Our purpose was to investigate the prognostic value of 18F-FDG PET/CT parameters in melanoma patients before beginning therapy with antibodies to the programmed cell death 1 receptor (anti-PD-1). Methods: Imaging parameters including SUVmax, metabolic tumor volume, and the ratio of bone marrow to liver SUVmean (BLR) were measured from baseline PET/CT in 92 patients before the start of anti-PD-1 therapy. The association with survival and imaging parameters combined with clinical factors was evaluated. Clinical and laboratory data were compared between the high-BLR group (>median) and the low-BLR group (≤median). Results: Multivariate analyses demonstrated that BLR was an independent prognostic factor for progression-free and overall survival (P = 0.017 and P = 0.011, respectively). The high-BLR group had higher white blood cell counts and neutrophil counts and a higher level of C-reactive protein than the low-BLR group (P < 0.05). Conclusion: Patients with a high BLR were associated with poor progression-free and overall survival, potentially explained by evidence of systemic inflammation known to be associated with immunosuppression.
Keywords: 18F-FDG; PET/CT; bone marrow uptake; immunotherapy; melanoma.
© 2021 by the Society of Nuclear Medicine and Molecular Imaging.