Multi-institutional retrospective analysis of the inhomogeneity correction for radiation therapy of lung cancer.

The purpose of this work is to retrospectively analyze the effect of the inhomogeneity correction using clinically treated plan of stage III non-small-cell lung cancer within multiple institutions in Japan. Twenty-five patients among five facilities of radiation therapy were registered for this study. The isocenter dose or D(95) of PTV or other important values were compared with and without an inhomogeneity correction using model-based algorithm.

Monte Carlo calculations of correction factors for plastic phantoms in clinical photon and electron beam dosimetry.

The purpose of this study is to calculate correction factors for plastic water (PW) and plastic water diagnostic-therapy (PWDT) phantoms in clinical photon and electron beam dosimetry using the EGSnrc Monte Carlo code system. A water-to-plastic ionization conversion factor k(pl) for PW and PWDT was computed for several commonly used Farmer-type ionization chambers with different wall materials in the range of 4-18 MV photon beams. For electron beams, a depth-scaling factor c(pl) and a chamber-dependent fluence correction factor h(pl) for both phantoms were also calculated in combination with NACP-02 and Roos plane-parallel ionization chambers in the range of 4-18 MeV.