Modern Bt Techniques - Florence 2016

The Natural Dose Volume Histogram (NDVH)

Natural Dose-Volume Histogram

Two-plane breast implant, SSDS optimized

dV/d(u) × 10 6 ( cm 3 .cGy 3/2 )

Ref. Air Kerma = 0.3206 cGy.m 2

u(D) = D –3/2

5.0

Uniformity Index = 2.26 Quality Index = 3.40

4.0

point source

3.0

2.0

1.0

NPD

Dose (cGy)

PD

LD HD

0.0

500

600 700 800

360

380 400

1000

Natural dose-volume histogram of an optimized two-plane breast implant. The prescription dose PD is defined as 90% of the mean dose in the basal dose points, i.e. 90% of the peak dose value. The prescription dose PD coincides with the natural prescription dose NPD which lies at the base of the peak at the Low Dose side.