Particle Therapy 2017

Relative Uncertainty in the SOBP:

Variation of the RBE as a function of various parameters

(depth, dose, beam energy, fractionation, tumor type, etc.)

Precision

probably around 10%

Absolute uncertainty:

Absolute value of the RBE, which determines the applied

biological effective dose

Accuracy

of RBE(C12) probably around 20% - 30%

Comparison:

Clinical Proton-RBE: ~10-20%

RBE for Brachytherapy (

125

I and

103

Pd): ~1.5 (+-20%)

Changes of fractionation schemes (using



): ~15%

The Uncertainty of RBE (personal view)

“Correct doses” have to be evaluated in clinical studies