Background: The anatomic position and proven radiosensitivity of the thyroid make it an organ of concern in dental X-ray examinations. A National Radiation Protection Department (NRPD)-sponsored pilot study carried out in the Dental Radiology Department of RUMS., to assess if the radiation dose in panoramic radiographies could be reduced without significant impairment of the subjective image qu...

Background: During intensity modulated radiation therapy (IMRT) technique, theoretically, presence of flattening filter (FF) across the beamline of clinical linear accelerator (linac) is not essential to obtain uniform lateral profiles due to intensity modulation of photon beams by multileaf collimators (MLCs). The aim of this study was to investigate the dosimetrical properties of 18 MV photon...

Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

PURPOSE A cylinder applicator is the standard treatment device for intravaginal brachytherapy. However, they are limited in their ability to simultaneously spare the organs at risk (OAR), and reduce the hot spot in the vaginal mucosa, while achieving adequate dose conformality. This study aims to compare the dosimetric characteristics of single and multi-channel cylinders, and utilizes volume p...

introduction: coronary angiography and angioplasty procedures lead to significant radiation exposure of patients. in the current study, the average radiation dose to patients during angiography in the angiography department of shahid-madani hospital was determined. materials and methods: an image intensifier based angiography unit (philips bh 3000) was used for angiography procedures. the accur...

introduction: in 2000, the unscear reported that ct constitutes 5% of all the medical x-ray  examinations and it contributes 34% of the resultant collective dose worldwide. children are more  sensitive to the ionizing radiations than adults. so, routine quality control tests are expected to be  carried out periodically on the ct scanners. the aim of this research was to estimate the effective  ...

background: the aim of the study was to analyze the effective dose record of occupationally exposed radiation workers at bahawalpur institute of nuclear medicine and oncology department. materials and methods: annual effective doses of occupationally exposed workers were measured by film badge dosimetry by sending the dosimeters to radiation dosimetry laboratory (rdl), pakistan institute of nuc...

a lithium borate thermoluminescence dosimeter with 0.3 wt% of manganese impurityconcentration was prepared for high dose levels in the range of 1-30 kgy for gamma irradiation applications.the tld reader was used for read out purposes from ambient temperature to about 400°c with a heating rate of 6°c/sec. the pre- and post- irradiation anneal temperature was 300°c for 1.5 and 1 hours respectivel...

Introduction The present work describes a study in which, based on patient dose measurements, thermoluminescent dosimeters were used to obtain the diagnostic reference level arising from panoramic radiography. Materials and Methods Ten panoramic units and a sample of 15 patients per X-ray unit were studied. Two thermoluminescent dosimeter chips were placed on the skin surface of selected organs...

PURPOSE The goal of this work was to evaluate measured vs. calculated surface dose as a function of PTV-to-skin proximity and calculation matrix oxel size, determine effects on plan quality, and provide parameters and levels of uncertainty for clinical use. METHODS A right-sided CTV with the lateral border 5mm from the surface was delineated on the CT data of a head and neck phantom. A 5mm PT...