Current Position of Nuclear Medicine Imaging in Primary Bone Tumors

Abstract

Primary bone tumors encompass a heterogeneous spectrum ranging from benign entities to highly aggressive sarcomas. This review aims to summarize the current role and future perspectives of nuclear medicine in the diagnosis, staging, and management of primary bone tumors. Accurate diagnosis and staging are critical yet challenging due to histologic heterogeneity and overlapping imaging features. While radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) remain essential, nuclear medicine provides a complementary functional perspective by assessing bone turnover, vascularity, and glucose metabolism. Bone scintigraphy is highly sensitive for skeletal lesions and useful for detecting skip lesions or multifocal disease, although its specificity is limited. Hybrid single-photon emission computed tomography (SPECT)/CT enhances diagnostic confidence through precise anatomic localization and quantitation. [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET)/CT, by directly visualizing tumor metabolism, has become a cornerstone in osteosarcoma and Ewing sarcoma management, demonstrating superiority over bone scintigraphy for detecting skeletal metastases. In chondrosarcoma, [18F]FDG uptake correlates with histologic grade, although overlap with benign cartilage tumors complicates interpretation. Future directions include the integration of quantitative SPECT, artificial intelligence, and novel tracers such as [18F]sodium fluoride and [68Ga]Ga-fibroblast activation protein inhibitor (FAPI). Collectively, nuclear medicine imaging is becoming a key element in musculoskeletal oncology, offering unique biological insights that complement anatomic imaging and contribute to improved patient management.