A prospective head-to-head comparison of 18F-NYM005 PET/CT and 18F-FDG PET/CT in diagnosing renal cell carcinoma

This study aimed to compare the diagnostic efficacy of ¹⁸F-NYM005 PET/CT and ¹⁸F-FDG PET/CT in patients with renal cell carcinoma (RCC).

Patients with renal tumors were prospectively enrolled in the study (ClinicalTrials.gov: NCT06916624). They were divided into three groups: Group I, patients with a primary renal tumor who were scheduled for surgery; Group II, patients with CAIX expression proven by histopathology after surgery who were suspicious of metastatic RCC; and Group Tyrosine Kinase Inhibitors (TKI), RCC patients who received TKI treatment. Paired ¹⁸F-NYM005 and ¹⁸F-FDG PET/CT scans were performed. Per-lesion diagnostic efficacy and uptake activity of the two tracers in primary tumors, lymph nodes, and distant metastases were compared.

Thirty-eight patients (median age, 61.5 y; 32 males) were enrolled, including 12 patients in Group I, 19 patients in Group II, and 7 patients in Group TKI. For detecting primary and metastatic lesions in Group I and Group II, ¹⁸F-NYM005 PET/CT demonstrated a higher accuracy (93.86% vs.70.50%, P < 0.001) and a higher specificity (96.95% vs.61.58%, P < 0.001) than ¹⁸F-FDG PET/CT, and no significant difference in sensitivity was observed between the two scans (88.80% vs. 85.06%, P = 0.306). In quantitative analysis, no significant difference in SUVmax was found between the¹⁸F-NYM005 PET/CT and ¹⁸F-FDG PET/CT for primary tumors (14.56 ± 10.31 vs. 9.96 ± 5.56, P = 0.233) and metastatic lymph nodes (5.99 [4.12, 31.71] vs. 4.06 [3.18, 13.01], P = 0.754), and the SUVmax of the distant metastases was higher (7.92 [2.92, 13.40] vs. 2.49 [1.12, 5.37], P < 0.001) in ¹⁸F-NYM005 PET/CT than that in ¹⁸F-FDG PET/CT. In Group TKI, the SUVmax of the primary and metastatic lesions was lower (1.59 [1.16, 3.25] vs. 6.76 [5.11, 13.01], P < 0.001) in ¹⁸F-NYM005 PET/CT than that in ¹⁸F-FDG PET/CT.

¹⁸F-NYM005 PET/CT offers a high diagnostic efficacy for detecting primary tumors and distant metastases in patients with RCC, while it might be of limited value in identifying metastatic lymph nodes.