Optimizing imaging modalities for sarcoma subtypes in radiation therapy: State of the art

The choice of imaging modalities is essential in sarcoma management, as different techniques provide complementary information depending on tumor subtype and anatomical location. This narrative review examines the role of imaging in sarcoma characterization and treatment planning, particularly in the context of radiation therapy (RT). Magnetic resonance imaging (MRI) provides superior soft tissue contrast, enabling detailed assessment of tumor extent and peritumoral involvement. Computed tomography (CT) is particularly valuable for detecting osseous involvement, periosteal reactions, and calcifications, complementing MRI in sarcomas involving bone or calcified lesions. The combination of MRI and CT enhances tumor delineation, particularly for complex sites such as retroperitoneal and uterine sarcomas, where spatial relationships with adjacent organs are critical. In vascularized sarcomas, such as alveolar soft-part sarcomas, the integration of MRI with CT or MR angiography facilitates accurate mapping of tumor margins. Positron emission tomography with [18 F]-fluorodeoxyglucose ([18 F]-FDG PET) provides functional insights, identifying metabolically active regions within tumors to guide dose escalation. Although its role in routine staging is limited, [18 F]-FDG PET and emerging PET tracers offer promise for refining RT planning. Advances in artificial intelligence further enhance imaging precision, enabling more accurate contouring and treatment optimization. This review highlights how the integration of imaging modalities, tailored to specific sarcoma subtypes, supports precise RT delivery while minimizing damage to surrounding tissues. These strategies underline the importance of multidisciplinary approaches in improving sarcoma management and outcomes through multi-image-based RT planning.