A description is given of the UK primary standard graphite calorimeter system. The calorimeter measures absorbed dose to graphite for photon radiations from 60Co to 19 MV x-rays, and is the basis of the NPL therapy-level absorbed dose to water calibration service. Absorbed dose to graphite from the photon calorimeter has been compared with three other standards: an ionization chamber and cavity...

Large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. Therefore, radiation unwanted dose is created in kidney. As a result, exact calculation of prescribed radiopharmaceuticals amount is important. Monte Carlo method is used for simulation of radiation transport in body due to random nature of radiation. In this research, for the first time...

The IAEA Code of Practice for Absorbed Dose Determination in Photon and Electron Beams TRS 277 gives recommendations for the absorbed dose determination in high energy photon and electron beams based on the use of ionization chambers calibrated in terms of air kerma. It was the task of the present work to test the validity of the Code for *°Co gamma radiation for ton different types of ionizati...

The main detectors used for clinical dosimetry are ionisation chambers and semiconductors. Thermoluminescent (TL) dosimeters are also of interest because of their following advantages: i) wide useful dose range, ii) small physical size, iii) no need for high voltage or cables, i.e. stand alone character, and iv) tissue equivalence (LiF) for most radiation types. TL detectors can particularly be...

The feasibility of disrupting a tumor's vascular structure with various radiation types and radionuclides is investigated. Calculated absorbed dose profiles for photons and (4)He ions suggest that low-energy beta-gamma and alpha emitting radionuclides can deposit sufficient absorbed dose to disrupt a tumor's vascular structure while minimizing the dose outside the blood vessel. Candidate radion...

Background: Results are presented on some dosimetric characteristics of Sife – Eldeen dosimeter based on the radiation induced conductivity (RIC) of 3.5 M aqueous urea solutions. The studied characteristics were the response (RIC) of Sife – Eldeen dosimeter in broad ranges of absorbed dose, dose rates and at different irradiation temperature. Materials and Methods: Kent EIL5007 conductivity met...

background: the shielding methods in radiotherapy due to delivering an accurate radiation dose to cancer tissues and avoiding unnecessary dose to normal tissues are very important. these methods include lead standard blocks, individual molding and multi leaf collimator (mlc). the mlc method is not still common in iran radiotherapy centers. individual molding is better than the lead block shield...

introduction in computed tomography (ct) technology, an optimal radiation dose can be achieved via changing radiation parameters such as ma, pitch factor, rotation time and tube voltage (kvp) for diagnostic images. materials and methods in this study, the brain, abdomen, and thorax scaning was performed using toshiba 16-slice scannerand standard aapm and ctdi phantoms. aapm phantom was used for...