Figure 2From: Planning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markersIsocenter placement errors (in cm) relative to DRR on during-treatment EPIs (gray circles; n = 530 fractions), along a): S-I and A-P axes, and b): S-I and L-R axes. Outer box shows PTV margins used in the study; inner ellipse shows 95% confidence intervals for CTV coverage in each direction.Back to article page