Comparison of RECIST, iRECIST, and PERCIST for the Evaluation of Response to PD-1/PD-L1 Blockade Therapy in Patients With Non–Small Cell Lung Cancer

Abstract

Purpose The aim of this study was to compare the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, the immune RECIST (iRECIST) criteria, and the Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) 1.0 in patients with advanced non–small cell lung cancer treated with programmed cell death protein 1 (PD-1)/programmed cell death protein 1 ligand (PD-L1) inhibitors. Methods This prospective study of 42 patients treated with a PD-1/PD-L1 inhibitor was approved by our institutional review board, and all patients gave written, informed consent. Tumor burden dynamics were assessed on 18F-FDG PET/CT before and after treatment initiation. Immunotherapeutic responses were evaluated according to RECIST 1.1, iRECIST, and PERCIST 1.0 for the dichotomous groups, responders versus nonresponders. Cohen κ and Wilcoxon signed rank tests were used to evaluate concordance among these criteria. We assessed progression-free survival and overall survival using the Kaplan-Meier estimator. Results The RECIST 1.1 and PERCIST 1.0 response classifications were discordant in 6 patients (14.2%; κ = 0.581). RECIST 1.1 and iRECIST were discordant in 2 patients, who evidenced pseudoprogression after treatment initiation. Median progression-free survival, as well as overall survival, was significantly longer for responders compared with nonresponders for all criteria (P < 0.001), with no significant difference between the 3 criteria (P > 0.05). Conclusions RECIST 1.1 and PERCIST 1.0 show only moderate agreement, but both can predict treatment response to PD-1/PD-L1 inhibitor therapy. In case of pseudoprogression, metabolic tumor activity may help to correctly classify treatment response.

Defining tumor resistance to PD-1 pathway blockade: recommendations from the first meeting of the SITC Immunotherapy Resistance Taskforce

“…The general consensus of the taskforce was that iRECIST was not yet standard and required additional validation. Efforts are ongoing to develop response criteria using positron emission Open access tomography (PET) scans to measure changes in flurodeoxyglucose (FDG) uptake, 21 yet the taskforce consensus was that this modality has not yet been sufficiently developed or validated. All three working groups agreed that FDG/PET may be an indicator of response to PD-(L)1 inhibitors and that interpretation may be confounded by metabolically active immune infiltrates that can accompany regressing tumor lesions.…”

Princípios básicos e aplicações oncológicas da PET-CT/18F-FDG

“…Em uma comparação entre estes dois critérios, Sager et al 35 mostraram que os achados metabólicos da PET-CT foram menos eficientes que os resultados morfológicos da CT e RMN em pacientes com carcinoma hepatocelular tratados com microesferas marcadas com Ítrio-90, porém, foram mais significativos para o tratamento de metástases de câncer colorretal. De forma semelhante, outros estudos mostram que, apesar de serem divergentes em alguns casos, o RECIST e PERCIST são importantes critérios para predizer a resposta do câncer a tratamentos imunoterápicos 36 .…”

Particular findings on lung CT in patients undergoing immunotherapy for bronchogenic carcinoma

“…All patients gave written, informed consent prior to 2-[ 18 F]fluoro-2-deoxy-D-glucose ([ 18 F]FDG) PET/CT examinations. Of the five patients reported in this manuscript three were also included in a previous manuscript [15]. Patients with an atypical response pattern or radiologically detectable immune-mediated adverse events were retrospectively identified based on a prospectively collected group of 70 NSCLC patients under PD1 or PD-1L therapy between 2016 and 2019.…”