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

Purpose To compare the potential efficiency of [ 68 Ga]Ga-LNC1007 with 2-[ 18 F]FDG/[ 68 Ga]Ga-PSMA PET/CT for detecting renal cell carcinoma (RCC) and to explore parameters derived from [ 68 Ga]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 (SUV max ), mean SUV (SUV mean ), 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 [ 68 Ga]Ga-LNC1007 PET/CT showed a higher detection rate for primary lesions than 2-[ 18 F]FDG and [ 68 Ga]Ga-PSMA (LNC1007 vs. FDG: 13/17 vs. 4/17, P = 0.005; LNC1007 vs. PSMA: 9/11 vs. 6/11, P = 0.361). [ 68 Ga]Ga-LNC1007 PET/CT showed higher SUV max (6.6 vs. 3.7, P = 0.005), SUV mean (4.1 vs. 2.3, P = 0.001) and TBR (2.6 vs. 1.7, P = 0.011) compared with 2-[ 18 F]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 [ 68 Ga]Ga-PSMA PET/CT. SUV max and TBR derived from [ 68 Ga]Ga-LNC1007 PET/CT could effectively differentiate WHO/ISUP grade (3–4 vs. 1–2) and adverse pathological features (positive vs. negative) (SUV max : 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 SUV max was positively correlated with the FAP expression, integrin α v β 3 expression and the total expression of FAP and integrin α v β 3 ( r = 0.577, P = 0.006, r = 0.701, P < 0.001, and r = 0.702, P < 0.001, respectively). Conclusion [ 68 Ga]Ga-LNC1007 is a promising tracer for RCC imaging and can effectively identify aggressive pathological characteristics of RCC.