89Zr-DFO-TOC and 89Zr-DFO-TATE compared for enhanced SSTR PET dosimetry in neuroendocrine tumors.

Neuroendocrine tumors (NETs) are a heterogeneous group of malignancies with high morbidity and mortality, necessitating early and accurate diagnosis. A key feature is the overexpression of somatostatin receptors (SSTRs), exploited by radiolabeled somatostatin analogues for PET imaging. While FDA-approved SSTR PET tracers exist, their clinical utility is limited by short half-lives or production constraints. 89Zr (t1/2 = 3.27 days) offers potential for extended imaging, improved tumor-to-background contrast, and more accurate pretherapy dosimetry, addressing current tracer limitations.

This preclinical study performed a head-to-head in vivo comparison of two 89Zr-labeled somatostatin analogues, [89Zr]Zr-DFO-TATE and [89Zr]Zr-DFO-TOC, for PET imaging of SSTR-positive NETs. The investigation included in vivo PET imaging, ex vivo biodistribution analysis, and internal radiation dosimetry assessments. The primary objective was to evaluate the performance of these agents to advance precision diagnostics and improve therapeutic planning for NET patients, particularly those undergoing [177Lu]Lu-DOTA-TATE therapy. Specific animal models, doses, or sample sizes were not detailed in the abstract.