This invention relates to a method of assessing the change in size of cancerous lesions in humans utilizing CT scans through the application of a boundary detection algorithm capable of detecting subtle changes in CT images. The change assessment method may include the steps for defining boundary regions on a CT scan image, analyzing said boundaries utilizing a computational program containing statistical analysis techniques, and producing a medically useful output showing any change in lesion size. The change assessment method may also be interfaced with other medical diagnostic techniques or devices that are known in the art.