This study aims to quantify the biodistribution of Al18F-NOTA-Pentixafor (1 8 F-CXCR4) using PET/CT imaging, establish reference ranges of organ radiotracer uptake, characterize uptake patterns in benign lesions, and evaluate radiation dosimetry. In this retrospective study, we analyzed 1 8 F-CXCR4 PET/CT data from 51 patients, with radiotracer uptake in organs and benign lesions quantified using SUVmax and SUVmean. Biodistribution differences according to sex, age, and gallbladder excretion status were evaluated. In addition, three postmenopausal females underwent serial whole-body PET/CT imaging during the rapid distribution, equilibrium, and clearance phases of 1 8 F-CXCR4, and time–activity curves were used to calculate organ-absorbed doses based on the ICRP adult female model. Physiological 1 8 F-CXCR4 radiotracer uptake was highest in the urinary tract, biliary system, and uterus (SUVmax ≥ 4.6), moderate in the myocardium, lungs, and pancreas (SUVmax 1.30–3.16), and lowest in the brain, spinal cord, and skeletal muscle (SUVmax ≤ 0.84). No significant sex differences were found for either SUVmax or SUVmean (P > 0.05), except for higher pancreatic SUVmean in males (P = 0.01) and higher lung and blood-pool SUVmean in females (P = 0.02). Younger patients exhibited higher biliary SUVmax than older patients (P = 0.04). Although fasted patients showed increased gallbladder tracer accumulation, the difference was not statistically significant (P = 0.06). Benign lesions demonstrated a wide range of radiotracer uptake (SUVmax 1.25–6.22). The effective dose of 1 8 F-CXCR4 was estimated to be 2.02E-02 mSv/MBq, with the kidneys receiving the highest absorbed dose. 18F-CXCR4 exhibits a stable physiological biodistribution profile minimally influenced by sex or age, thereby enabling the establishment of reliable diagnostic reference ranges. Analysis of CXCR4 expression in benign lesions supports basic research and diagnosis/treatment of related diseases, while confirming dosimetric safety. The trial is retrospectively registered at the Chinese Clinical Trial Registry (ChiCTR) (registration number: ChiCTR2400090595, registration date: 2024–10-09).
Li et al. (Sat,) studied this question.