Experimental validation of <scp>Geant4</scp> nuclear interaction models in dose calculations of therapeutic carbon ion beams

QGSP_INCLXX_HP demonstrated high dosimetric accuracy in the target region of energy-modulated fields. QGSP_BIC_HP and Shielding showed physics model-related inaccuracies in simulated target dose. Additional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:msub><mml:mi>k</mml:mi> <mml:mrow><mml:mi>N</mml:mi> <mml:mo>/</mml:mo> <mml:mi>MU</mml:mi></mml:mrow> </mml:msub> <mml:annotation>$k_{\rm N/MU}$</mml:annotation></mml:semantics> </mml:math> tuning improved their target dose calculation accuracy with a trade-off of reference dose accuracy. The computationally efficient QGSP_INCLXX_HP and QGSP_BIC_HP are viable candidates for dose calculation applications of carbon ion beam therapy, such as in silico PSQA.