Table 2.

Overview metabolic and combined response evaluation to immunotherapy

Criteria (year) [reference]	Modality	Categories
		Complete response	Partial response	Stable disease	Progressive disease
EORTC (1999) [31]	PET	• Reduction of 18F-FDG uptake to background levels	• ≥ 15% reduction of 18F-FDG uptake	• Neither CR, PR, nor PD	• ≥ 25% increase in 18F-FDG uptake
PERCIST (2009) [33]	PET	• Reduction of 18F-FDG uptake to the level of background blood pool	• ≥ 30% reduction in SUL peak • Minimum of 0.8 SUL units of measurable lesions	• Neither CR, PR, nor PD	• > 30% increase in SUL peak • Minimum of 0.8 SUL units of measurable lesions
PECRIT (2017) [34]	PET/CT	• Disappearance of all metabolically active tumours and TL • SAD reduction target lymph nodes < 10 mm • No new lesions	• ≥ 30% reduction in SUL peak • ≥ 30% decrease in TL diameter sum	• Neither CR, PR, nor PD	• > 30% increase in SUL peak • Or new metabolically active lesion • ≥ 20% increase in target lesion diameter (minimum 5 mm) • Or new lesions
PERCIMT (2018) [35]	PET/CT	• Complete resolution of all 18F-FDG-avid lesions • No new FDG avid lesions	• Complete resolution of some 18F-FDG-avid lesions • No new 18F-FDG-avid lesions	• Neither CR, PR, nor PD	• ≥ 4 new lesions with ≤ 10 mm functional diameter • Or three or more new lesions with > 10 mm functional diameter • Or two or more new lesions with > 15 mm functional diameter

CR Complete response, CT Computed tomography, FDG Fluorodeoxyglucose, PD Progressive disease, PET Positron emission tomography, PR Partial response, SAD Short-axis diameter, SUL SUV corrected for lean body mass, TL Target lesions