Table 3.

Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST)

Response category	Criteria
Complete metabolic response	Normalization of all lesions (target and nontarget) to SUL less than mean liver SUL and equal to normal surrounding tissue SUL
	Verification with follow-up study in 1 month if anatomic criteria indicate disease progression
Partial metabolic response	> 30% decrease in SUL peak; minimum 0.8 unit decrease*
	Verification with follow-up study if anatomic criteria indicate disease progression
Progressive metabolic disease	> 30% increase in SUL peak; minimum 0.8 unit increase in SUL peak*
	> 75% increase in TLG of the 5 most active lesions
	Visible increase in extent of FDG uptake
	New lesions
	Verification with follow-up study if anatomic criteria indicate complete or partial response
Stable metabolic disease	Does not meet other criteria

^*Primary outcome determination is measured on the single most active lesion on each scan (not necessarily the same lesion). Secondary outcome determination is the summed activity of up to 5 most intense lesions (no more than 2 lesions per organ).

Abbreviations: SUL, standardized uptake value using lean body mass; TLG, total lesion glycolysis.

Table modified from Wahl et al. ²⁷.