Accurate relative stopping power prediction from dual energy CT for proton therapy: Methodology and experimental validation

University of Groningen

Accurate relative stopping power prediction from dual energy CT for proton therapy

van Abbema, Joanne Klazien

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Publication date: 2017

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van Abbema, J. K. (2017). Accurate relative stopping power prediction from dual energy CT for proton therapy: Methodology and experimental validation. Rijksuniversiteit Groningen.

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Stellingen

Accurate relative stopping power prediction from

dual energy CT for proton therapy

Methodology and experimental validation

1. The clinically applied single energy CT method based on tabulated average tissue compositions and densities or tissue substitutes can inherently not accurately predict relative proton stopping powers for the variety of tissues present in individual patients.

2. Dual energy CT outperforms single energy CT for relative proton stopping power prediction. (Chapter 5)

3. Predictions based on experimentally validated physics models are in general to be preferred over those based on phenomenology. 4. Spectral CT in the clinical photon energy domain will not lead to a

significant improvement of tissue characterization in terms of detailed material composition information with respect to dual energy CT. (Chapter 6.5)

5. Monte Carlo based treatment planning is a must for proton therapy. 6. A proton therapy institute should implement the most accurate method

for dose calculation, not just the method provided by the contracted company for treatment planning software.

7. In the estimation of proton stopping powers the applied correction terms in the Bethe-Bloch equation should correspond to the correction terms used for experimental determination of mean excitation energies. 8. The use of a 78 eV mean excitation energy for water in practice is

inconsistent with the use of Bragg’s additivity rule for compounds and leads to inconsistencies in relative stopping powers. (Chapter 3.5, 5.3) 9. The peer review process sometimes frustrates advances in science by

not publishing results that fall outside the governing consensus. 10. Fusion of organizations is subject to disintegration unless sufficient