BACKGROUND: Ga]Ga-FAPI-04 PET/CT in these two subtypes of IgG4-RD. RESULTS: Ga]Ga-FAPI-04 than the fibrotic subtype (SUVmax, 16.59 ± 7.06 vs. 12.08 ± 4.65, P = 0.007; TBR, 14.50 ± 7.98 vs. 10.32 ± 5.08, P = 0.036). The TLU and MLV were also significantly higher in the proliferative subtype (median IQR, TLU, 861.40 340.40, 2465.48 vs. 419.15 244.98, 657.90, P = 0.020; MLV, 177.11 79.99, 503.94 vs. 107.98 54.10, 163.24, P = 0.029). The pancreato-hepato-biliary disease demonstrated the highest SUVmax and TBR, followed by fibrosis/periaortitis, head-and-neck disease, and others involvements (P < 0.05). Lymph nodes demonstrated the lowest SUVmax and TBR among all disease. The relapse-free survival curve did not show significant difference between proliferative and fibrotic patients (P = 0.56). Patients with TBR ≥ 16.3 or SUVmean ≥ 5 had significantly shorter relapse-free survival than those below these thresholds (TBR, 39.7 months vs. not reached, P = 0.0078, hazard ratio = 5.74 95%CI, 1.58-20.80; SUVmean, 39.0 months vs. not reached, P = 0.019, hazard ratio = 4.36 95%CI, 1.27-14.94). CONCLUSION: Ga]Ga-FAPI-04 PET/CT derived parameters is predictive of relapse-free survival in patients with IgG4-RD. TRIAL REGISTRATION: ClinicalTrials. NCT04125511 (Characterizing IgG4RD With 68GaFAPI PET/CT). Registered 14 October 2019, https//clinicaltrials.gov/study/NCT04125511?cond=NCT04125511&rank=1.
Liu et al. (Wed,) studied this question.