Dr. Levine is recognized for assembling a rigorous and compelling technical foundation to supplant the current method of measuring tumor size—a key to objectively assessing the response of a patient to radiation or chemotherapy treatment with a vastly improved and more accurate approach. Standard practice is to estimate tumor size by measuring the maximum tumor length in a selected 2-D image captured by a 3-D imaging technology, such as CT or MRI. Levine methodically showed that direct measurement of a tumor's three-dimensional volume provides a superior measure of tumor response to therapy. He developed both the theoretical tools and reference artifacts needed to implement accurate tumor volume measurements in medical imaging.