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.
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.
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).
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.
From the *Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna;
†Respiratory Oncology Unit, Otto-Wagner Hospital, Vienna;
‡Center for Biomarker Research in Medicine, CBmed, Graz; and
§Department of Internal Medicine I & CCC, Medical University of Vienna, Vienna, Austria.
Received for publication October 10, 2018; revision accepted March 21, 2019.
Conflicts of interest and sources of fundings: H.P. received speaker honoraria and is an advisory board member of Boehringer Ingelheim, Roche, MSD, BMS, AstraZeneca, and Novartis. This study was supported by funds from the Oesterreichische Nationalbank (Oesterreichische Nationalbank, Anniversary Fund, grant 16886), “Fond für interdisziplinäre Krebsforschung der Stadt Wien,” and the Theodor Koerner Fund. The institution has grants pending with Siemens Healthineers. None declared to all other authors.
Authors' contributions: L.B., C.H., H.P., and M.E.M. designed the study. L.B., B.S., D.K., H.F., M.H., A.F., D.S., A.R.H., and W.W. managed patients examinations and analyzed data. L.B., H.P., and M.E.M. wrote the manuscript.
Correspondence to: Helmut Prosch, MD, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. E-mail: firstname.lastname@example.org.
Online date: April 23, 2019