background: monte carlo (mc) modeling of a linear accelerator is a prerequisite for monte carlo dose calculations in external beam radiotherapy. in this study, a simple and efficient model was developed for elekta sl-25 linear accelerator using mcnp4c monte carlo code materials and methods: the head of elekta sl-25 linac was simulated for 6 and 18 mv photon beams using mcnp4c mc code. energy sp...

Background: The aim of this study was to develop and implement a Monte Carlo framework for evaluation of patient specific out-of-field organ equivalent dose (OED). Materials and Methods: Dose calculations were performed using a Monte Carlo-based model of Oncor linac and tomographic phantoms. Monte Carlo simulations were performed using EGSnrc user codes. Dose measurements were performed using r...

Background: An effective method for management of large and bulky malignant tumors. This treatment modality is also known as Specially Fractionated Radiation Therapy (SFRT). In this treatment technique a grid block converted the open radiation field into a series of pencil beams. Dosimetric characteristics of an external beam grid radiation field have been investigated using experimental and Mo...

background: an effective method for management of large and bulky malignant tumors. this treatment modality is also known as specially fractionated radiation therapy (sfrt). in this treatment technique a grid block converted the open radiation field into a series of pencil beams. dosimetric characteristics of an external beam grid radiation field have been investigated using experimental and mo...

We study optimal stochastic (or Monte Carlo) quadrature formulas for convex functions. While nonadaptive Monte Carlo methods are not better than deterministic methods we prove that adaptive Monte Carlo methods are much better. Abstract. We study optimal stochastic (or Monte Carlo) quadrature formulas for convex functions. While nonadaptive Monte Carlo methods are not better than deter-ministic ...

we compare two approaches for a markovian model in flexible manufacturing systems (fmss) using monte carlo simulation. the model which is a development of fazlollahtabar and saidi-mehrabad (2013), considers two features of automated flexible manufacturing systems equipped with automated guided vehicle (agv) namely, the reliability of machines and the reliability of agvs in a multiple agv jobsho...

introduction: there are several technical features that make pet an ideal device for the noninvasive evaluation of cardiac physiology. organ motion due to respiration is a major challenge in diagnostic imaging, especially in cardiac pet imaging. these motions reduce image quality by spreading the radiotracer activity over an increased volume, distorting apparent lesion size and shape and reduci...

background: high-energy linear accelerator (linac) is a valuable tool and the most commonly device for external beam radiation treatments in cancer patients. in the linac head, high-energy photons with energies above the threshold of interaction produce photoneutrons. these photoneutrons deliver the extra dose to the patients in the planning treatment and increase the risk of secondary cancer. ...

background: stereotactic radiosurgery is an important clinical tool for the treatment of small lesions in the brain, including benign conditions, malignant and localized metastatic tumors. a dosimetry study was performed for elekta ‘synergy s ’ as a dedicated stereotactic radiosurgery unit, capable of generating circular radiation fields with diameters of 1-5 cm at isocentre using the beam/egs4...