Rethinking the role of bisphosphonates after denosumab treatment in locally advanced or unresectable aneurysmal bone cysts: A meta-analysis

Figure 1 Cumulative survival estimates of local-progression free survival in ABC after denosumab withdrawal. Blue line: Group 1; Broun line: Group 2, (P value = 0085). The tables provide details of time, events, censored cases, and survival rates in both groups. A: Local-progression free survival; B: Details time, events, censored cases, and survival rate.

Figure 2 Aneurysmal bone cysts of the left pelvic bones. A: Frontal computed tomography (CT) scans before denosumab therapy (DT); B: Frontal CT scans 12 months after initiation of DT demonstrate more pronounced ossification and demarcation of the tumor margin; C: Planar bone scintigraphy after DT showing intensive tracer uptake in the ossified tumor (arrow). Bladder accumulating excreted ^99mTc-BP is dislocated to the right.

Figure 3 Rapidly growing recurrent aneurysmal bone cysts of metacarpal bones II-III after multiple decompressions and intralesional surgery with cement spacer placement. A: Radiographs before bisphosphonates (BPs) therapy with pamidronate; B: Radiographs after six BP infusions showing treatment-induced ossification; C: Radiographs after the removal of an ossified tumor with the reconstruction of metacarpal bones with free fibula autografts and microvascular anastomoses.

Figure 4 Tentative algorithm of anti-resorptive therapy for locally advanced or inoperable aneurysmal bone cysts. ¹Immediate surgery is required in spinal tumors with instability or progressive neurological deficit; ²bisphosphonates (BPs) as definitive treatment; ³Denosumab for ≤ 6 months in an actively growing tumor; ⁴BPs to prevent rebound hypercalcemia and achieve long-term local control; ⁵Denosumab for ~ one year in an actively growing tumor; ⁶BPs to achieve long-term local control; ⁷Second-look surgery if deemed operable without high morbidity.