Introduction Stereotactic radiosurgery (SRS) has been increasingly advocated for 1-3 small brain metastases. The goal of this study was to evaluate the clinical results in patients with brain metastases treated with LINAC-based SRS using a thermoplastic mask (non-invasive fixation system) and Image-Guided Radiotherapy (IGRT). Material and Methods In this single-institution study 48 patients w...

ID: 9678 Title: An analytical approach to prevent gantry-couch collision for linac-based radiosurgery Gantry-couch collision is a serious concern for the treatment planning of the linac-based stereotactic radiosurgery (SRS). The ability to detect collision at the planning time removes the need for backup plans and preserves the useful beam angles that would be deemed unsafe and discarded otherw...

Volumetric-modulated arc therapy (VMAT) is a widespread intensity-modulated radiation therapy (IMRT) method, however, VMAT requires adaptation of the radiation treatment planning system (RTPS) and linear accelerator (linac); these upgrades are quite expensive. The Smart Arc of Pinnacle(3) (Philips), which is the software used in VMAT calculations, can select constant dose rate (CDR) mode. This ...

Normalize the response of electronic portal imaging device (EPID) is the first step toward an EPID-based standardization of Linear Accelerator (linac) dosimetry quality assurance. In this study, we described an approach to generate two-dimensional (2D) pixel sensitivity maps (PSM) for EPIDs response normalization utilizing an alternative beam and dark-field (ABDF) image acquisition technique an...

 Introduction: Monte Carlo method is often applied in radiation therapy as utilized in all the branches of science. An important requirement for successful radiotherapy is carefully examine the dose distribution specifications and decrease the difference between these features with experience to an acceptable level. In this study, the characteristics of 6, 15 and 20 MeV incident x-rays are prov...

To calculate the risk of secondary cancer induction resulting from this dose through a Monte Carlo simulation code and voxel-based anthropomorphic phantom to determine radiation in organs and/or tissues with dosimetric importance effect using static MLC 3D-CRT technique. In work, radiotherapy treatment breast was simulated transport MCNPX 2.7.0 adult simulator FSTA_H50_M50. The absorbed doses f...

Abstract Introduction: Recent studies have shown that the use of high-density nanoparticles (NPs) in concrete composition improves its radiation shielding properties. In present study, linear attenuation coefficients and photon scattering properties newly developed Nano-concretes been calculated using MCNPX Monte Carlo code. Material methods: The containing 10%, 20%, 30% weight percentage Osmiu...

The purpose of the present study was to use a kilovoltage imaging device to measure interfractional and intrafractional setup deviations in patients with head-and-neck or brain cancers receiving intensity-modulated radiotherapy (IMRT) treatment. Before and after IMRT treatment, approximately 3 times weekly, 7 patients were imaged using the Varian On-Board Imager (OBI: Varian Medical Systems, Pa...

Varian Halcyon 2.0 linear accelerator was launched and became available for clinical use in 2018. Therefore, it is necessary to evaluate the accuracy of exit fluence quality assurance (QA) head neck cancer treatment planning, pretreatment, treatment. The twenty plannings has been evaluated by conducting gamma analysis QA pretreatment each field composite using criteria index 3 %/3 mm 2 %/2 mm. ...

Several algorithms exist to perform quality assurance for volumetric-modulated arc therapy (VMAT) treatments based on electronic portal imaging devices (EPID). These algorithms are used to compare doses (convert into water, GLAaS) and fluences (in amorphous silicon (aSi), Varian portal dosimetry). The aim of this study is to compare the two methods using clinical data. In this study, Varian por...