Up to six (6) nodes should be selected and followed as measurable sites (Target Nodes).
- Target nodes should be categorized into Large Nodes and Small Nodes.
- Large Nodes are those nodes and nodal masses >1.5 cm in longest diameter at baseline regardless of short diameter
- Small Nodes are those nodes and nodal masses >1.0 - ≤1.5 cm in longest diameter and >1.0 cm in short diameter at baseline.
Measurable (Target) extranodal lesions should also be followed and are grouped into one size category.
- Target extranodal lesions must measure >1.0 x 1.0 cm.
- Target extranodal lesions include splenic and hepatic nodules as well as any nodules outside of the spleen and liver which are considered manifestations of disease.
- Although the 2007 IWG-NHL publication does not make a specific recommendation on the number of measurable extranodal sites to be followed, in concordance with the guidance for nodal disease, Perceptive Informatics recommends that (until further scientific validation suggests otherwise), six (6) extranodal lesions should also be followed.