RT Journal Article SR Electronic T1 CD70-Targeted Immuno-PET/CT Imaging of Clear Cell Renal Cell Carcinoma: A Translational Study JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1891 OP 1898 DO 10.2967/jnumed.124.268509 VO 65 IS 12 A1 Zhou, Xiang A1 Wu, Qianyun A1 Zhai, Wei A1 Zhang, You A1 Wu, Yanfei A1 Cao, Min A1 Wang, Cheng A1 Guan, Yihui A1 Liu, Jianjun A1 Xie, Fang A1 Wei, Weijun YR 2024 UL http://jnm.snmjournals.org/content/65/12/1891.abstract AB The diagnosis and surveillance of clear cell renal cell carcinoma (ccRCC) remains a clinical challenge. The high and specific expression of the cluster of differentiation 70 (CD70) in ccRCC makes it a potential diagnostic and therapeutic target. Methods: We detected and analyzed CD70 expression in various renal cell carcinomas (RCCs) and normal kidneys using immunohistochemical staining. Two novel CD70-specific single-domain antibodies, RCCB3 and RCCB6, were produced and labeled with 68Ga to develop radiotracers. We performed immuno-PET/CT imaging with [68Ga]Ga-NOTA-RCCB3 and [68Ga]Ga-NOTA-RCCB6 in subcutaneous ccRCC patient–derived xenograft models. We recruited 8 RCC patients in a pilot clinical trial (ClinicalTrials.gov identifier: NCT06148220) to evaluate the diagnostic utility of [68Ga]Ga-NOTA-RCCB3 and [68Ga]Ga-NOTA-RCCB6 immuno-PET/CT. Results: Expression of CD70 is associated with sex, tumor differentiation, tumor thrombus, necrosis, distant metastasis, and overall survival of RCC patients. RCCB3 and RCCB6 had high affinities for recombinant human CD70. Immuno-PET/CT imaging with [68Ga]Ga-NOTA-RCCB3 and [68Ga]Ga-NOTA-RCCB6 rapidly visualized subcutaneous ccRCC with clarity. Tumor uptake of [68Ga]Ga-NOTA-RCCB6 was significantly reduced after the blockade of CD70. [68Ga]Ga-NOTA-RCCB6 PET/CT in ccRCC patients outperformed traditional 18F-FDG PET/CT in specifically identifying CD70-positive ccRCC metastases. Conclusion: CD70-targeted immuno-PET/CT imaging with [68Ga]Ga-NOTA-RCCB6 or [68Ga]Ga-NOTA-RCCB3 is a precise and superior method for evaluating tumor burden and suspected metastases in ccRCC patients. This advancement in imaging technology has the potential to improve the clinical decision-making process for this patient cohort significantly.