PT  - JOURNAL ARTICLE
AU  - Shi, Binyu
AU  - Zhang, You
AU  - Wu, Shuo
AU  - Xu, Dongsheng
AU  - Wu, Qianyun
AU  - Jia, Wenzhi
AU  - An, Shuxian
AU  - Wang, Cheng
AU  - Bai, Yongrui
AU  - Liu, Jianjun
AU  - Zhou, Junjun
AU  - Wei, Weijun
TI  - CD70-Targeted [<sup>18</sup>F]RCCB6 Immuno-PET/CT Imaging in Patients with Nasopharyngeal Carcinoma: A Proof-of-Concept Study
AID  - 10.2967/jnumed.125.269585
DP  - 2025 Apr 30
TA  - Journal of Nuclear Medicine
PG  - jnumed.125.269585
4099  - http://jnm.snmjournals.org/content/early/2025/04/30/jnumed.125.269585.short
4100  - http://jnm.snmjournals.org/content/early/2025/04/30/jnumed.125.269585.full
AB  - CD70 has emerged as a promising biomarker for nasopharyngeal carcinoma (NPC). This study investigated CD70 expression patterns in NPC specimens and evaluated the diagnostic potential of CD70-targeted [18F]RCCB6 immuno-PET/CT in patients with NPC. Methods: CD70 expression was analyzed in 80 archived NPC specimens and correlated with clinical and pathologic features. Using [18F]RCCB6, a single-domain antibody–derived tracer specific for human CD70, the diagnostic efficacy of [18F]RCCB6 immuno-PET/CT was assessed in 25 patients with NPC and compared with that of 18F-FDG PET/CT. Results: CD70 was positively expressed in 72 (90%) of 80 NPC specimens, with expression levels strongly correlated with Epstein-Barr virus (EBV) titers (rs = 0.437; P < 0.001) and N-staging (P = 0.006). In all 15 patients with early-stage NPC, [18F]RCCB6 immuno-PET/CT achieved a 100% detection rate of the primary tumor and a 93% detection rate (75/81) of local lymph node metastasis. [18F]RCCB6 uptake correlated well with CD70 expression. In a head-to-head comparison, [18F]RCCB6 demonstrated higher sensitivity than did 18F-FDG in detecting lymph node metastasis (100% [58/58] vs. 90% [52/58], respectively; P = 0.031), and equivalent detection abilities for primary lesions and most distant metastases (100%). Notably, [18F]RCCB6 immuno-PET/CT demonstrated better evaluation of skull-base invasion with a clear border and bone metastases, as indicated by its higher uptake compared with 18F-FDG (7.25 vs. 5.95; P = 0.025). Conclusion: CD70 is a potent biomarker for NPC. [18F]RCCB6 immuno-PET/CT provides precise mapping of CD70 expression and enhances the diagnosis of primary, metastatic, and recurrent NPCs, outperforming 18F-FDG in detecting skull-base invasion and metastases.