A modified Delphi consensus on tenosynovial giant cell tumour and giant cell tumour of bone : a report from the Birmingham Orthopaedic Oncology Meeting (BOOM)

Abstract

Aims: The aim of this study was to achieve consensus on important topics related to tenosynovial giant cell tumour (TGCT) and giant cell tumour of bone (GCTB), and to identify areas for future research. Methods: In January 2026, a consensus meeting, The Birmingham Orthopaedic Oncology Meeting (BOOM), held in Cape Town, South Africa, gathered 314 delegates from 59 countries to debate 21 consensus statements on tenosynovial giant cell tumour (TGCT) and giant cell tumour of bone (GCTB) through a modified Delphi process. Results: Of the 21 statements, two achieved unanimous consensus, 18 strong consensus, and one moderate consensus. Unanimous consensus was reached for prioritizing joint-preserving intralesional curettage in GCTB when feasible, and for supporting non-surgical approaches in anatomically challenging cases, particularly sacral lesions. The statement addressing the role of denosumab in GCTB achieved only moderate consensus. The use of adjuvants in GCTB, as well as the management of recurrent and systemic GCTB, including long-term use of denosumab, reached strong consensus. Strong consensus was achieved in the surgical and non-surgical management for both primary and recurrent TGCT. Surveillance strategies for both TGCT and GCTB generated substantial discussion despite strong consensus, reflecting ongoing uncertainty and lack in evidence. Conclusion: This international consensus provides practical guidance for the management of TGCT and GCTB while identifying important gaps in evidence. Joint-preserving surgery remains central to the treatment of GCTB, with selective integration of systemic therapies and individualized surveillance. The consensus framework highlights priorities for future collaborative research in orthopaedic oncology.