Introduction: In radiation therapy, accurate dose determination and precise dose delivery to the tumor are directly associated with better treatment outcomes in terms of higher tumor control and lower post radiation therapy complications. The current study aims the development and clinical application of the Patient Specific Quality Assurance (PSQA) procedures for nasopharyngea...

Background: In radiotherapy, low-energy photon beams are better adapted to the treated volume, and the use of high-energy beams can reduce hot spots in the radiation therapy. Therefore, mixing low and high energies with different ratios can control the rate of hotspots, as well as the dose distribution of the target volume.Material and Methods: The percentage depth doses (PDDs) were calculated ...

Introduction: The purpose of this work was to study the ability of MRI normoxic polymer gel dosimetry for evaluating the dose distribution in HDR brachytherapy of esophagial cancer at Imam Reza brachytherapy center (Mashhad, Iran). Materials and Methods: Initially, 2liters of normoxic gel (MAGIC) was fabricated and then poured into 12 calibration test tubes and placed in a perspex walled phanto...

This study presents the application of the Presage/optical-CT 3D dosimetry system for relative dosimetry in the Radiologic Physics Center (RPC) Head and Neck (H&N) IMRT phantom. Performance of the system was evaluated by comparison with the "gold-standard" RPC credentialing test. A modified Presage cylindrical insert was created that extended the capability of the RPC H&N phantom to 3D dosimetr...

Background: 3DCRT (three-dimensional conformal radiotherapy) and IMRT (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. However, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. The purpose of this study is to evaluate the imp...

Quantitative comparisons of dose distributions are an integral component of a medical physicist’s responsibility of assuring high quality radiation therapy dose delivery. While overlays and other displays of multiple dose distributions are useful for such evaluations, quantitative evaluations require a mathematical comparison. The dose-difference is the most straightforward method for comparing...

the effect of the fungus, metarhizium anisopliae, sub-lethal dose of imidacloprid, the aphid, myzus persicae and the three canola cultivars under microcosm conditions inside plastic cages in greenhouse (27 ± 3°c, rh 90 ± 5 %) indicated that field and semi-field concentrations of the fungus significantly reduced the population of green peach aphid (gpa) as well as in combination with lc10 of imi...