How does the Lugano staging system differ from Ann Arbor for lymphomas?

• A. Lugano incorporates PET-CT for response assessment and uses more detailed criteria for nodal and extranodal involvement; built upon Ann Arbor
• B. Lugano uses MRI instead of PET-CT
• C. Lugano ignores nodal involvement
• D. Lugano is identical to Ann Arbor

Answer: (A)

Lugano updates lymphoma evaluation by using PET-CT to assess both stage and treatment response, rather than relying mainly on anatomical size seen on CT alone as in Ann Arbor. This means nodal and extranodal involvement are determined not just by how big a node looks, but by metabolic activity, so small nodes with high FDG uptake can be considered involved. For response assessment, Lugano uses metabolic criteria, typically with the Deauville five-point scale, to distinguish complete metabolic response from residual disease, which can be more accurate than CT-based size changes alone. Because of these changes, the system was developed as an evolution of Ann Arbor, not a repetition of it, making it more precise in modern imaging contexts. The other statements aren’t correct because Lugano does not switch to MRI, does not ignore nodal disease, and is not identical to Ann Arbor.