TABLE 3.
18F-FDG PET/CT assessing criteria for immunotherapy.
| Criteria | CR/CMR | pR/PMR | SD/SMD | pD/PMD | Notes |
|---|---|---|---|---|---|
| PECRITCho et al., 2017 (Cho et al., 2017) | Disappearance of all target and non-target lesions without any new lesions. Any pathological lymph nodes must have a reduction in short axis to <10 mm. Determined by two observations not less than 4 weeks apart | At least a 30% decrease in the sum of maximum diameters of target lesions; no new lesions; no progression of disease | 1. Does not meet the criteria for CR, PR, or PD, taking the smallest sum of the maximum diameters of target lesions as referencesAnd | 1. Sum of the maximum diameter of lesions increased by >20% over the smallest achieved sum of maximum diameter. The appearance of one or more new lesions is always considered progressionOr | |
| 2. Then, 18F-FDG PET (SCAN 2) assessment is required after 3-4 weeks: i) when percent change in SULpeak per PERCIST criteria is more than 15.5%, the SMD will be confirmed | 2. SD/SMD; then, 18F-FDG PET (SCAN 2) assessment is required after 3-4 weeks: ii) when the percent change in SULpeak is less than or equal to 15.5%, this pattern will be confirmed as PMD. | ||||
| ≥4 months of clinical benefit | ≥6 months of clinical benefit | ≥6 months of clinical benefit | No clinical benefit | ||
| PERCIMT Anwar et al., 2018 (Anwar et al., 2018) | Disappearance of metabolically active lesions | Disappearance of some metabolically active lesions | Neither CR/CMR, pR/PMR, nor pD/PMD | 1.4 new lesions with functional size <1.0 cm | |
| 2.3 new lesions with functional size >1.0 cm | |||||
| 3.2 new lesions with functional size >1.5 cm | |||||
| iPERCIST Goldfarb et al., 2019 (Goldfarb et al., 2019) | Complete resolution of FDG uptake within the target lesion | 1. ≥30% decrease in the target tumor FDG SULpeakor | Neither CR/CMR, pR/PMR, nor pD/PMD | 1. ≥ 30% increase in FDG SULpeak or advent of new FDG-avid lesions (UPMD) | |
| 2. confirmed as PMR by SCAN-3 from UPMD at SCAN-2 | 2. Need to be confirmed by a third PET (second posttreatment scan) at 4–8 weeks later (CPMD); if progression is followed by PMR or SMD, the bar is reset | ||||
| (Clinical stability is considered when deciding whether treatment is continued after UPMD) | |||||
| Responders | Responders | Responders | Non-responders | ||
| imPERCIST5 Ito K et al., 2019 (Ito et al., 2019) | Complete resolution of FDG uptake within all lesions to a level of less than or equal to that of the mean liver activity and that is indistinguishable from the background (blood-pool uptake) | Reduction of at least 30% in the sum of SULpeak of all target lesions detected at baseline and an absolute drop of 0.8 SULpeak units | Neither CMR, PMR, nor PMD. | 1. Increase in at least 30% in the sum of SULpeak of all target lesions detected at baseline, and an absolute increase in 0.8 SULpeak units with exclusion of infection/treatment effect | Target lesion: up to five measurable target lesions, typically the five hottest lesions among all lesions, including new lesions, and no more than two per organ |
| Patients with appearance of new FDG-avid lesions must be confirmed 4–8 weeks later | |||||
| PMR or SMD with appearance of new FDG-avid lesions at 4–8 weeks must be reevaluated | PMR or SMD with appearance of new FDG-avid lesions at 4–8 weeks must be reevaluated |
18F-FDG: 2-deoxy-2-[18F]-fluoro-D-glucose; PET/CT: positron emission tomography/computed tomography; CR: complete response; CMR: complete metabolic response; PR: partial response; PMR: partial metabolic response; SD: stable disease; SMD: stable metabolic disease; PD: progressive disease; PMD: progressive metabolic disease; SULpeak: peak standardized uptake values normalized by lean body mass; FDG: fluorodeoxyglucose; UPMD: unconfirmed progressive metabolic disease; CPMD: confirmed progressive metabolic disease; HPD: hyper-progression.