Background: Considering that some vital organs exist in the head and neck region, the treatment of tumors in this area is a crucial task. The existence of air cavities, namely sinuses, disrupt the radiotherapy dose distribution. The study aims to analyze the effect of maxillary, frontal, ethmoid and sphenoid sinuses on radiotherapy dose distribution by Monte Carlo method.Materials and Methods: ...

BACKGROUND AND PURPOSE The purpose of this study was to quantify dose distribution errors by comparing actual dose measurements with the calculated values done by the software. To evaluate the outcome of radiation overexposure related to Panama's accident and in response to ensure that the treatment planning systems (T.P.S.) are being operated in accordance with the appropriate quality assuranc...

Distribution, metabolism, and excretion of monochloroacetic acid (MCA) were examined in adult male rats at a subtoxic (10 mg/kg) and a toxic (75 mg/kg) dose. Rats were injected i.v. with [14C]MCA and housed individually. Urine and feces were collected. Animals were euthanized at different time intervals after dosing and tissues procured. Radioactivity in aliquots showed very rapid distribution ...

background: monte carlo and experimental relative dose determination in a water phantom, due to a high dose rate (hdr) 192ir source is presented for real energy spectrum and monochromatic at 356 kev. materials and methods: the dose distribution has been calculated around the 192ir located in the center of 30 cm ×30 cm ×30 cm water phantom using mcnp4c code by monte carlo method. relative dose v...

background: the dosimetric performance of eclipse 6.5 three dimensional treatment planning system (3dtps) is evaluated by comparing the calculated and measured dose in two dimensions following the guide lines of american association for physicists in medicine task group 53. materials and methods: the calculations were performed by the 3dtps for symmetric as well as asymmetric fields for standar...

The growing use of cone-beam computed tomography (CBCT) for IGRT has increased concerns over the additional radiation dose to patients. The in-field dose of IGRT and the peripheral dose (PD) from kilovoltage CBCT (KV-CBCT) imaging have been well quantified. The purpose of this work is to evaluate the peripheral dose from megavoltage CBCT (MV-CBCT) imaging for nasopharyngeal carcinoma IGRT, to d...