Introduction The use of cut-outs in electron applicators make changes on output, isodose, and percentage depth dose (PDD) curves. These changes and electron beam dose distribution in the form of three-dimensional (3D) can be measured by gel dosimeters. Materials and Methods Dosimetry was performed with and without a square shield (6×6 cm2 field). The energies were 4, 9, and 16 MeV and phantom w...

introduction:  skin  sparing  is  one  of  the  most  desirable  characteristics  of  high  energy  photon  beams. however, the photons emerging from the target of linacs are contaminated by secondary  electrons  as  a  result  of  their  interactions  with  air,  collimators,  flattening  filter  and  any  other  objects in their path. this phenomenon tends to increase the skin dose received b...

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...

Introduction: Multiple fields and presence of heterogeneities create complex dose distributions that need three dimensional dosimetry. In this work, we investigated MR-based MAGIC gel dosimetry as a three-dimensional dosimetry technique to measure the delivered dose to bladder and rectum in prostate radiation therapy. Materials and Methods: A heterogeneous slab phantom including bones was made....

Background: Gold nanoparticles (GNPs) have been shown as a good radiosensitizer. In combination with radiotherapy, several studies with orthovoltage X-rays have shown considerable dose enhancement effects. This paper reports the dose enhancement factor (DEF) due to GNPs in 18 megavoltage (MV) beams. Materials and Methods: Different geometrical 50-nm GNPs configurations at a concentrati...

background: recently, different investigators have studied the possibility of radiation therapy in restenosis prevention and have shown promising results. in this study a unique radioactive source for intra vascular brachytherapy (ivbt) was investigated. the two-dimensional dose distribution in water for a 32p ivbt stent has been calculated. the pure beta emitter source 32p has been coated on p...

Introduction Low dose rate brachytherapy sources have been widely used for interstitial implants in tumor sites, particularly in prostate. Dosimetric characteristics of a new IrSeed 125I brachytherapy source have been determined using the LiF thermoluminescent dosimeter (TLD) chips. Materials and Methods Dose rate constant, radial dose function, and anisotropy function around the IrSeed 125I so...

Introduction: Although there are several ways to relief pain in metastatic patients, the use of radionuclides is one of the known and effective ways to relieve the pain caused by bone metastases. The purpose of this study was to assessment of radiation dose distribution of different radioisotopes used to treatment and pain relief patients in a bone-based model based on Monte C...

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, ...