introduction: during radiotherapy, high accuracy in the dose delivery is required because there is a strong  relationship between the absorbed dose, local tumor control and particularly the normal tissue damage. in  many institutions, in vivo dosimetry using diodes is performed to check the actual dose delivered. in general,  the uncertainty in the dose delivered should fall within  ± 5% of the...

PURPOSE To quantify the clinically observed dose enhancement adjacent to cranial titanium fixation plates during post-operative radiotherapy. METHODS Irradiation of a titanium burr hole cover was simulated using Monte Carlo code MCNPX for a 6 MV photon spectrum to investigate backscatter dose enhancement due to increased production of secondary electrons within the titanium plate. The simulat...

background: one of the means of assessing dose to patients from computed tomography (ct) procedure is through the determination of the skin entrance dose (esd) with the appreciation of the concern that ocular exposure effects from ct scan includes possible induction of cancer and cataract. due to the relatively more recent introduction of ct scans, little work has been done in this area in the ...

background: intraoral radiographs are believed to deliver low doses to patients, thus little work has been done in this regards. considering the increment in the number of patients reporting for the examination and the probability of delayed somatic effects for accumulated low doses of x-irradiation, it is expedient to determine the doses to three critical organs eye, thyroid and parotid that a...

The purpose of this project is to investigate the advantages in dose distribution and delivery of proton beams focused by a triplet of quadrupole magnets in the context of potential radiosurgery treatments. Monte Carlo simulations were performed using various configurations of three quadrupole magnets located immediately upstream of a water phantom. Magnet parameters were selected to match what...

The objective of this work was to estimate patient doses (dose-area product, organ dose, effective dose and entrance surface dose) for barium procedures. A total of 175 procedures, in 175 patients, for five different examination categories was analysed. Dose-area product was determined using a transmission ionization chamber. Organ dose and effective dose were assessed using a knowledge of the ...

Evaluation of entrance surface dose and scattered to the pelvis for common radiological examinations in analog digital radiography: A phantom study