Table 1.

Overview CT-based criteria for response assessment

	RECIST 1.1 (2009)	irRC (2009)	irRECIST (2013)	iRECIST (2017)	imRECIST (2018)
Complete response	• Disappearance of all TL/NTL • Nodal SAD < 1.0 cm • No new lesion	• Disappearance of all lesions (measurable or not) • No new lesions • Confirmation by consecutive CSI control in ≥ 4 weeks	• Disappearance of all TL/NTL • Nodal SAD < 1.0 cm • No new lesion	• Disappearance of all TL/NTL • Nodal SAD < 1.0 cm • No new lesion	• Disappearance of all TL/NTL • Nodal SAD < 1.0 cm • No new lesion
Partial response	• ≥ 30% decrease relative to baseline • No new lesion	• ≥ 50% relative to baseline • Confirmation by consecutive CSI control in ≥ 4 weeks	• ≥ 30% decrease relative to baseline • No new lesion	• > 30% decrease relative to baseline • No new lesion	• ≥ 30% decrease relative to baseline • No new lesion
Stable Disease	• Neither CR, PR nor PD	• Neither CR, PR nor PD	• Neither CR, PR nor PD	• Neither CR, PR nor PD	• Neither CR, PR nor PD
Progressive Disease	• ≥ 20% increase relative to baseline • Or progression of NTL • Or new lesion	• ≥ 25% increase relative to nadir • New lesions added to tumor burden • Confirmation by consecutive CSI control in ≥4 weeks	• ≥ 20% increase • And ≥ 5 mm absolute increase in total measured tumor burden relative to nadir(i. E. minimum recorded tumor burden). • Confirmation of progression in ≥4 weeks after suspected PD	iUPD: PD RECIST 1.1 iCPD: • Confirmation 4–8 weeks later • Any further size increase in TL sum >5 mm • Any progression of NTL • Any further size increase of the sum of new TL > 5 mm • Appearance of another new lesion	• ≥ 20% increase of summed tumor burden of TL including new lesions compared to nadir • New lesions/NTL progression do not necessarily define PD • Negated in a subsequent follow-up ≥ 4 weeks with non-PD
Reference	[21]	[22]	[23, 24]	[25]	[26]

Abbreviations: TL target lesion; NTL non-target lesion; SAD short-axis-diameter, CSI cross sectional imaging; PD progressive disease; iUPD unconfirmed PD; iCPD confirmed PD