background : medical x-rays are the largest man-made source of public exposure to ionizing radiation. while the benefits of computed tomography (ct) are well known in accurate diagnosis, those benefits are not risk-free. ct is a device with higher patient dose in comparison with other conventional radiation procedures. objective: this study is aimed at evaluating radiation dose to patients from...

background: to evaluate the dosimetric difference between conventional and three-dimensional conformal radiotherapy (3d-crt) using 6 and 18 mv x-ray photons. materials and methods: computed tomography scans of 26 pelvic patients were acquired and transferred to the 3d treatment planning system. for each patient, 8 conventional plans (3, 4, 5 and 6 fields) and one 3d-crt plan were prepared using...

background: atherosclerosis, a chronic inflammatory disease of the vessel wall is characterized by local and systemic immune responses to a variety of antigens. oxidized low-density lipoprotein (oxldl) is considered as an important determining factor in the pathogenesis of atherosclerosis. objective: the purpose of this study was to investigate the degree of peripheral blood mononuclear cells (...

background: although some patients can tolerate colonoscopy procedure using fentanyl/ midazolam without any sedation and analgesic requirements but some patients may require additional sedation with benzodiazepines. we performed the present study to compare the effect of paracetamol/midazolam with fentanyl/ midazolam. methods: in a clinical trial, 96 patients aged 18 to 75 years old, who were c...

background: application of dose-area product (dap) quantity has been increased in the clinical practice. dap is relatively easy to measure. dap has been shown to correlate well with the total energy imparted to the patient, which is related to the effective dose. material and methods: in this study, measurements of dap were carried out in a sample of 421 adult patients who underwent conventiona...

abstract background: in vivo measurements of applied dose during radiotherapy treatment, is important to ensure accurate dose delivery to patients. uncertainty in dose delivery should fall within ±5% of the prescribed dose as recommended by icru. assessment of dose for radiotherapy applications performed with various types of detectors. in this study, semiconductor diodes were used which have s...

 Background: Although some patients can tolerate colonoscopy procedure using fentanyl/ midazolam without any sedation and analgesic requirements but some patients may require additional sedation with benzodiazepines. We performed the present study to compare the effect of paracetamol/midazolam with fentanyl/ midazolam. Methods: In a clinical trial, 96 patients aged 18 to 75 years old, ...

The dose-volume histogram (DVH) is a clinically relevant criterion to evaluate the quality of a treatment plan. It is hence desirable to incorporate DVH constraints into treatment plan optimization for intensity modulated radiation therapy. Yet, the direct inclusion of the DVH constraints into a treatment plan optimization model typically leads to great computational difficulties due to the non...

Introduction: Delivering maximum dose to tumor and minimum dose to normal tissues is the most important goal in radiotherapy. According to ICRU, the maximum acceptable uncertainty in the delivered dose compared to the prescribed dose should be lower than 5%, and this is because of the relationship between absorbed dose, tumor control and normal tissue damage. Absorbed dose accuracy is investiga...