Dose-Volume Histogram (DVH) Analysis Tool

Y-Axis:

Cumulative DVH Curves

Structure Statistics

Dose Constraints

Structure	Constraint	Goal	Actual	Status

Dose Statistics

Structure:

Query Type:

Value: %

Understanding Cumulative DVH

Cumulative DVH shows the percentage of volume receiving AT LEAST a given dose.

The curve starts at 100% at dose = 0 (entire structure receives at least 0 Gy)
The curve decreases monotonically as dose increases
For targets: Ideally steep falloff near prescription dose (good coverage)
For OARs: Ideally rapid falloff (most volume receives low dose)

DVH Analysis Metrics

Common DVH Parameters:

D95, D98: Minimum dose received by 95% or 98% of the volume (coverage metric)
D2, D0.03cc: Near-maximum dose (hot spot evaluation)
V20, V5: Volume (%) receiving at least 20 Gy or 5 Gy (low dose spread)
Mean Dose: Average dose to the structure (calculated as integral of DVH)
Conformity Index (CI): Ratio of prescription isodose volume to target volume
Homogeneity Index (HI): (D2 - D98) / D50 (lower is more homogeneous)