GPRC5D Targeted PET/CT Imaging in Plasma Cell Disorders

This is a prospective, single-center, single-arm Phase I study evaluating GPRC5D-targeted PET/CT imaging in patients with plasma cell disorders, including multiple myeloma. Participants will undergo GPRC5D-targeted PET/CT, 18F-FDG PET/CT, and 68Ga-BCMA PET/CT within 5 days whenever feasible for head-to-head comparison of lesion detection and disease assessment. The study aims to evaluate the safety, feasibility, biodistribution, and diagnostic performance of GPRC5D-targeted PET/CT and to compare its imaging characteristics with currently available molecular imaging modalities in plasma cell disorders.

Inclusion Criteria: * Adults with confirmed or suspected plasma cell disorders, including multiple myeloma. * Healthy volunteers eligible for PET/CT imaging may also be enrolled. * Availability of recent clinical laboratory results within 1 week prior to imaging, when applicable. * Ability to undergo PET/CT imaging procedures. * Ability to understand the study requirements and provide written informed consent. Exclusion Criteria: * History of other active malignant tumors, unless considered clinically insignificant by the investigator. * Pregnant or breastfeeding women. * Inability to understand study procedures or comply with imaging examinations. * Any medical or psychiatric condition that, in the investigator's judgment, may interfere with study participation or image interpretation.