=====Macdonald criteria=====
The Macdonald criteria,
((Macdonald DR, Cascino TL, Schold SC, Cairncross G. Response criteria for phase II studies of malignant glioma. J Clin Oncol. 1990;8:1277-1280))
used 2-dimensional set of measurements for assessing tumor response, measure maximal enhancing tumor diameter on a single axial contrast-enhanced T1-weighted image and the largest perpendicular diameter on the same image 

{{http://img.medscape.com/article/776/272/776272-fig14.jpg}}

http://img.medscape.com/article/776/272/776272-fig14.jpg


The product of these measurements is calculated, and the measurements are repeated with each scan. 

RECIST
((Therasse P, Arbuck SG, Eisenhauer EA, et al. New guidelines to evaluate the response to treatment in solid tumors. J Natl Cancer Inst. 2000;92:205-216.))
, which has become the standard set of criteria for assessing response in systemic cancers, measures the longest single linear enhancing diameter across a lesion in the axial plane and repeats this on follow-up studies, regardless of changes in the original orientation or section