AbstractIntroduction Silicone gel breast implants are used for breast reconstruction post mastectomy. In the event of cancer recurrence, the radiation oncologists are forced to irradiate through the prosthesis device. Due to prosthesis higher atomic number dose perturbations occur during treatment. This study determined the influence of silicone gel thickness on the photon beam distribution. Ma...

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:  on  the  basis  of  percent  depth  dose  (pdd)  calculation,  the  application  of  dosimetry  in  radiotherapy  has  an  important  role  to  play  in  reducing  the  chance  of  tumor  recurrence. the aim of this study is to introduce a new formula for calculating the centeral axis  percent depth doses of cobalt-60 beam.   materials and methods: in the present study, based on ...

The percentage depth dose in the build-up region and the surface dose for the 6-MV photon beam from a Varian Clinac 23EX medical linear accelerator was investigated for square field sizes of 5 × 5, 10 × 10, 15 × 15 and 20 × 20 cm(2)using the EGS4nrc Monte Carlo (MC) simulation package. The depth dose was found to change rapidly in the build-up region, and the percentage surface dose increased p...

Introduction: Many studies have shown the effects of delivered dose distribution due to the incident photon energy on the tumor and healthy tissues. The ability to access the most appropriate radiation energy is essential to achieve the optimal treatment planning but there is a serious limitation in number of energies available on radiation therapy machines can restrict it. <s...

Background: The purpose of this study was to determine the percentage depth dose (PDD) of PAGAT normoxic polymer gel dosimeter by electron beams using MRI technique for a standard clinically used Co-60 therapy unit and an electa linear accelerator. Materials and Methods: Using MRI, the formulation to give the maximum change in the transverse relaxation rate R2(1/T2) was determined to be 4.5% N,...