It is pointed out that genotype-based approaches are unlikely to be effective at dose individualization. Delivered dose, which refers to the amount of drug delivered to the point of action to be measured by quantitative imaging techniques, is a drug-centric phenotype that separates pharmacokinetic effects from pharmacodynamic effects. Delivered dose serves as a midway measurable numeric parameter between drug administration and therapy outcome. One potential way to reduce chemotherapy outcome variation is to individualize prescribed drug so that uniform delivered dose is achieved across the patient population.