Accurate treatment planning in radiotherapy essentially decreases damage to healthy tissue surrounding the tumor. Due plans use a direct, highly collimated, narrow beam with high intensity treat small area tumors, researchers have studied microbeam radiation therapy extensively. Using synchrotron as source may help limit damage, but using computerized simulations and dosimetry is still necessar...

ALLEGRO is an European project investigating health risks following radiotherapy. In this frame our group has performed out-of-field dose measurements to compare different types of radiation therapy, studying the influence of the delivery technique and the beamline structure on the dose profile. The data obtained can be used as validation of Monte Carlo models and for assessing the risk of deve...

The term of brachytherapy, also known as “internal radiotherapy, sealed source radiotherapy, curietherapy or endocurietherapy” is from Greek work brachy means short distance and therapy (treatment) and also known as internal radiotherapy or sealed source radiotherapy. Brachytherapy is a special form of radiotherapy where a radioactive source is carefully placed on or inside the area to be treat...

Introduction: Penumbra is an important property of the radiation beam to obtain a suitable margin surrounding the target volume. Therefore, the precise penumbra width determination in stereotactic radiotherapy is necessary for treatment planning. This study aimed to compare the obtained results of penumbra width by in-house and standard circul...

Background: Two protocols of AAPM TG-51 and IAEA TRS-398 were compared followed by a measurement and Monte Carlo simulation of beam quality correction factor, KQ, AAPM TG-51 and IAEA TRS-398 protocols were compared for the absorbed dose to water for DW, and KQ parameters. Materials and Methods: Dose measurements by either protocols were performed with cylindrical and plane parallel ch...

The problem of demixing in the Asakura-Oosawa colloid-polymer model is considered. The critical constants are computed using truncated virial expansions up to fifth order. While the exact analytical results for the second and third virial coefficients are known for any size ratio, analytical results for the fourth virial coefficient are provided here, and fifth virial coefficients are obtained ...

Single-chain Monte Carlo simulations were carried out, in continuous space, of polymers with various topologies (branched and linear) in the good solvent. Using an inherently flexible beadand-spring model, the backbone of linear polymers with either linear or dendritic side-groups attached was found to be elongated, indicative of an induced stiffness. This “topological stiffness” was compared t...

We report Monte Carlo simulations of the melting of a singlepolymer crystallite. We find that, unlike most atomic and molecular crystals, such crystallites can be heated appreciably above their melting temperature before they transform to the disordered ”coil” state. The surface of the superheated crystallite is found to be disordered. The thickness of the disordered layer increases with superh...

Abstract: Local stiffness of polymer chains is instrumental in all structure formation processes of polymers, from crystallization of synthetic polymers to protein folding and DNA compactification. We present Stochastic Approximation Monte Carlo simulations—a type of flat-histogram Monte Carlo method—determining the density of states of a model class of single semi-flexible polymer chains, and,...