Intraoperative MRI for giant cell tumor of bone after denosumab and other selected tumors: A pilot study

Background Although intraoperative magnetic resonance imaging (iMRI) is well established in neurosurgery, its role in musculoskeletal oncology remains unclear. Purpose To assess the feasibility and safety of iMRI in bone and soft tissue tumor surgery, focusing on giant cell tumor of bone (GCTB) after denosumab. Material and Methods Fourteen patients (12 GCTB, 1 undifferentiated pleomorphic sarcoma [UPS], 1 chondroblastoma) underwent tumor resection with intraoperative 0.4 T MRI between 2017 and 2024. Outcomes included residual tumor detection, recurrence, and safety. Results iMRI identified residual tumor in 7 of 12 GCTB patients (58.3%), all histologically confirmed. At a median follow-up of 42 months, recurrence occurred in one GCTB case (8.3%). iMRI guided complete resection in a femoral head chondroblastoma, enabling full functional recovery. Soft tissue assessment was limited in the UPS case. No iMRI-related complications occurred. Conclusion iMRI is a feasible and safe adjunct in bone tumor surgery, enhancing detection of residual tumor and supporting joint-preserving procedures, particularly in GCTB after denosumab.