Prognostic value of the dual-tracer PET score (NETPET) in neuroendocrine tumors with [²²⁵Ac]Ac-DOTATATE therapy

To investigate the association between baseline NETPET score and prognosis in patients with neuroendocrine tumors (NETs) receiving [²²⁵Ac]Ac-DOTATATE therapy.

This retrospective study included patients with NETs treated with [²²⁵Ac]Ac-DOTATATE between November 2021 and March 2025. All patients underwent [¹⁸F]F-FDG and [⁶⁸Ga]Ga-DOTATATE PET within one week before treatment. Up to 10 representative lesions per patient were selected for NETPET scoring. The primary endpoint was progression-free survival (PFS). The relationship between NETPET score and PFS was evaluated using Kaplan-Meier analysis and univariate/multivariate Cox proportional hazards models.

Forty-eight patients were enrolled (P1: n = 14, P2-4: n = 22, P5: n = 12). The P1 group achieved significantly better PFS than the P2-4 and P5 groups (2-year PFS rates: 0.83 vs. 0.32 vs. 0.10; log-rank P < 0.0001). Univariate analysis revealed a significant association of NETPET score with PFS (P2-4 vs. P1: HR = 7.07, P = 0.009; P5 vs. P1: HR = 17.0, P < 0.001). Multivariate analysis demonstrated the NETPET score to be independently associated with PFS (P2-4 vs. P1: P = 0.003; P5 vs. P1: P < 0.001). Its predictive value for overall survival was limited (P > 0.05).

The NETPET score was independently associated with progression-free survival and may serve as a potential imaging biomarker for pretreatment risk stratification in NET patients receiving [²²⁵Ac]Ac-DOTATATE therapy.