The calcium-sensing receptor (CaR) has an essential role in mediating Ca(2+)-induced keratinocyte differentiation in vitro. In this study, we generated keratinocyte-specific CaR knockout ((Epid)CaR(-/-)) mice to investigate the function of the CaR in epidermal development in vivo. (Epid)CaR(-/-) mice exhibited a delay in permeability barrier formation during embryonic development. Ion capture c...

AIM The aim of the study was to estimate the dose at the reference point applying an aSi-EPID device in the course of patient treatment. MATERIALS AND METHODS The method assumes direct proportionality between EPID signal and dose delivered to the patient reference point during the treatment session. The procedure consists of treatment plan calculation for the actual patient in the arc techniq...

THE SEVEN books of Epidemics ("Epidemiae": visits to cities) which come to us in the Hippocratic Corpus fall into three groups, Epid. I and 3, Epid. 2, 4, and 6, and Epid. 5 and 7. Like the other works of the Corpus, their authorship, provenance, and dates are in doubt.' Traditionally since Galen's time Epid. I and 3 have been admired as Hippocrates' work or as the work of a "Coan" school conne...

This study focused on predicting the electronic portal imaging device (EPID) image of intensity modulated radiation treatment (IMRT) fields in the absence of attenuation material in the beam with Monte Carlo methods. As IMRT treatments consist of a series of segments of various sizes that are not always delivered on the central axis, large spectral variations may be observed between the segment...

PURPOSE To investigate the long term stability and viability of using EPID-based daily output QA via in-house and vendor driven protocol, to replace conventional QA tools and improve QA efficiency. METHODS Two Varian TrueBeam machines (TB1&TB2) equipped with electronic portal imaging devices (EPID) were employed in this study. Both machines were calibrated per TG-51 and used clinically since ...

abstract background: for treatment verification in radiation therapy. several physical characteristics of scanningliquid filled ionization chamber epid (slic-epid) including: extra build-up layer,reproducibility and uniformity, and noise level were investigated.electronic portal imaging devices (epids) have found an outstanding positionmaterials and methods: equilibrium, 1-30 mm white water mat...

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...

AIMS This study investigates the impact of cine acquisition mode on the dosimetric characteristics of a Varian aS500 amorphous silicon electronic portal imaging device (a-Si EPID). MATERIALS AND METHODS The performance of an a-Si EPID operated in cine mode was assessed and compared to its performance when operated in an integrated mode and dose measurements using an ionization chamber. This s...

Introduction: Electronic portal imaging devices (EPIDs) could potentially be useful for intensity-modulated radiation therapy (IMRT) and VMAT QA. The data density, high resolution, large active area, and efficiency of the MV EPID make it an attractive option. However, EPIDs were designed as imaging devices, not dosimeters, and as a result they do not inherently measure dose in ...

Electronic portal imaging devices (EPIDs) were originally developed for the purpose of patient setup verification. Nowadays, they are increasingly used as dosimeters (e.g., for IMRT verification and linac-specific QA). A prerequisite for any clinical dosimetric application is a detailed understanding of the detector's dose-response behavior. The aim of this study is to investigate the dosimetri...