Synthesis and Preclinical Characterization of [18F]FPBZA: A Novel PET Probe for Melanoma

Abstract EN

Introduction.

Benzamide can specifically bind to melanoma cells.

A 18F-labeled benzamide derivative, [18F]N-(2-diethylaminoethyl)-4-[2-(2-(2-fluoroethoxy) ethoxy)ethoxy]benzamide ([18F]FPBZA), was developed as a promising PET probe for primary and metastatic melanoma.

Methods.

[18F]FPBZA was synthesized via a one-step radiofluorination in this study.

The specific uptake of [18F]FPBZA was studied in B16F0 melanoma cells, A375 amelanotic melanoma cells, and NB-DNJ-pretreated B16F0 melanoma cells.

The biological characterization of [18F]FPBZA was performed on mice bearing B16F0 melanoma, A375 amelanotic melanoma, or inflammation lesion.

Results.

[18F]FPBZA can be prepared efficiently with a yield of 40–50%.

The uptake of [18F]FPBZA by B16F0 melanoma cells was significantly higher than those by A375 tumor cells and NB-DNJ-pretreated B16F0 melanoma cells.

B16F0 melanoma displayed prominent uptake of [18F]FPBZA at 2 h (7.81±0.82 %ID/g), compared with A375 tumor and inflammation lesion (3.00±0.71 and 1.67±0.56 %ID/g, resp.).

[18F]FPBZA microPET scan clearly delineated B16F0 melanoma but not A375 tumor and inflammation lesion.

In mice bearing pulmonary metastases, the lung radioactivity reached 4.77±0.36 %ID/g at 2 h (versus 1.16±0.23 %ID/g in normal mice).

Conclusions.

Our results suggested that [18F]FPBZA PET would provide a promising and specific approach for the detection of primary and metastatic melanoma lesions.