68Ga-NY104 PET/CT for detecting suspected metastatic or recurrent clear cell renal cell carcinoma after nephrectomy: a prospective, single-center, single-arm imaging trial

Carbonic anhydrase-IX (CAIX) has emerged as a highly attractive molecular target for imaging clear cell renal cell carcinoma (ccRCC). This study was designed to evaluate a small molecular CAIX-targeting PET tracer, 68 Ga-NY104, in the identification of patients with metastasis/recurrence ccRCC suspicion after nephrectomy. Among the 42 enrolled patients, 32 patients were confirmed to have metastatic/recurrent ccRCC. 68 Ga-NY104 PET/CT demonstrated a sensitivity of 94% (95% CI: 80% − 98%) and specificity of 80% (95% CI: 49% − 94%) at patient-level. Inter-reader agreement was substantial (Fleiss’ κ = 0.70, P < 0.001). Notably, the scan identified 25 previously unknown disease regions in 12 patients. 68 Ga-NY104 exhibited high uptake in ccRCC lesions, with a mean SUVmax of 15.8 ± 13.6 and tumor-to-background ratio of 11.5 ± 13.0. A significant difference in tracer uptake was observed between lesions with positive and negative CAIX immunohistochemical staining results (SUVmax, 24.5 ± 13.3 vs. 2.0 ± 0.4, P < 0.05). 68 Ga-NY104 PET/CT demonstrates promising diagnostic efficacy and substantial inter-reader agreement in patients with metastasis/recurrence ccRCC suspicion after nephrectomy.