Simple and Versatile Pharmacokinetic Model for Radioligand Therapy

In recent years radioligand therapy has emerged as an effective treatment modality for various solid malignancies, with pharmacokinetic modeling being routinely used for absorbed dose calculation and patient-specific therapy planning. Exemplary time-activity curves of FAP-targeted radioligands in a mouse model are accurately fitted by a sum of right skew biexponential distributions with four adjustable parameters in total. This type of modeling function is versatile and also suitable for conventional drugs. For further insight, an auxiliary equation is derived that relates tumor clearance to FAP expression and the radioligand dissociation constant.