The overall penumbra is usually defined as the distance, p20–80, separating the 20% and 80% of the dose on the beam axis at the depth of interest. This overall penumbra accounts also for the fact that some photons emitted by the distal parts of the source are only partially attenuated by the collimator. Medulloblastoma is the most common type of childhood brain tumor and often spreads to the sp...

The aim of this study was to determine the shuttle dose for all collimator helmets (4, 8, 14 and 18 mm) of the Gamma Knife, model B, in Vienna, Austria. The additional dose accumulated during the transport of the patient in and out of the treatment position should be considered in the dose planning procedure of multicentre treatment regimens and in fractionated stereotactic Gamma Knife radiothe...

OBJECTIVE The purpose of this study was to evaluate a novel disposable lead-free radiation protection drape for decreasing radiation scatter during electrophysiology procedures. BACKGROUND In recent years, there has been an exponential increase in the number of electrophysiology (EP) procedures exposing patients, operators and laboratory staff to higher radiation doses. METHODS The RADPAD w...

Epoxy resins find widespread use as adhesives and coatings in the construction and food industries. The majority of the products are based on resins that use bisphenol A diglycidyl ether (BADGE) as a precursor. This raises the question if BADGE could be a potential source of bisphenol A (BPA). The recent paper by Perez et al. (1) on the estrogenicity of BPA and some of its analogs and derivativ...

introduction: gafchromic ebt films are one of the self-developing and modern films commercially available for dosimetric verification of treatment planning systems (tpss). their high spatial resolution, low energy dependence and near-tissue equivalence make them suitable for verification of dose distributions in radiation therapy. this study was designed to evaluate the dosimetric parameters of...

introduction: ionizing radiations are the hazardous agents in the workplace and all forms of ionizing radiation produce some type of injuries. awareness of application of protection guidelines and knowledge of the principles of radiation protection can play an important role in health of employees. survey of radiation employee’s levels of awareness and practical behavior is essential and should...

PURPOSE To assess the possibility of using a public calibration function for radiochromic film dosimetry in dose QA of highly conformal treatment plans. METHODS EBT3 film calibration strips (3.5 × 20 cm2 from lots A101212 and A011713) were exposed on a Varian Trilogy at a facility to a 10 × 10 cm2 open field at doses of 80, 160, 320 cGy using 6MV photons. Together with a strip of unexposed fi...

PURPOSE Radiochromic film provides dose measurement at high spatial resolution, but often is not preferred for routine evaluation of patient-specific intensity modulated radiation therapy (IMRT) plans owing to ease-of-use factors. The authors have established an efficient protocol that combines calibration and measurement in a single scan and enables measurement results to be obtained in less t...

the cancer of oral cavity is related to lesions of mucous membrane of tongue and gum that can be treated with radiation therapy. a lateral photon field can be used to treat this kind of tumor, which has a side‑effect on normal tissue in the opposite side of the oral cavity. in this study the dosimetric effect of the various shields in oral cavity is evaluated. in this study, a special phantom s...