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. Energ...

breast cancer is the most common cancer in women after skin cancer. in iran, the presentation age of this cancer is younger than the global average. there are different therapeutic methods for treatment of breast cancer and the choice of treatment depends on the stage of the disease as well as its type and characteristics. therapeutic methods include surgery, radiotherapy, and systemic therapie...

External Beam Radiotherapy (EBRT) remains the mainstay for radical treatments, in malignancies in head and neck regions. Teletherapy with cobalt-60 isotope machines are still available for cancer management in countries with more population, and their continuation as a basic machine has been recommended [1]. With linear accelerators, the present day radiotherapy for radical treatments in head a...

background: in this study we evaluated the incidence of hypothyroidism in patients who received external beam radiation due to cancer, when radiation portals included thyroid gland. methods: this prospective study was conducted from april 2004 to december 2005 among patients with head and neck or breast malignancies who referred to radiation oncology department of cancer institute, imam khomein...

A challenging case was reported for a patient treated in decubitus position with proton pencil beam scanning. A regular robust plan with the consideration of the uncertainties of translational alignment and range accuracy cannot ensure the target coverage as revealed in two verification computed tomography (CT) scans during the first week of the treatment. The irreproducibility of daily alignme...

In this research, chromatic confocal microscopy with transverse point beam scanning is constructed for three-dimensional surface measurement without longitudinal mechanical translation. In beam scanning chromatic confocal microscopy, the wavelength-to-depth relation and the lateral field of view should be determined considering the beam scanning angle. With the experimental results from a sampl...

Background and Objective: Hypothyroidism is a known consequence of the external beam radiotherapy to the neck encompassing the thyroid gland for over 40 years. The aim of this study was to find out the incidence of hypothyroidism in patients with head and neck cancer treated with radiotherapy, when radia...