Analysis set: all patients qualified for HD15 and for the PET question. PET performed and seen by the PET panel (AS2, number of patients = 311). Reason for divergent recommendation/performance:

Negative residues but radiotherapy recommended due to very large initial and residual mediastinal mass.

Negative residues but radiotherapy against recommendation in 4 cases: PET regarded as positive by local physician (n = 2), unknown reason (n = 2).

Positive residues but no radiotherapy recommended in 3 cases: positive residue in the liver (n = 1), panel too late to recommend radiotherapy (n = 2).

In one case, radiotherapy was performed where no radiotherapy was recommended.