ABSTRACT
In this chapter, we take adaptation to include both changes in treatment based on customization to an individual’s biology and modi£cations in dose delivery in response to tissue changes, delivery inaccuracies, uncertainties, or outright delivery errors observed during treatment. We discuss the potential e¢ect of dose “cold spots” either inside a target volume or at the target edge, the e¢ect of dose nonuniformity caused by delivery errors, the rationale for boosting tumors, and the rationale for modifying plans for some patients during a course of therapy to reduce the risk of a complication. We also brie²y discuss several
other types of adaptation, including adaptation to observable spatial variations across a tumor, in particular, for positron emission tomography (PET)-F-18-²uorodeoxyglucose (FDG) uptake; adaption to a patient’s inherent radiosensitivity; and adaptation based on treatment response.
