RECIST 1.0:

• Not specifically defined, but see EORTC – RECIST Questions and Answers (www.EORTC.be/recist/) “Appearance of new lesion as indicator of progression is only relevant for overall response evaluation.”

RECIST 1.1:

• Finding of a new lesion should be unequivocal: i.e. not attributable to differences in scanning technique, change in imaging modality or findings thought to represent something other than tumor. This is particularly important when patient’s baseline lesions show PR or CR
• When in doubt, subsequent timepoint should be evaluated
• Lesion seen in anatomical region which was not imaged at baseline = new lesion