Advanced Physics for Brachytherapy 2018

Translating random uncertainties to EQD2:

absorbed dose (Gy) d abs

+

- D d

d

+ D d

-

d

abs

abs

equieffective dose dose (Gy EQD2) d EQD2

+

d

-

d

EQD2

EQD2

>

EQD2

dose/fx

e.g. n~500 with same prescribed dose and SD 30% / fx: mean of delivered doses

> from 500 patients > prescribed dose in EQD2

d abs ……… prescribed dose (Gy) d EQD2 ……. d abs

converted to (Gy EQD2)

D d ……. … e.g. 30% d abs

(Gy)

d abs -/+ ……. prescribed dose –/+ D d (Gy) = delivered dose in Gy d EQD2 -/+ …… d abs -/+ converted to Gy EQD2

- = d

+ - d

- < d

+ – d

d

- d

d

– d

abs

abs

abs

abs

EQD2

EQD2

EQD2

EQD2