simple practical measures enough to mitigate problem, such as increasing distance between or shielding dosimeter, while...

Traditional external beam radiotherapy of gynecological cancer consists a 3D, four-field-box technique. The radiation treatment area is large region normal tissue, with greater inhomogeneity over the volume, which could benefit more intensity-modulated therapy (IMRT). This case report IMRT planning for patient endometrial cancer. target volume (PTV) spanned intrapelvic and periaortic lymph nodes to 33-cm length. Planning were accomplished using double isocenters. plan was compared 3D plan,...

Emerging Technologies in Medicine. Anastasio J., La Riviere P., Imaging Medical Diagnosis and Therapy, edited by William R. Hendee CRC, Boca Raton, FL, 2013. Price: $169.95. ISBN: 978‐1‐4398‐8041‐8, 361 pp. (hardcover).

Purpose: To report the characteristics of prostate motion as tracked using implanted fiducials during hypofractionated radiotherapy with CyberKnife. Method and Materials: Twenty one patients cancer who were treated CyberKnife between January 2005 September 2007 selected for this retrospective study. The uses a stereoscopic X‐ray system to obtain position target through monitoring gold fiducial markers. If there is significant deviation, treatment paused while patient repositioned by moving...

Objective: A CyberKnife G4 system (Accuray Inc.) went clinical at our cancer center on Oct. 17, 2006. The platform is built a 6 MV X‐band linear accelerator mounted multi‐jointed manipulator with 600 MU/min dose rate, 50% higher than the G3 system. also features flush‐mounted, in‐floor x‐ray image detectors, providing an increase in treatment workspace and expanding potential for extra‐cranial applications. Our experience its comparison to will be presented here. Methods: In two half months...

Objective: A CyberKnife G4 system was installed at SUMC in September 2006. Unique challenges involved the commissioning process of this such as determination kQ for absolute calibration, direct TPR measurement, output factor measurements small collimators, and radiation dose verification are discussed. Comparisons made between newer older G3 which also recently recommissioned part an upgrade. Methods: An anthropomorphic head phantom used testing four different available tracking modes. All...

Purpose: The three-source model proposed by Yang et al.1 when applied to Siemens PRIMUS 6 MV beam over-estimated head scatter 10–200% for field sizes less than 2 cm × and elongated narrow beams. This necessitated the development of a modified approach Method Materials: complete theoretical background can be found in published literature1 which total energy fluence at point calculation divided into three components. primary component Cp has been chosen around 90% model. A is with source...