introduction: the aim of present study was to estimate effective dose from most common procedures performed in nuclear medicine departments of golestan province. methods: data of nuclear medicine procedures performed in 2 nuclear medicine departments in golestan province were collected during 4 years. effective dose, collective effective dose and effective dose per examination were calculated u...

background: in vivo dosimetry is a method for estimation of overall error in the delivered dose to the patients at the end of radiotherapy process. in this research, two methods for target dose calculation were evaluated on midline and central axis of photon beams in in vivo dosimetry of thorax fields. materials and methods: entrance and exit doses for anterior and lateral fields of thorax were...

Volumetric-modulated arc therapy (VMAT) plans may require more control points (or segments) than some of fixed-beam IMRT plans that are created with a limited number of segments. Increasing number of control points in a VMAT plan for a given prescription dose could create a large portion of the total number of segments with small number monitor units (MUs) per segment. The purpose of this study...

introduction: esophageal cancer is one of the most frequently occurring cancers in iran and having a  high  incidence  rate  among  other  countries.  radiotherapy  is  one  of  the  three  methods  (surgery,  radiotherapy and chemotherapy) for radical or palliative treatment of esophageal cancer. in this method  of treatment, the organs such as heart and spinal cord are regarded as organs at r...

introduction radiation exposures from diagnostic medical examinations are generally low and are almost always justified by the benefits of accurate diagnosis of possible disease conditions. therefore, entrance skin dose (esd), body organ dose (bod), and effective dose (ed) from adult patients undergoing routine thorax posterior-anterior (pa) and thorax right lateral (rlat) were estimated in uni...

PURPOSE To compare gamma knife treatment plans that use skull scaling instrument measurements for skull definition vs. CT based skull definition. METHODS Eight previously treated patients who had head CT scans were randomly selected. Their CT images were imported into Leksell GammaPlan. For each patient, three dose plans were developed: 1. the reference plan. It was planned based on the stand...

background: changes in body composition may be used for monitoring progression/ regression of a disease. prompt γ-rays in vivo neutron activation analysis (ivnaa) has been widely used for the measurement of body composition in recent years. objective: in this paper, we tried to improve the safety of ivnaa operator. methods: the most important factor for reducing the operator receiving dose is t...

PURPOSE New multidimensional dose comparison parameters, normalized agreement test (NAT) values and the NAT index, are introduced and compared with an ideal dose comparison parameter. In this article, we analyze a clinically based two-dimensional (2D) quantitative dose comparison case using a wide range of new and old comparison tools. In doing so, we address the benefits and limitations of man...

Introduction: One of the sources of natural occurring radiation was soils. The purpose of article was to determine soil pollution by radiation absorbed dose rate, radium equivalent activity, external hazard index, annual gonad dose equivalent and annual effective dose equivalent. Methods & Materials: The soil samples was located in Chahbahar city in Blouchestan of Iran, was chosen for studyin...

Introduction: This study was designed to evaluate dosimetric parameters such as rectal dose, bladder dose, integral dose (ID), homogeneity index (HI) and conformity index (CI) in various treatment plans for prostate cancer. Materials and Methods: Pelvic computed tomography (CT) scans of 27 patients were acquired and transferred to the RTDosePLAN treatment planning system. For each patient, 8 co...