68Ga-NODAGA-LM3: A Promising Tool for Evaluating Small Cell Lung Cancer

In a recent presentation at the 2025 Society of Nuclear Medicine and Molecular Imaging Annual Meeting, researchers unveiled promising findings regarding the use of 68Ga-NODAGA-LM3 in evaluating responses in patients with small cell lung cancer (SCLC). This study, led by Dr. Meixi Liu from the Department of Nuclear Medicine at Peking Union Medical College Hospital in Beijing, China, highlights the potential of 68Ga-NODAGA-LM3 PET/CT imaging to detect bone and brain lesions more effectively than the traditional 18F-FDG imaging method.

The study involved a cohort of ten patients diagnosed with SCLC, and results indicated a 100% patient-level detection rate for both imaging techniques. However, there were notable differences in regional detection rates, with 68Ga-NODAGA-LM3 showing a preference for identifying bone and brain lesions, while 18F-FDG was more effective in detecting lymph node and abdominal metastases. Dr. Liu mentioned that inter-lesion heterogeneity was observed in six out of ten patients, indicating variability in tracer distribution across tumors.

This research is particularly significant given the dire prognosis associated with SCLC, which has a 5-year survival rate of merely 5% and a median overall survival of only 2 to 4 months. Dr. Liu emphasized the urgent need for innovative theranostic approaches in managing this aggressive cancer type, as conventional second-line therapies following the initial chemotherapy and anti-PD-1 treatments remain limited.

The study also explored the eligibility for peptide receptor radionuclide therapy (PRRT) based on imaging results. The eligibility rates varied significantly depending on the criteria used: 90% based on the hottest maximum standard uptake value (SUVmax) above the liver, 60% for mean SUVmax above the liver, and 40% for 80% of lesions with SUVmax above the liver. These findings underscore the importance of establishing standardized criteria for selecting candidates for PRRT in SCLC patients.

Dr. Liu and her team also noted that approximately 80% of SCLC patients exhibit an average SUVmax higher than the liver, which could increase their candidacy for PRRT. The ongoing analysis of heterogeneity between imaging results raises critical questions about how this variability affects treatment response and patient management.

In conclusion, the findings from this study suggest that 68Ga-NODAGA-LM3 PET/CT could serve as a valuable modality for evaluating treatment responses in SCLC, particularly in detecting bone and brain lesions. This advancement may lead to more personalized treatment strategies and improved outcomes for patients facing this challenging disease. As research continues, the oncology community remains hopeful for more effective interventions in the fight against small cell lung cancer.

### References 1. Liu M, Zhang Y, Yan X, et al. Staging, heterogeneity analysis, and early treatment response evaluation based on 68Ga-NODAGA-LM3 and 18F-FDG PET/CT in small cell lung cancer patients. Presented at SNMMI 2025; June 21-24, 2025; New Orleans, LA. 2. Kersting D, Sandach P, Sraieb M, et al. 68Ga-SSO-120 PET for initial staging of small cell lung cancer patients: a single-center retrospective study. J Nucl Med. 2023;64(10):1540-1549. doi:10.2967/jnumed.123.265664.