Project Summary/Abstract Current radioembolic Y-90 microspheres have been generally recognized as the state-of-the-art for treating primary and metastatic liver tumors. However, the clinical results vary vastly due to the lack of accurate diagnostic imaging for dose and treatment planning and the lack of image guidance and dose conformation during the administration of Y-90 microspheres. The investigation team has established the feasibility of using PET imaging agent alone or along with Y-90. All key feasibilities have been demonstrated as proposed in Phases I & II. This proposed Phase IIB research focuses on the preparation of radioembolic Y- 90 microspheres at therapeutic levels of Y-90 with enhanced personnel safety, and the research also focuses on the calibration of Y-90 dose distribution that is critical and practical for real-time Y-90 dosimetry to improve much desired efficacy. The objectives of this proposed Phase IIB research are (1) to establish a microfabrication process for on-demand production of PET emitting microspheres using commercially viable glass compositions, (2) to reliably produce low-cost Y-90 radioisotope, (3) to assess biocompatibility and biological risks to gain FDA acceptance for a human clinical investigation, and (4) to demonstrate clinical utility of PET emitting glass microspheres. Successful completion of the proposed Phase IIB research will lead to PET-enabled Y-90 glass microspheres to improve patient safety and to advance Y-90 radioembolization from palliative treatment to curative treatment for liver cancer, especially primary liver cancer. In addition, this Phase IIB advanced development has the potential to drastically reduce the cost of Y-90 radioembolization agents so that this treatment option is more affordable in addition to being more effective.