Posttreatment ⁶⁸Ga-FAP-2286 PET/CT Parameters for Response and Survival Assessment After ¹⁷⁷Lu-FAP-2286 Radioligand Therapy in Advanced Solid Tumors.
Larger rise in PET tracer uptake after therapy linked to over 5-fold progression risk
Posttreatment ⁶⁸Ga-FAP-2286 PET/CT Parameters for Response and Survival Assessment After ¹⁷⁷Lu-FAP-2286 Radioligand Therapy in Advanced Solid Tumors.
Fibroblast activation protein (fibroblast activation protein) is highly expressed in cancer-associated fibroblasts and represents an emerging target for radioligand therapy (radioligand therapy).
This study aimed to evaluate treatment outcomes of ¹⁷⁷Lu-FAP-2286 and to investigate whether changes in quantitative parameters on ⁶⁸Ga-FAP-2286 PET/CT are associated with treatment response and survival in patients with advanced solid tumors.
In this single-center retrospective study, patients with advanced solid tumors who completed 2 cycles of ¹⁷⁷Lu-FAP-2286 therapy and underwent both baseline and posttreatment ⁶⁸Ga-FAP-2286 PET/CT (8-16 wk after therapy) were included.
bigger tracer uptake rise after therapy meant over 5 times higher progression risk
Thirty patients (median age, 65 y; range, 23-78 y) completed 2 cycles of ¹⁷⁷Lu-FAP-2286 therapy.
According to RECIST 1.1, partial response, stable disease, and progressive disease occurred in 6 (20.0%), 11 (36.7%), and 13 (43.3%) patients, respectively.
Standardized uptake value and total tumor volume decreased in 46.7% of patients. Δstandardized uptake value demonstrated moderate discrimination for RECIST-defined PD (AUC 0.72, P=0.04).
Median OS was not reached in the Δstandardized uptake value <30% group compared with 9.8 months in the Δstandardized uptake value ≥30% group (log-rank P=0.003).
In patients with advanced solid tumors treated with 2 cycles of ¹⁷⁷Lu-FAP-2286, posttreatment changes in standardized uptake value on ⁶⁸Ga-FAP-2286 PET/CT were associated with treatment response and survival, suggesting potential utility as an imaging biomarker for early response assessment and prognostic stratification.