Melanin-targeted [18F]-PFPN PET imaging for prognosticating patients with melanoma

Purpose Positron emission tomography (PET) using [F-18]-PFPN, a melanin-targeted imaging tracer, has excellent diagnostic performance in patients with melanoma. This study aimed to investigate its value in prognostication and determine predictors of progression-free survival (PFS) and overall survival (OS).Methods We reviewed melanoma patients who underwent [F-18]-PFPN and [F-18]-FDG PET from February 2021 to July 2022. Clinical characteristics, follow-up data, and the following [F-18]-PFPN PET parameters were recorded: maximum standardized uptake value (SUVmax), whole-body melanotic tumoral volume (WBMTV), and whole-body total lesion melanin (WBTLM). Receiver operating characteristic (ROC), Kaplan-Meier and Cox regression analyses were performed.Results Seventy-six patients (47 men and 29 women; mean age, 57.99 +/- 10.72 years) were included for analysis. Median follow-up was 12.0 months (range: 1-22 months). Eighteen patients died and 38 experienced progression. Median OS was 17.60 months (95% confidence interval, 15.89-19.31). In the ROC analysis, [F-18]-PFPN PET parameters were superior to those of [F-18]-FDG PET in prognosticating death and disease progression. PFS and OS were significantly better in patients with lower SUVmax, WBMTV, and WBTLM on [F-18]-PFPN PET (log-rank, P < 0.05). In the univariate analyses, distant metastasis, SUVmax, WBMTV, and WBTLM were significantly associated with cumulative incidence of PFS and OS (P < 0.05). In the multivariate analysis, SUVmax was an independent predictor of PFS and OS.Conclusions [F-18]-PFPN PET has a role in prognostication of melanoma patients. Patients with higher [F-18]-PFPN SUVmax have worse prognosis.