Comparing time activity curves using the Akaike information criterion

The comparison of curves is a common task in many fields of science. Simply comparing the sums of squares or R(2) is not sufficient, and frequently used tests have many disadvantages. The basic idea of the presented method is turning the problem of comparing curves into a problem of model selection using the corrected Akaike Information Criterion. Here, this straightforward approach is applied for comparing curves using the example of (111)In- and (90)Y-labelled anti-CD66 antibody serum time activity data. As a result it is shown that for the investigated (111)In- and (90)Y-labelled anti-CD66 antibodies, the biokinetics between dosimetry and therapy are different with respect to the contribution of the second, longer half-life component. We advocate the use of the presented method rather than employing less advanced approaches for curve comparison.