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...

Philips DigitalDiagnost, a digital radiographic system mounting flat panel detector (FPD), can display dose area data (DiDi dose) calculated by examination parameters. We evaluated its fundamental characteristics and compared the values of DiDi dose andactual measured data obtained by the area dose product meter (PD-4100L). Tendency of varied values of mAs, X-ray tube values and exposure area f...

The current study aimed to: a) utilize Monte Carlo simulation methods for the assessment of radiation doses imparted to all organs at risk to develop secondary radiation induced cancer, for patients undergoing radiotherapy for breast cancer; and b) evaluate the effect of breast size on dose to organs outside the irradiation field. A simulated linear accelerator model was generated. The in-field...

PURPOSE To study the effect of different filters on the dose response curves of the Gafchromic XRQA2 film. To measure the kV XVI cone-beam CT (CBCT) surface dose received during 3D and 4D imaging protocols in three body regions (head and neck, chest and pelvis). METHODS GafChromic XR- QA2 film (International Specialty Products, Wayne, NJ) dose response curves were generated for three irradiat...

Conformal Radiation Therapy (3DCRT) and Intensity Modulated Radiotherapy (IMRT) improve the relationship between tumor control and complications in normal tissue. However, these techniques may cause an increase of the normal tissue volume irradiated with low doses or an increase of the doses outside the beam. The aim of this work was to measure and compare the scatter dose to the contralateral ...

Sites and mechanisms of the antagonistic action of TA-0910, a new thyrotropin-releasing hormone (TRH) analog, on pentobarbital anesthesia were studied in rats. Intravenous administration of TA-0910 dose-dependently shortened the duration of pentobarbital anesthesia at 30 micrograms/kg or more. The anti-anesthetic action of TA-0910 after intracerebral injection was in the following order of effe...

PURPOSE To quantify daily variations in the anatomy of patients undergoing radiation therapy for prostate carcinoma, to estimate their effect on dose distribution, and to evaluate the effectiveness of current standard planning and setup approaches employed in proton therapy. METHODS We used series of computed tomography data, which included the pretreatment scan, and between 21 and 43 in-room...

The purpose of this study was to develop a simplified methodology that will produce Monte Carlo (MC) dose distribution for proton therapy which can be used as a clinical aid in determining the adequacy of proton plans produced from the treatment planning system (TPS). The Geant4 Monte Carlo toolkit was used for all simulations. The geometry of the double scatter nozzle in the simulation was a s...

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...

OBJECTIVE Amyotrophic lateral sclerosis is a progressive degenerative disease, which typically leads to death in 3 to 5 years. Neuronal cell death offers a potential target for therapeutic intervention. Ursodeoxycholic acid is a cytoprotective, endogenous bile acid that has been shown to be neuroprotective in experimental Huntington and Alzheimer diseases, retinal degeneration, and ischemic and...