Transforming Cancer Diagnosis and Treatment with Cerium/Lanthanum-134
Image courtesy of Bobba, K.N., et al., Evaluation of cerium/lanthanum-134 as a PET imaging theranostic pair for 225Ac alpha radiotherapeutics. Journal of Nuclear Medicine 64, 7 (2023). Radiopharmaceuticals based on cerium/lanthanum-134 have promise for prostate cancer imaging and therapy. At right, tumors show high tumor uptake of cerium-134. At left, a comparison of cerium-134 and actinium-225 shows a similar pattern of uptake in most tissues (note the tumor tissue on the leg).
Theranostics is an emerging field combining imaging and therapy, allowing a personalized approach to treating cancer and other diseases. The use of theranostics in nuclear medicine has been shown to be highly effective in treating certain types of cancer, such as neuroendocrine tumors and prostate cancer. Research has shown that actinium-225 (half-life = 9.9 days) based targeted alpha therapies are effective in treating metastatic castration-resistant prostate cancers, significantly improving patient survival and disease remission. Unfortunately, localization and accurate dose estimation are a considerable challenge due to the lack of imaging isotopes with similar half-life and chemistry to actinium-225. Recently, researchers developed a cerium/lanthanum-134 pair as an imaging surrogate to overcome these challenges.
In this study, supported by the DOE Isotope Program and the Department of Defense, researchers from the University of California, San Francisco and the University of Virginia developed a robust cerium-134 radiolabeling methodology using the chelators Macropa and DOTA. They also applied the optimized method for prostate cancer targeting agents PSMA-617 and antibody YS5. Encouragingly, the localization of cerium/lanthanum-134 Macropa-PEG4-YS5 demonstrated identical distribution in most tissues along with tumors except for the liver and spleen. The researchers believe this is the first report of a comprehensive study comparing the chemistry and localization of Ce-134 and Ac-225, starting from chelators to tumor-targeting agents. These studies support the development of Ce-134 radiopharmaceuticals for cancer imaging as a companion paired with alpha particle radiotherapeutics.