The fractionated therapy group exhibited significantly lower tumor volumes and did not exceed 200% of the initial tumor volume. 68Ga-labeled sdAbs enabled high-contrast PET imaging and 177Lu-labeled sdAbs, particularly in fractionated regimens, effectively delayed tumor progression and were well tolerated, supporting further clinical translation.
Squaric acid derivatization synergistically elevates affinity, hydrophilicity, and intratumoral residence while preserving safety, establishing 68Ga/177Lu-FAP2286-SA as a clinically translatable, next-generation theranostic pair for FAP-positive malignancies.