RESUMO
Objective:To investigate the preparation methods and quality control of 177Lu-labeled radiopharmaceuticals, and conduct preliminary clinical application research. Methods:177Lu-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)- D-Phe1-Tyr3-octreotide (TOC) and 177Lu-prostate specific membrane antigen (PSMA)-I&T were labeled by manual labeling and automatic labeling, respectively. Factors such as the amount of precursor and nuclide, reaction temperature, pH value, reaction time, labeling yield and specific activity were investigated. Quality control of the products were carried out, such as clarity, pH value, sterility, bacterial endotoxin and stability in vitro. 177Lu-PSMA-I&T was applied to the treatment of prostate cancer patients, and the efficacy was evaluated by SPECT/CT imaging. Paired t test was used to analyze the data. Results:The amount of precursor and nuclide, reaction temperature, pH value and reaction time of the two methods were basically the same, both with high yield and specific activity. The yield of 177Lu-DOTA-TOC automatic labeling was significantly higher than that of manual labeling (99.2±0.4)% vs (95.3±1.5)% ( t=7.17, P<0.001), and the specific activity were (91.6±13.7) vs (89.1±13.2) GBq/μmol. The yield of 177Lu-PSMA-I&T automatic labeling was also significantly higher than that of manual labeling (99.6±0.3)% vs (95.7±1.3)% ( t=8.24, P<0.001), and the specific activity were (96.1±14.3) vs (93.2±13.8) GBq/μmol. The labeled products were colorless clear solution with pH value of 6.5-7.0. The sterility and bacterial endotoxin met the requirements. The radiochemical purity of the labeled products was more than 95% after 48 h, which showed good stability. The clinical application of 177Lu-PSMA-I&T in patients with prostate cancer showed that both primary and metastatic lesions had good uptake. Conclusions:The labeling of 177Lu radiopharmaceuticals is simple and has high yield and stability. The application of automatic labeling can simplify the process, improve the yield and reduce irradiation.