An EGS Monte Carlo model for Varian TrueBEAM treatment units: Commissioning and experimental validation of source parameters.

In this work we have created and commissioned a Monte Carlo model of 6FFF Varian TrueBeam linear accelerator using BEAMnrc. For this purpose we have experimentally measured the focal spot size and shape of three Varian TrueBeam treatment units in 6FFF modality with a slit collimator and several depth dose and lateral beam profiles in a water phantom. The Monte Carlo model of a 6FFF TrueBeam machine was implemented with a primary electron source commissioned as a 2D Gaussian with Full Width Half Maximum selected by comparison of simulated and measured narrow beam profiles.

Development and clinical characterization of a novel 2041 liquid-filled ionization chambers array for high-resolution verification of radiotherapy treatments.

Purpose: The aim of this study was to present a novel 2041 liquid-filled ionization chamber array for high-resolution verification of radiotherapy treatments.

Materials And Methods: The prototype has 2041 ionization chambers of 2.5 × 2.

Correction for FDG PET dose extravasations: Monte Carlo validation and quantitative evaluation of patient studies.

Purpose: Current procedure guidelines for whole body [18F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) state that studies with visible dose extravasations should be rejected for quantification protocols. Our work is focused on the development and validation of methods for estimating extravasated doses in order to correct standard uptake value (SUV) values for this effect in clinical routine.

Methods: One thousand three hundred sixty-seven consecutive whole body FDG-PET studies were visually inspected looking for extravasation cases.

A convolution model for obtaining the response of an ionization chamber in static non standard fields.

Purpose: This work contains an alternative methodology for obtaining correction factors for ionization chamber (IC) dosimetry of small fields and composite fields such as IMRT. The method is based on the convolution/superposition (C/S) of an IC response function (RF) with the dose distribution in a certain plane which includes chamber position. This method is an alternative to the full Monte Carlo (MC) approach that has been used previously by many authors for the same objective.