Introduction Polymer gel dosimeters offer a practical solution to 3D dose verification for conventional radiotherapy as well as intensity-modulated and stereotactic radiotherapy. In this study, EGSnrc calculated and PAGAT polymer gel dosimeter measured dose profiles from single shot irradiation with 18 mm collimator of Gamma Knife in homogeneous and inhomogeneous phantoms were compared with eac...

Background: In Radiation Therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or Cerrobend blocks. The current work focuses on the physical characteristics of Cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. Materials and Methods: All measurements were performed using ...

I T HAS been recognized that intracavi-tary irradiation is essential in the treatment of carcinoma of the uterine cervix. Since the beginning of the present century3 many applicators have been used to irradiate the uterus and vagina and later several afterloading techniques have been de-scnibed. " 4 Some of the techniques involve the use of remote control5 " and linear distribution of the sourc...

BACKGROUND This work explores how the choice of prescription isodose line (IDL) affects the dose gradient, target coverage, and treatment time for Gamma Knife radiosurgery when a smaller shot is encompassed within a larger shot at the same stereotactic coordinates (shot within shot technique). METHODS Beam profiles for the 4, 8, and 16 mm collimator settings were extracted from the treatment ...

Blanchflower and Oswald (1994) have argued that, in regional data, the level of unemployment is related to the fevel of wages. This result is at variance with an application of the original Phillips curve to regional data, which would predict that the change in wages ought to be related to the unemployment rate. On the other hand, there is considerable empirical support for the expectations-aug...