An electronic portal image device (EPID) has become a method of patient-specific IMRT dose verification for radiotherapy. Research studies have focused on pre and post-treatment verification, however, there are currently no interventional procedures using EPID dosimetry that measure the dose in real time as a mechanism to ensure that overdoses do not occur and underdoses are detected as soon as...

Introduction: Electronic Portal Imaging Device (EPID) and Cone Beam Computed Tomography (CBCT) are the preferred tools of Image Guided Radiotherapy (IGRT) and Dose Guided Radiotherapy (DGRT) which have been used for Radiotherapy treatment verifications. As a result, the number of publications dealing with these two tools for radiation treatment verification has increased consi...

Background: In order to assign appropriate planning target volume (PTV) margins, each centre should measure the patient positioning deviations for their set-up techniques. At the Royal Marsden Hospital, UK, a conformal shell (cast) system is used when a stereotactic frame is not suitable. In this paper, we report on a series of measurements with the aim of obtaining the systematic and random ...

Limiting factors for the precise orbit determination POD of low-earth orbit LEO satellite using dual-frequency GPS are nowadays mainly encountered with the in-flight phase error modeling. The phase error is modeled as a systematic and a random component each depending on the direction of GPS signal reception. The systematic part and standard deviation of random part in phase error model are, re...

background: in order to assign appropriate planning target volume (ptv) margins, each centre should measure the patient positioning deviations for their set-up techniques. at the royal marsden hospital, uk, a conformal shell (cast) system is used when a stereotactic frame is not suitable. in this paper, we report on a series of measurements with the aim of obtaining the systematic and random co...

It is well known that measurement error of numerical measurements can be divided into a systematic and a random component and that only the latter component is estimable if there is no gold standard or reference standard available. In this paper, we consider measurement error of nominal measurements. We motivate that, on a nominal measurement scale too, measurement error has a systematic and a ...

This study evaluated the agreement of fiducial marker localization between two modalities--an electronic portal imaging device (EPID) and cone-beam computed tomography (CBCT)--using a low-dose, half-rotation scanning protocol. Twenty-five prostate cancer patients with implanted fiducial markers were enrolled. Before each daily treatment, EPID and half-rotation CBCT images were acquired. Transla...