Fig. 1.
RPIArc/RPIIMRT ratio calculated for each patient and for the three groups of weight factors. Red line represents the RPIArc/RPIIMRT ratio equal to 1, when no difference between the plans is observed. IMRT provides better dose distribution than RapidArc in respect to RPI value for points located below the red line (RPIArc/RPIIMRT < 1). Points located above the red line represent values of the RPIArc/RPIIMRT ratio which are higher than 1. For these points RapidArc provides better dose distribution in respect to the RPI index.