Introduction: Computerized treatment planning is a rapidly evolving modality that depends on hardware and software efficiency. Despite ICRU recommendations suggesting 5% deviation in dose delivery the overall uncertainty shall be less than 3.5% as suggested by B.J. Minjnheer. J. In house spreadsheets are developed by the medical physicists to cross-verify the dose calculated by the Treatment Pl...

background: radiotherapy treatment planning requires different dosimetric quantities as input in order to calculate a desired dose distribution. this study has been focused to evaluate the depth dose characteristics of superficial x-rays being used for radiotherapy treatment. materials and methods: computerized 3-d water phantom of multi-data system was used. the measurements were made through ...

Introduction: Metal prostheses in patients affect the radiotherapy dose distribution. Metal prostheses with high density and atomic number cause major changes in scattering and attenuation of radiation. The present study aims to assess the impact of metal knee prosthesis with various dimensions and materials on radiotherapy dose distribution. Material and Methods: In this research, the Varian L...

Introduction: The utilization of high-energy photons in the medical linear accelerator can lead to photoneutron production. This study aimed to evaluate the effect of the physical components of the head, including flattening filter (FF) andmultileaf collimator (MLC), as well as the dependence of therapeutic field size on the photoneutron spectrum, dose, and flux. <str...

PURPOSE Flattening filter free (FFF) beams in radiotherapy have advantages such as shorter treatment delivery time and lower out-of-field dose compared with conventional flattened beams. This study investigates in detail the skin dose induced by FFF beams from a TrueBeam accelerator (Varian Medical Systems, Palo Alto, CA) using Monte Carlo method. METHODS Phase space files generated using rea...

Introduction: Skin dose and depth dose distribution of some beta sources that can contaminate skin or protective clothing covering the skin have been calculated using VARSKIN2. Materials and Methods: In this research, absorbed dose to skin and depth dose from the skin surface have been calculated for 90Sr/90Y, 147Pm, 32P beta emitter radioisotopes by using input parameters: activity of source, ...

Introduction: Radiation therapy using electron beams is a promising method due to its physical dose distribution. Monte Carlo (MC) code is the best and most accurate technique for forespeaking the distribution of dose in radiation treatment of patients.Materials and Methods: We report an MC simulation of a linac head and depth dose on central axis, along with profile calculations. The purpose o...

Background: Radiosurgery is a focal brain irradiation technique that delivers, usually in a single session, high dose of ionizing radiation. The presence of lateral electronic disequilibrium and steep dose gradients in small fields demands special attention to the selection of a suitable detector with respect to its size, composition and response. Materials and Methods : Small circular fields w...

introduction: using beta emitter radionuclide is a useful therapeutic modality in the treatment of skin cancers in areas which are difficult to cure by other methods. the aim of this research is to evaluate the tissue response to beta rays of 166ho and determine the feasibility of beta emitting radionuclide for treatment of skin cancers. methods: in this work, we have calculated depth dose dist...