Nodes that have a short axis < 10 mm are considered non-pathological and should not be recorded. When a node increases in size so that the short axis is ≥10mm then the criteria for being considered malignant have been met. However, nodes that increase from for example 9mm to 11mm may not represent true disease
Lesions that disappear and reappear do not automatically result in PD unless Other criteria are also met (new lesions, increase in the sum of longest diameters ≥ 20%) OR CR (overall) was definitively (*) assigned at the previous assessment. In this scenario, the reappearance of any malignant lesion results in PD. (*) It is recommended
Progressive Disease (PD) is defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase