Advanced Physics for Brachytherapy 2018

Brachytherapy Source Strength

Only the reference air kerma rate (RAKR) K R to a standards laboratory (i.e., NMI or PSDL)

is a quantity that is traceable

RAKR defined as kerma rate to air @ 1 meter in vacuo , corrected for attenuation/scatter

RAKR defined on the source transverse-plane for photons with E > δ δ threshold is dependent on source calibration protocol

RAKR has units Gy/s, also Gy/h or μGy/s (unit conversion - convenience)

mg Ra, mgRaEq, mCi (apparent activity), Bq are not traceable quantities

Obsolete units: mg Ra, mgRaEq, mCi (apparent activity), Bq