The effect of dose calculation accuracy during inverse treatment planning for intensity modulated radiotherapy (IMRT) was studied in this work. Three dose calculation methods were compared: Monte Carlo, superposition and pencil beam. These algorithms were used to calculate beamlets. which were subsequently used by a simulated annealing algorithm to determine beamlet weights which comprised the ...

We consider a Fermi pencil beam model in two space dimensions (x; y), where x is aligned with the beam's penetration direction and y together with the scaled angular variable z, correspond to a bounded symmetric , transversal cross section. We study some fully discrete numerical schemes using the standard Galerkin and streamline diiusion nite element methods for discretization of the transversa...

Conically scanning pencil-beam scatterometer systems, such as the recently launched SeaWinds radar, constitute an important class of instruments for spaceborne climate observation. In addition to ocean winds, scatterometer data are being applied to a wide range of land and cryospheric applications. A key issue for future scatterometer missions is improved spatial resolution. Pencil-beam scatter...

This study compares Monte Carlo (MC) with conventional treatment planning system (TPS) calculations. The EGS4nrc MC code, BEAMnrc, was commissioned to simulate a Varian 21Ex Linac. The accuracy of the simulations, including points blocked by the jaws, was evaluated by comparing MC with ion chamber and MOSFET measurements. Eight mesothelioma IMRT cases were planned using Eclipse (pencil beam and...

Pencil Beam Scanning is a dynamic beam delivery system developed for proton therapy. The radiation field necessary to reach in a fast and robust way a prescribed 3D dose distribution is obtained by accurately controlling both the extraction of the beam from a 235 MeV accelerator and the motion of the beam spot thanks to scanning magnets. This paper focuses on the trajectory planning aspect of t...

The high density and atomic number of hip prostheses for patients undergoing pelvic radiotherapy challenge our ability to accurately calculate dose. A new clinical dose calculation algorithm, Monte Carlo, will allow accurate calculation of the radiation transport both within and beyond hip prostheses. The aim of this research was to investigate, for both phantom and patient geometries, the capa...

Purpose: The purpose of this work is to study and quantify the differences in calculated dose computed with two algorithms available in treatment planning systems: Pencil Beam Convolution and Clarkson. Material and Methods: Four different types of treatment cases were analyzed: lung, head and neck, brain and prostate. For each case, the volume definition was based on a clinical CT-scan acquisit...

The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system's behavior in simple geometries and in configurations encountered in clinical practice. The first series of t...