Fig. 4From: Development of a PMMA phantom as a practical alternative for quality control of gamma knife® dosimetryOne-dimensional dose distributions using the 16-mm collimator of a Gamma Knife Perfexion. The solid lines indicate measured distributions in the PMMA phantom, and the solid circles indicate results calculated by the GK treatment planning program at the center of a sphere with an 8.0-cm radius. The measured data are expressed a band and its half width is one standard deviation of each pointBack to article page