Dose volume histogram of a patient with prostate cancer. Dose volume histogram (relation of relative volume to delivered relative dose) from one patient for PTV (red), rectum (blue) and bladder (yellow) for different dose rates (DR) and leaf velocities (LV): circle – DR 100 MU/min and LV 1.0 cm/sec. triangle – DR 100 MU/min and LV 10.0 cm/sec. sun – DR 600 MU/min and LV 1.0 cm/sec. square – DR 600 MU/min and LV 10.0 cm/sec.