Figures & data
Figure 1. 2D-maps of the population-based margins, showing both the margins for all nine patients (upper) and the margins when the one female patient was excluded due to anatomically unexpected motion (lower). Superior direction is found at θ = 90˚ and inferior at θ = –90˚. Anterior, posterior as well as left and right directions are seen for θ = 0˚, with posterior at φ = 90˚, anterior at φ = 270˚, left at φ = 0˚/360˚, and right at φ = 180˚. The top and the bottom line of all the 2D-images describe the same point. The colour difference describes the intra-fractional changes in mm.
Table I. The result of a linear regression model for patient-specific margins. Margin is determined as the upper 95% CI times 10 min, since margin should account for a 10 min interval. The bottom table shows the average bladder volume covered by PTV for each patient. The bladders are almost completely covered, with an average of over 99%.
Figure 2. The volume overlap between bowel-cavity and PTV using the margin for patient-specific and population-based intra-fractional motion as well as the PTVs used clinically in the plan-selection strategy.
