Biological weighting of the neutron capture mixed field
In plain words
The patient receives a mixture of $\alpha$ particles, lithium nuclei, protons from nitrogen, fast neutrons and $\gamma$ rays, each with a different biological effect. How to add them into one effective dose is disputed.
Precise statement
Construct a model converting the absorbed dose components of a neutron capture field (B-10(n,alpha)Li-7 at about 2.3 MeV total kinetic energy, N-14(n,p) protons at 0.58 MeV, fast-neutron recoil protons and photons) into a photon-isoeffective dose that predicts tumour control and normal-tissue complication, replacing fixed compound and relative biological effectiveness factors. The model must include the boron microdistribution relative to the nucleus and dose-rate effects over treatment times of 30 to 60 min. An answer is a validated weighting scheme with stated uncertainty.
What would settle it
Prospective comparison of predicted and observed responses across patients or animal models with measured boron microdistribution and beam spectra.
Status in the literature
Fixed-factor and photon-isoeffective dose models give different prescriptions for the same treatment and both remain in use.