Metabolic imaging with FDG-PET and time to progression in patients discontinuing immune-checkpoint inhibition for metastatic melanoma

Cancer Imaging

Eleftheria Chorti¹  Dirk Schadendorf¹  Lisa Zimmer¹  Anne Zaremba¹  Selma Ugurel¹  Elisabeth Livingstone¹  Lale Umutlu²  Viktor Grünwald³  Ken Herrmann⁴  Justin Ferdinandus⁴  Robert Seifert⁴  Wolfgang Peter Fendler⁴  Francesco Barbato⁴ 

[1] Department of Dermatology, University of Duisburg-Essen and German Cancer Consortium (DKTK), University Hospital Essen, Hufelandstr, 55, 45147, Essen, Germany;Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany;Department of Medical Oncology, West German Cancer Center, University Hospital Essen, Essen, Germany;Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen, Hufelandstr, 55, 45147, Essen, Germany;

关键词: Melanoma;    Immunotherapy;    Checkpoint inhibition;    PET;    FDG;    Discontinuation;   

DOI  :  10.1186/s40644-022-00449-3

来源: Springer

【 摘 要 】

BackgroundThe optimal duration of immune checkpoint blockade (ICB) therapy is not well established. Active residual disease is considered prohibitive for treatment discontinuation and its detection by diagnostic CT imaging is limited. Here, we set out to determine the potential added value of 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) to identify patients at higher risk of relapse following discontinuation of ICB in advanced melanoma.MethodsMetastatic melanoma patients who discontinued ICB were identified retrospectively. Eligible patients received FDG-PET and diagnostic CT within four months of ICB discontinuation. We defined morphologic response using RECIST v1.1. Complete metabolic response (CMR) was defined as uptake in tumor lesions below background, whereas any site of residual, FDG-avid disease was rated as non-CMR. The primary endpoint was time to progression (TTP) after therapy discontinuation stratified by morphologic and metabolic imaging response using Kaplan–Meier estimates and log-rank test.ResultsThiry-eight patients were eligible for this analysis. Median follow-up was 37.3 months since ICB discontinuation. Median TTP in the overall cohort was not reached. A greater proportion of patients were rated as CMR in PET (n = 34, 89.5%) as compared to complete response (CR) in CT (n = 13, 34.2%). Median TTP was reached in patients with non-CMR (12.7 months, 95%CI 4.4-not reached) but not for patients with CMR (log-rank: p < 0.001). All patients with complete response by CT had CMR by PET. In a subset of patients excluding those with complete response by CT, TTP remained significantly different between CMR and non-CMR (log-rank: p < 0.001).ConclusionAdditional FDG-PET at time of discontinuation of ICB therapy helps identify melanoma patients with a low risk of recurrence and favourable prognosis compared to CT imaging alone. Results may have clinical relevance especially for patients with residual tumor burden.

【 授权许可】

CC BY