A computerized method for determining an objective tumor response to an anti-cancer therapy using one or more cross-sectional images can comprise receiving one or more cross-sectional images that comprise one or more cross-sectional slices of digital medical image data and identifying one or more target lesions within the one or more cross-sectional images. The method can also comprise analyzing at least one of the target lesions with an image-processing module configured to identify a total range of pixel intensities and restrict the total range of pixel intensities to a first restricted range that corresponds to pixel intensities representative of vascularized tumor. Further still, the method can comprise deriving a vascular tumor burden for the at least one of the one or more target lesions and determining the objective tumor response for the at least one of the one or more target lesions based on the vascular tumor burden.