CPB Ljubljana 2018 course book

VOLUMETRIC HOMOGENEITY PARAMETERS

UNIFORMITY INDEX (UI) The narrower the peak, the more uniform the dose distribution is. The UI depends on the prescribed dose and high dose HD It expresses the amount of the treatment volume which is concentrated between the prescription dose, PD, and the high dose side of the peak, HD. QUALITY INDEX (QI) QI is similar to UI, but uses the low dose (LD)

Natural Dose Volume Histogram

It is independent on the prescribed dose

The arrows shows the low dose LD and high dose HD The LD and HD is used to define the QI and UI, respectively

Major T, Fröhlich G, Polgar C. Assessment of dose homogeneity in conformal interstitial breast brachytherapy with special respect to ICRU recommendations. J Contemp Brachytherapy. 2011; 3(3):150–5.