[⁶⁸Ga]Ga-LNC1007 PET/CT in the evaluation of renal cell carcinoma: comparison with 2-[¹⁸F]FDG/[⁶⁸Ga]Ga-PSMA PET/CT

Purpose To compare the potential efficiency of [ 68Ga]Ga-LNC1007 with 2-[18F]FDG/[68Ga]Ga-PSMA PET/CT for detecting renal cell carcinoma (RCC) and to explore parameters derived from [ 68Ga]Ga-LNC1007 PET/ CT for discriminating pathological characteristics in RCC. Methods Twenty-five RCC patients confirmed by pathology were enrolled in this prospective study. The maximum standardized uptake value ( SUVmax), mean SUV (SUVmean), gross tumor volume (GTV) and total lesion-tracer (TL-tracer) of lesions were calculated from the corresponding PET/CT images. Pathological characteristics included World Health Organization/ International Society of Urological Pathology (WHO/ISUP) grade and adverse pathological features (tumor necrosis or sarcomatoid or rhabdoid feature). Results [68Ga]Ga-LNC1007 PET/CT showed a higher detection rate for primary lesions than 2-[18F]FDG and [ 68Ga]GaPSMA (LNC1007 vs. FDG: 13/17 vs. 4/17, P = 0.005; LNC1007 vs. PSMA: 9/11 vs. 6/11, P = 0.361). [ 68Ga]Ga-LNC1007 PET/CT showed higher SUVmax (6.6 vs. 3.7, P = 0.005), SUVmean (4.1 vs. 2.3, P = 0.001) and TBR (2.6 vs. 1.7, P = 0.011) compared with 2-[18F]FDG PET/CT, and it also showed higher TBR (2.9 vs. 0.5, P = 0.003), TBR- delay ( 2.8 vs. 0.3, P = 0.003), GTV (84.1 vs. 42.9, P = 0.003) and TL-tracer (442.7 vs. 235.8, P = 0.008) compared with [ 68Ga]Ga- PSMA PET/CT. SUVmax and TBR derived from [ 68Ga]Ga-LNC1007 PET/CT could effectively differentiate WHO/ISUP grade (3-4 vs. 1-2) and adverse pathological features ( positive vs. negative) ( SUVmax: AUC 0.81, P = 0.04; AUC 0.80, P = 0.033; TBR: AUC 0.84, P = 0.026; AUC 0.85, P = 0.014). The SUVmax was positively correlated with the FAP expression, integrin av ss 3 expression and the total expression of FAP and integrin av ss 3 (r = 0.577, P = 0.006, r = 0.701, P < 0.001, and r = 0.702, P < 0.001, respectively). Conclusion [68Ga]Ga-LNC1007 is a promising tracer for RCC imaging and can effectively identify aggressive pathological characteristics of RCC.