Advanced Physics for Brachytherapy 2018

Methodology for Uncertainty Estimation

Guide to Expression of Uncertainty in Measurement ISO GUM (2010) precision ≠ accuracy Type A (statistical: standard deviation of results) Type B (non-Type A uncertainties) Law of Propagation of Uncertainty (no covariations) TG-138 applies principles for expressing brachytherapy dosimetric uncertainties

expanded uncertainty, k = 2 (95.45% confidence, 21/22) special case for large # DOF k = t-factor otherwise with covariations

DeWerd, et al, Med. Phys. 38, 782-801 (2011)