Table 2. Interobserver agreements for interim and end-of-treatment PET/CT with use of rDS, Deauville score and ΔSUVmax.

	Observer 1 vs. 2
	iPET4	PET-eot
Tumour/Liver ratio (rDS)	0.93	0.84
Deauville score	0.85	0.56
ΔSUVmax	1.00	-

Cohen’s kappa coefficient κ interpretation: 0.00–0.20, slight agreement; 0.21–0.41, fair agreement; 0.41–0.60, moderate agreement; 0.61–0.80, substantial agreement; 0.81–1.00, almost perfect agreement. rDS: ratio Deauville Score = Tumour/Liver SUVmax ratio >1.4 as positive for iPET4 and PET-eot; Deauville score: score ≥ 4 as positive for iPET4 and PET-eot; ΔSUVmax: ≤70% as positive for iPET4.