If an abnormal lymph node (recorded as Target or Non Target) ‘disappears’ (i.e cannot be seen for Non Target nodes or is < 10 mm) but then ‘reappears’ (i.e. visible for Non Target nodes or ≥ 10mm for nodes considered Target lesions at baseline) is this considered to be continued CR or PD?
Nodes require special consideration as nodes <10 mm are considered benign. Thus, a node is only considered to have ‘reappeared’ if it is ≥ 10 mm (Target lesion) or has unequivocally progressed (Non Target lesion).
As always, the overall context must be considered. Patients with bulky non nodal disease in CR (*), in whom a single node becomes visible on a CT scan, with no evidence of recurrence elsewhere, should ideally be reimaged prior to a decision regarding recurrence being made.
(*) It is recommended that CR in previous cycle is confirmed – lesions may have in fact always been present but have been indistinct. In such cases, PR may be appropriate for both assessments