Advances in Radiation Therapy for Primary Bone Malignancies.

Primary bone malignancies - including chordoma, chondrosarcoma, osteosarcoma, and Ewing sarcoma - originate from bone or cartilage cells and often develop in anatomically complex or surgically challenging regions. While surgical resection remains the standard of care for most localized tumors, radiation therapy (RT) has become an increasingly integral component of multidisciplinary management, particularly when complete surgical excision is not feasible, margins are close or positive, or the tumor is adjacent to critical structures. Historically, conventional photon-based RT has shown limited efficacy in many of these tumors due to factors such as relative radioresistance and proximity to radiosensitive normal tissues. However, advances in conformal photon techniques such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT), along with hadron-based approaches like proton beam therapy (PBT) and carbon ion radiation therapy (CIRT), have expanded the therapeutic potential of RT in bone sarcomas. This review highlights the evolving role of RT in the management of primary bone malignancies, with a focus on technological advances, clinical outcomes, ongoing trials, and future directions in the field.