Tumor response evaluation in patients with malignant melanoma undergoing immune checkpoint inhibitor therapy and prognosis prediction using 18F-FDG PET/CT: multicenter study for comparison of EORTC, PERCIST, and imPERCIST.

Abstract

OBJECTIVE:

In malignant melanoma patients treated with immune checkpoint inhibitor (ICI) therapy, three different FDG-PET criteria, European Organization for Research and Treatment of Cancer (EORTC), PET Response Criteria in Solid Tumors (PERCIST), immunotherapy-modified PERCIST (imPERCIST), were compared regarding response evaluation and prognosis prediction using standardized uptake value (SUV) harmonization of results obtained with various PET/CT scanners installed at different centers.

MATERIALS AND METHODS:

Malignant melanoma patients (n = 27) underwent FDG-PET/CT examinations before and again 3 to 9 months after therapy initiation (nivolumab, n = 21; pembrolizumab, n = 6) with different PET scanners at five hospitals. EORTC, PERCIST, and imPERCIST criteria were used to evaluate therapeutic response, then concordance of the results was assessed using Cohen's κ coefficient. Log-rank and Cox methods were employed to determine progression-free (PFS) and overall (OS) survival.

RESULTS:

Complete metabolic response (CMR)/partial metabolic response (PMR)/stable metabolic disease (SMD)/progressive metabolic disease (PMD) with harmonized EORTC, PERCIST, and imPERCIST was seen in 3/5/4/15, 4/5/3/15, and 4/5/5/13 patients, respectively. Nearly perfect concordance between each pair of criteria was noted (κ = 0.939-0.972). Twenty patients showed progression and 14 died from malignant melanoma after a median 19.2 months. Responders (CMR/PMR) showed significantly longer PFS and OS than non-responders (SMD/PMD) (harmonized EORTC: p < 0.0001 and p = 0.011; harmonized PERCIST: p < 0.0001 and p = 0.0012; harmonized imPERCIST: p < 0.0001 and p = 0.0012, respectively).

CONCLUSIONS:

All harmonized FDG-PET criteria (EORTC, PERCIST, imPERCIST) showed accuracy for response evaluation of ICI therapy and prediction of malignant melanoma patient prognosis. Additional studies to determine their value in larger study populations will be necessary.

• Authors: Kazuhiro Kitajima, Tadashi Watabe, Masatoyo Nakajo, Mana Ishibashi, Hiromitsu Daisaki, Fumihiko Soeda, Atsushi Tanemura, Takuro Kanekura, Naoya Yamazaki, Kimiteru Ito
• Journal: Japanese journal of radiology (Jpn J Radiol) Vol. 40 Issue 1 Pg. 75-85 (Jan 2022) ISSN: 1867-108X [Electronic] Japan
• PMID: 34287739 (Publication Type: Journal Article, Multicenter Study)
• Copyright: © 2021. The Author(s).

Chemical References

• Immune Checkpoint Inhibitors
• Fluorodeoxyglucose F18

Topics

• Fluorodeoxyglucose F18
• Humans
• Immune Checkpoint Inhibitors
• Melanoma (diagnostic imaging, drug therapy)
• Positron Emission Tomography Computed Tomography
• Prognosis
• Treatment Outcome