Introduction: Monte Carlo method is often applied in radiation therapy as utilized in all the branches of science. An important requirement for successful radiotherapy is carefully examine the dose distribution specifications and decrease the difference between these features with experience to an acceptable level. In this study, the characteristics of 6, 15 and 20 MeV incident x-rays are prov...

background: monte carlo (mc) modeling of a linear accelerator is a prerequisite for monte carlo dose calculations in external beam radiotherapy. in this study, a simple and efficient model was developed for elekta sl-25 linear accelerator using mcnp4c monte carlo code materials and methods: the head of elekta sl-25 linac was simulated for 6 and 18 mv photon beams using mcnp4c mc code. energy sp...

background: it was intended to investigate the effect of physical wedge (pw) and enhanced dynamic wedges (edw) on contralateral breast dose during primary breast irradiation in radiotherapy treatment, using high energy photon beams. materials and methods: the varian’s clinac dual mode linear accelerator model 2100 c/d and siemen’s primus accelerators were used for radiation doses with 6 mv and ...

the aim of radiation therapy treatment planning is to achieve an optimal balance between delivering a high dose to target volume and a low dose to healthy tissues. in order to refrain any complications resulting from the dose to the surrounding normal organs, the role of treatment plan has been critically evaluated in term of how large the volume or mass of normal tissues exposed in the radiati...

background: palliative whole brain radiotherapy (wbrt) has been the standard treatment for brain metastases. ionizing radiation is known to be one of the most potent cataractogenic agents. we aimed to evaluate two different radiotherapy techniques with respect to the doses received by the organs at risk (oar) in patients with brain metastasis who undergone wbrt. materials and methods: ten conse...

background: radiotherapy plays an important role in the management of most malignant and many benign primary central nervous system (cns) tumors. radiotherapy affects both tumor cells and uninvolved normal cells; so, it is important to estimate absorbed dose to organs at risk in this kind of treatment. the aim of this study was to determine the absorbed dose to chiasma, lens, optic nerve, retin...

Background: Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery.Objective: In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy plannin...

In radiotherapy for head and neck cancer, the radiation dose delivered to the pharyngeal mucosa (mucosal lining of the throat) is thought to be a major contributing factor to dysphagia (swallowing dysfunction), the most commonly reported severe toxicity. There is a variation in the severity of dysphagia experienced by patients. Understanding the role of the dose distribution in dysphagia would ...