%0 Journal Article
%T A Novel Melanin-Targeted 18F-PFPN Positron Emission Tomography Imaging for Diagnosing Ocular and Orbital Melanoma.
%A Wang Y
%A Wang X
%A Zhang J
%A Zhang X
%A Cheng Y
%A Jiang F
%J Korean J Radiol
%V 25
%N 8
%D 2024 Aug 10
%M 39028010
%F 7.109
%R 10.3348/kjr.2024.0243
%X <B>OBJECTIVE: </B>18F-N-(2-(Diethylamino)ethyl)-5-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy) picolinamide (18F-PFPN) is a novel positron emission tomography (PET) probe designed to specifically targets melanin. This study aimed to evaluate the diagnostic feasibility of 18F-PFPN in patients with ocular or orbital melanoma.<BR><B>METHODS: </B>Three patients with pathologically confirmed ocular or orbital melanoma (one male, two females; age 41-59 years) were retrospectively reviewed. Each patient underwent comprehensive 18F-PFPN and 18F-fluorodeoxyglucose (18F-FDG) PET scans. The maximum standardized uptake value (SUVmax) of the lesion and the interference caused by background tissue were compared between 18F-PFPN and 18F-FDG PET imaging. In addition, the effect of intrinsic pigments in the uvea and retina on the interpretation of the results was examined. The contralateral non-tumorous eye of each patient served as a control.<BR><B>RESULTS: </B>All primary tumors (3/3) were detected using 18F-PFPN PET, while only two primary tumors were detected using 18F-FDG PET. Within each lesion, the SUVmax of 18F-PFPN was 2.6 to 8.3 times higher than that of 18F-FDG. Regarding the quality of PET imaging, the physiological uptake of 18F-FDG PET in the brain and periocular tissues limited the imaging of tumors. However, 18F-PFPN PET minimized this interference. Notably, intrinsic pigments in the uvea and retina did not cause abnormal concentrations of 18F-PFPN, as no anomalous uptake of 18F-PFPN was detected in the healthy contralateral eyes.<BR><B>CONCLUSIONS: </B>Compared to 18F-FDG, 18F-PFPN demonstrated higher detection rates for ocular and orbital melanomas with minimal interference from surrounding tissues. This suggests that 18F-PFPN could be a promising clinical diagnostic tool for distinguishing malignant melanoma from benign pigmentation in ocular and orbital melanomas.